Article

A novel approach to compare building-integrated photovoltaics/thermal air collectors to side-by-side PV modules and solar thermal collectors

February 2014
Solar Energy 100:50–65

DOI:10.1016/j.solener.2013.09.040

Authors:

Natural Resources Canada

Building-integrated photovoltaics with thermal energy recovery (BIPV/T) shows great potential for integration into net-zero energy buildings. This technology is still not widely used, however. One of the reasons is that its advantages compared to traditional PV modules and solar thermal collectors are unclear. This study addresses the lack of a methodology on how to perform such comparison. It also presents a case study on how this novel approach can be used to demonstrate the actual energy and economic benefits of BIPV/T air systems compared to side-by-side PV modules and solar thermal collectors for residential applications. In this methodology, the thermal energy produced by both systems is transferred into water using a heat exchanger and the concept of annual equivalent useful thermal energy production is used to combine thermal and electrical energy. To perform the analysis, a detailed model of a BIPV/T system was developed and validated against experimental data. Then, the following systems were modeled in TRNSYS: a BIPV/T air system and side-by-side PV modules and liquid solar thermal collectors (PV + T). A case study was performed by simulating the performance of both systems on a 40 m2 south-facing roof located in Montreal, Canada. The total energy produced by both systems was assessed by converting electricity into heat with various conversion factors. For a factor of 2, the BIPV/T system was found to produce 5–29% more equivalent useful thermal energy than the PV + T system for a water temperature at the heat exchanger inlet corresponding to 10 °C. Under similar operating conditions and for systems operating all year long, the acceptable cost to recover the heat from the BIPV system in order to break even with the cost of the PV + T system was found to be 7000 CAD.

A review on futuristic aspects of hybrid photo-voltaic thermal systems (PV/T) in solar energy utilization: Engineering and Technological approaches

Article

Oct 2022

The aim of the presented review is based on recent past research and ongoing practices in the area of Photovoltaic Thermal (PVT) technology and thereby to explore the challenges and suggest practical solutions leading to the development of an efficient working system. Current development in technologies and its engineering applications are based on further development in materials, process parameters and modelling and simulations based solutions. These issues well addressed in review process. Investigative review intends to explore progressive advances in materials and their applications in PV/T devices, process parameters and optimizations models to reach optimum working efficiencies. Integration of PV/T systems with buildings given focused attention. Synergistic correlation among three subdomains can lead to the dynamic working system based on optimized utilization of thermal and photosensitive spectrum of solar radiation. The study elucidates the inception of PVT technology as a non-concentrating type of system, incubating the idea of utilizing it as a process enhancing system. Besides these, it is further extended to the concentrated type of PVT systems using varying material intervention with an essential milestone of attaining an efficient built environment system by conceptualizing multifaceted utilization of PVT as Building Integrated Photovoltaic Thermal (BIPVT).

A novel methodology to compare between side-by-side photovoltaics and thermal collectors against hybrid photovoltaic thermal collectors

Article

Oct 2019
ENERG CONVERS MANAGE

Hybrid photovoltaic/thermal collectors (PV/Ts) have evolved as a new technology that can intervene with trigeneration systems to form a polygeneration system. Accordingly, many studies have compared the performance of side-by-side Photovoltaics (PVs) and Solar collectors (SCs) against PV/Ts based on several criteria. However, these comparisons between both configurations depended on the performance of these components as individual components not on a system basis. A methodology of real system-level comparison is presented in contrary to component-level comparisons that are available in the open literature. This methodology depends on comparing an optimized Solar-CCHP system side-by-side PVs and SCs, against a PVT-CCHP system with (PV/Ts) instead under a constrained area. The comparison is under the constraints of maximizing a formulated combined efficiency that combines energy, economy, environment and exergy aspects. Results showed that the PVT-CCHP system has higher combined efficiency but with lower NPV. Another novel contribution for determining the actual selling price of both sold CCHP-electricity and Solar-electricity is presented. It's used for carrying out a sensitivity analysis on the selling price. Results showed that by increasing the selling price, the PVT-CCHP system achieved higher combined efficiency and NPV. These results assured the importance of comparing energy systems based on the system-comparison methodology as this methodology guarantees more improvement in system performance after allowing the configuration, sizing and scheduling of the original CCHP system to change after the solar intervention. Moreover, they came up with the conclusion that using PV/Ts instead of side-by-side PVs and SCs will yield higher combined efficiency but with lower NPV at proposed price mode but with increasing the selling prices of sold electricity, PV/Ts are favorable due to higher combined efficiency and NPV.

Solar driven water heating systems for medium-rise residential buildings in urban mediterranean areas

Article

Sep 2019
RENEW ENERG

International Energy Agency reported that buildings are accountable for one-third of the global final energy demand in 2017. On-site renewable energy generation can reduce buildings' grid electricity consumptions. Medium-rise buildings located in urban areas have limited available rooftop or facade surfaces, thus solar driven technologies such as solar thermal, photovoltaics (PV) or photovoltaics/thermal (PV/T) are in competition for the available space. This investigation aims to compare available solar driven water heating systems in the market, suitable to replace the conventional electric water heater for a multi-residential building. Under the present study, solar PV electric water heating system (S1), solar thermal water heating system with electric boosting (S2), solar PV/T water heating system with electric boosting (S3) and integrated solar PV and heat pump water heating system (S4) are investigated. The performance parameters compared are the annual net electricity consumption from the grid and the net present value of life-cycle cost (LCC) for 20 years life. Results reveal that S3 and S4 have ‘net’ positive electricity production but higher initial costs, compared to the other systems. For buildings located in colder climates, S2 has lower LCC compared to S3 but for warmer climates the LCC of S3 is the lowest.

Theoretical Study and Experimental Validation of Energetic Performances of Photovoltaic/Thermal Air Collector

Article

Full-text available

Dec 2018
INT J PHOTOENERGY

This work undertakes both simulation and experimental studies of a new design of a photovoltaic thermal solar air collector (PV/T). In order to improve the thermal and electrical performances for a specific application, the analytical expressions for thermal parameters and efficiency are derived by developing an energy balance equation for each component of the PV/T air collector. This type of hybrid collector can be applied in the facades of buildings. The electricity and heat produced will satisfy the energy needs of the buildings, while ensuring an aesthetic view of its facades. A typical prototype was designed, constructed, and implemented in the applied research unit on renewable energies in Ghardaia, situated in the south of Algeria. This region has semiarid characteristics. Results obtained by an experimental test are presented and compared to those predicted through simulation. Results include the temperature of each component of the PV/T collector and air temperature at the inlet and outlet of the channel. It has been found that the theoretical results predicted by the developed mathematical model, for instance, outlet temperature, agree with those found through experimental work.

Modelling and simulation of Net Zero Energy Buildings by renewable energy and distributed electric generation

Conference Paper

Oct 2017

As buildings play a crucial role in terms of fossil fuel consumption and carbon oxide emissions, development of integrated sustainable energy strategies, from energy generation to storage and transportation, has gained a great attention. In this regard, solar houses and mobility electric storage systems are considered as an effective energy storage strategy toward the goal of a sustainable built environment and a cleaner mobility. In net zero energy buildings (NZEBs), the energy generated by off-site resources should be matched or even exceeded by on-site renewable generation, designated for the building itself or exported to the grid. To this aim, NZEBs could effectively take advantages from plug-in electric vehicles. These could be considered as additional high-power appliances (increasing the residential electricity consumption) and as house electricity sources (accelerating the development of NZEBs and promoting the deployment of renewable energy sources). This paper focuses on distributed electric storages, residential energy use and power generation, contributing to the state-of-the-art. In particular, this paper presents a case study on a residential NZEB, equipped with building-integrated photovoltaic collectors, which produce electricity, directly used or stored in batteries, including and electric vehicle one (known as Vehicle-to-Home, V2H), in order to balance the total building energy needs, or delivered to the grid in case of surplus. To this aim, a dynamic simulation model, implemented in Matlab, is suitably developed for the assessment of the energy demands and loads of the building, as a function of the considered electric vehicles energy use patterns. As batteries of electric cars are sufficient to supply one household with power for several days, energy stored in the vehicle battery is supplied to the home when at times of increased energy demands in order to reduce the energy operating costs. Simulation results showed that thanks to the combination of a home and an electric vehicle battery, the building grid reliance is optimized. Finally, with the help of this system, the grid electricity consumption is effectively reduced by up to 2% compared to that of a traditional building design.

Performance of Air Based BIPV/T Heat Management Strategies in a Canadian Home

Article

Full-text available

Dec 2017

Using TRNSYS, the performance of three heat management strategies of an air-based Building Integrated Photovoltaic/Thermal (BIPV/T)system in an energy efficient home are assessed. The first scenario makes direct use of the heated air as fresh air supplied to aheat recovery ventilator. The second scenario uses the heated air from the BIPV/T collector as a source for the outdoor unit of an air source heat pump. The third strategy involves storing the energy from the BIPV/T collector heated air in an ice-slurry latent storage tank that is coupled with a water source heat pump. These strategies are evaluated in reference to a base case scenario with a simple air–based ducted system without a BIPV/T collector. Results show that using a latent storage medium such as ice can potentially bridge the time gaps between available solar radiation and domestic space heating loads.

A review on building-integrated photovoltaic/thermal systems for green buildings

Article

Full-text available

Apr 2023
APPL THERM ENG

Comparison of BIPV and BIPVT: A review

Article

Full-text available

Sep 2017

Building-Integrated Photovoltaic (BIPV) is a smart energy production system that incorporates solar PV panels as part of the roof, windows, facades and shading devices. When active heat recovery is combined with BIPV systems either in closed loop (like PV-T with liquid loop) or in an open loop with forced air they are known as building-integrated photovoltaic-thermal (BIPVT systems). This paper reviews the BIPV and BIPVT technology. The paper shows various technologies involved in BIPV and BIPVT as well as their function, cost and aesthetics. In addition a review of the application of BIPV and BIPVT installations is described. In comparison to BIPV systems, BIPVT system has significant benefits and potential for wide use in buildings. The building integrated photovoltaic-thermal system design (BIPVT) is also becoming popular among architects and design engineers.

An approach to enhancing energy performance in residential buildings in hot climate regions (The case of Saudi Arabia)

Article

Jul 2022

Mana Alyami

Saudi Arabia, like many developing countries, is experiencing rapid urbanisation and infrastructure expansion, especially in the area of residential buildings. As an oil-producing nation with an extremely hot climate, the country is also renowned for high rates of energy consumption and carbon emissions. The construction sector is no exception, accounting for approximately 80% of total national electricity consumption, with residential cooling demand consuming almost 66% of domestic energy use. Although sustainability has now become a major focus for the Saudi government, with sustainable development being a key goal of the country’s economic and social development plan, the Saudi Vision 2030, the lack of energy efficiency in Saudi buildings has yet to be given serious consideration. However, with current demand threatening long-term energy security and forecasts indicating that domestic energy consumption will rise at a rate of 5% to 7% annually, it is crucial to improve the energy and environmental performance of the building stock. In order to support sustainable development within the Saudi residential sector, this study identifies the main causes of high energy consumption in the sector and the key barriers to enhancing building energy performance from a design and operational perspective, including environmental, economic and socio-cultural factors. It goes on to explore a number of possible solutions, assessing their effectiveness via simulation and calculating cost benefits in order to identify the optimal energy efficiency measures. These are then tested against local building regulations and benchmarked against international low-energy standards. The most effective measures are incorporated into a proposed framework for energy-efficient building design in the Saudi context, which takes local environmental, economic and socio-cultural factors into account. The framework covers both new builds and retro-fitting and constitutes one of the main contributions of this research. The study was performed in four stages, each utilising a specific methodology. Stage one involved an exploratory public survey, distributed electronically, designed to gauge public awareness of the benefits of sustainable building design and to identify design and operation factors causing energy consumption in residential buildings. Next, an existing family villa, representing a typical dwelling type in Saudi Arabia, was selected for modelling purposes and examined to identify design weaknesses. The third stage involved a consultation with experts in the field to assess current building issues and identify viable solutions in the local context. A model was then created using DesignBuilder simulation software, and its energy performance validated using data collected from the case study villa. Additional simulations targeting building design and operating parameters to enhance energy efficiency were also analysed to establish the optimal solutions within the local context. The use of surveys, a case study, and computer simulations to collect and validate the results is considered appropriate for the purposes of proposing energy strategies for residential buildings in hot climates. The findings indicate that much of the high energy consumption in the residential sector results from poor building design and construction techniques, inefficient operating practices, a lack of stakeholder engagement, and an absence of coordinated enforcement. However, the results of the simulations show that energy consumption and peak electricity demand could be reduced significantly by implementing the optimal strategies proposed in the framework. A potential reduction of 68% in total electricity consumption and 74% in peak electricity demand was shown to be possible, with an 81% reduction in cooling energy use intensity (EUI) bringing Saudi Arabia within the range of recommended European standards. Analysis of the improvement simulations also indicated that a reduction of 80% in carbon emissions was achieved in comparison with the base case study building. This amounted to almost 23 tonnes of CO₂ avoided annually and was equivalent to nearly five cars not being used per year. The cost-saving analysis employed to determine the economic viability of incorporating the proposed techniques indicated a typical payback period of 7 years, average annual savings of 1,603 USD, and total operational cost savings of up to 51% over a 30-year period. By incorporating the optimal sustainable design features, energy-efficiency measures, and renewable solar energy technologies proposed in the framework, the representative home was transformed into an energy-efficient structure. This study demonstrates that relatively simple strategies can significantly reduce residential energy demand in hot climate conditions and that the strategies in the proposed framework are effective. These findings have significant implications for building sector professionals, policy-makers and building occupants. A dramatic reduction in energy consumption would save costs, reduce CO₂ emissions, alleviate the need to increase power generation capacity, and enhance the country's profile internationally, resulting in significant environmental, economic, and social benefits. However, this cannot be achieved without support from the government, the housing industry; and the general public, so the study concludes by recommending further measures to support the development of a sustainable building sector in Saudi Arabia in line with the aims expressed in Vision 2030.

Intelligent windows for electricity generation: A technologies review

Article

Full-text available

Mar 2022

Buildings are responsible for over 40% of total primary energy consumption in the US and EU and therefore improving building energy efficiency has significant potential for obtaining net-zero energy buildings reducing energy consumption. The concurrent demands of environmental comfort and the need to improve energy efficiency for both new and existing buildings have motivated research into finding solutions for the regulation of incoming solar radiation, as well as ensuring occupant thermal and visual comfort whilst generating energy onsite. Windows as building components offer the opportunity of addressing these issues in buildings. Building integration of photovoltaics permits building components such as semi-transparent façade, skylights and shading devices to be replaced with PV. Much progress has been made in photovoltaic material science, where smart window development has evolved in areas such as semi-transparent PV, electrochromic and thermochromic materials, luminescent solar concentrator and the integration of each of the latter technologies to buildings, specifically windows. This paper presents a review on intelligent window technologies that integrate renewable energy technologies with energy-saving strategies contributing potential solutions towards sustainable zero-energy buildings. This review is a comprehensive evaluation of intelligent windows focusing on state-of-the-art development in windows that can generate electricity and their electrical, thermal and optical characteristics. This review provides a summary of current work in intelligent window design for energy generation and gives recommendations for further research opportunities.

Modeling a novel building-integrated PVT-air-collector system coupled to a heat pump using open source libraries

Conference Paper

Full-text available

Oct 2021

A novel building-integrated photovoltaic and thermal collector (BIPVT), in form of a solar roof tile (SRT), is developed. To enable futher optimization, a quasi-steady model is presented, which is capable to simulate the electrical and thermal output. The open-source libraries pv-lib and TESPy are used and the model is calibrated with a CFD simulation of the SRT. A first exemplary thermal energy concept for a single family house is set up with the SRT preheating the air for a mono-energetic bivalent air-source heat pump for heating and domestic hot water. The simulation over one year with a simple rule-based forecasting algorithm shows an increase of the annual COP by about 2.3 %. A validation with measurements is planned. Other energy concepts, such as direct usage of the hot air for preheating a thermal storage or to regenerate borehole thermal storages in a district heating system will be subject to further research.

A Ducted Photovoltaic Façade Unit with Buoyancy Cooling Part I Experiment

Chapter

Full-text available

Jan 2021

Abdel Rahman Elbakheit

A Review of Retrofit Interventions for Residential Buildings in Hot Humid Climates

Article

Full-text available

May 2020

Buildings consume 40% of resources around the world, low energy building is fast becoming a major component of sustainable development. However, limiting the concept of low energy buildings to new builds will only undermine its effects and benefits as there are numerous existing buildings that consume uneconomical energy resources irrespective of how energy efficient the new ones are. Therefore, retrofit interventions to existing buildings is important in decreasing resource consumption and increasing energy efficiency. Some various retrofit interventions already exist towards reducing energy consumption in residential buildings but deciding on a specific retrofit intervention needs assiduous consideration. Hence, this paper focuses on the review of retrofit interventions and their energy performances. It was found amongst others that clay bricks, sand line, and pre-fabricated walls consume less energy than concrete bricks by 16%, 23%, and 25% respectively. Electrochromic glazing system with no shading device was also found to have reduced heat gains by 53%-59% in winter and summer. It was concluded that further research would benefit from the combination of the various interventions to create pathways for building retrofit in hot humid climate, the pathways can be tested with a dynamic thermal simulation software for energy performance.

On the Implementation of the Nearly Zero Energy Building Concept for Jointly Acting Renewables Self-Consumers in Mediterranean Climate Conditions

Article

Full-text available

Feb 2020

Cost-effective energy saving in the building sector is a high priority in Europe; The European Union has set ambitious targets for buildings’ energy performance in order to convert old energy-intensive ones into nearly zero energy buildings (nZEBs). This study focuses on the implementation of a collective self-consumption nZEB concept in Mediterranean climate conditions, considering a typical multi-family building (or apartment block) in the urban environment. The aggregated use of PVs, geothermal and energy storage systems allow the self-production and self-consumption of energy, in a way that the independence from fossil fuels and the reliability of the electricity grid are enhanced. The proposed nZEB implementation scheme will be analyzed from techno-economical perspective, presenting detailed calculations regarding the components dimensioning and costs-giving emphasis on life cycle cost analysis (LCCA) indexes—as well as the energy transactions between the building and the electricity grid. The main outcomes of this work are that the proposed nZEB implementation is a sustainable solution for the Mediterranean area, whereas the incorporation of electrical energy storage units—though beneficial for the reliability of the grid—calls for the implementation of positive policies regarding the reduction of their payback period.

Long-term performance and GHG emission offset analysis of small-scale grid-tied residential solar PV systems in northerly latitudes

Article

Jan 2020

The integration of solar energy systems into residential buildings is an emerging trend worldwide and is an important method of mitigating the impact of housing on greenhouse gas (GHG) emissions. To achieve optimal energy performance, particularly in cold-climate regions, the generating capacity of solar photovoltaic systems (PVs) as well as their corresponding GHG emissions offsets must be investigated. In the present paper the energy generation of 86 PV sites in northerly latitudes is analysed to investigate their actual long-term performance considering various parameters. Energy payback time (EPBT) and GHG emissions of the monitored PV systems are also investigated and key parameters influencing both EPBT and GHG emissions are identified. Results indicate that there is a correlation between a solar PV layout setting and its EPBT and GHG emissions. Other results include the solar PV potential benchmarking in each of the cities where the study is conducted and the recommended layout placement in order to maximise the annual energy aggregate of PV systems and thus minimize their EPBT and GHG emissions.

A Ducted Photovoltaic Façade Unit with Buoyancy Cooling: Part I Experiment

Article

Full-text available

Apr 2019

Abdel Rahman Elbakheit

A ducted photovoltaic façade (DPV) unit was studied using experimental prototype and simulated in a full scale computational fluid dynamics (CFD) model. The study comes in two parts; this is Part I, as detailed in the title above, and Part II is titled “A Ducted Photovoltaic Façade Unit with Buoyancy Cooling: Part II CFD Simulation”. The process adopted in the experimental study is replicated in the simulation part. The aim was to optimize the duct width behind the solar cells to allow for a maximum buoyancy-driven cooling for the cells during operation. Duct widths from 5 to 50 cm were tested in a prototype. A duct width of 45 cm had the maximum calculated heat removed from the duct; however, the lowest cell-operating temperature was reported for duct width of 50 cm. It was found that ΔT between ducts’ inlets and outlets range from 5.47 °C to 12.32 °C for duct widths of 5–50 cm, respectively. The ducted system enhanced module efficiency by 12.69% by reducing photovoltaic (PV) temperature by 27 °C from 100 °C to 73 °C. The maximum measured heat recovered from the ducted PV system was 422 W. This is 48.98% from the incident radiation in the test. The total sum of heat recovered and power enhanced by the ducted system was 61.67%.

A Ducted Photovoltaic Façade Unit with Buoyancy Cooling: Part I Experiment

Preprint

Full-text available

Apr 2019

Abdel Rahman Elbakheit

A ducted photovoltaic façade (DPV) unit Studied using experimental Prototype and simulated in a full scale Computational Fluid Dynamics CFD Model. The Study comes in two parts; This is Part I with the title detailed above and Part II titled ‘A Ducted Photovoltaic Façade Unit with Buoyancy Cooling: Part II CFD Simulation’.. The process adopted in the experimental study is replicated in the simulation Part. The aim was to optimize the duct width behind the solar cells to allow for maximum buoyancy-driven cooling for the cells during operation. Duct widths from 5 to 50 cm were tested in a Proto-type. A duct width of 45 cm had the maximum calculated heat removed from the duct; however, the lowest cell-operating temperature was reported for duct width of 50 cm. It was found that the DT between ducts' inlets and outlets range from 5.47 °C to 12.32 °C for duct widths of 5–50 cm, respectively. The ducted system enhanced module efficiency by 12.69% by reducing PV temperature by 27 °C from 100°C to 73 °C. The maximum calculated heat recovered from the ducted PV system is 422 W. This is 47.98% from the incident radiation in the test. Total summation of heat recovered and power enhanced by the ducted system is 61.67%.

Experimental and numerical study of a PV/Thermal collector equipped with a PV-assisted air circulation system: Configuration suitable for building integration

Article

Mar 2019
ENERG BUILDINGS

Modeling of solar energy systems using artificial neural network: A comprehensive review

Article

Jan 2019
SOL ENERGY

The development of different solar energy (SE) systems becomes one of the most important solutions to the problem of the rapid increase in energy demand. This may be achieved by optimizing the performance of solar-based devices under some operating conditions. Intelligent system-based techniques are used to optimize the performance of such systems. In present review, an attempt has been made to scrutinize the applications of artificial neural network (ANN) as an intelligent system-based method for optimizing and the prediction of different SE devices' performance, like solar collectors, solar assisted heat pumps, solar air and water heaters, photovoltaic/thermal (PV/T) systems, solar stills, solar cookers, and solar dryers. The commonly used artificial neural network types and architectures in literature, such as multilayer perceptron neural network, a neural network using wavelet transform, Elman neural network, and radial basis function, are also briefly discussed. Different statistical criteria that used to assess the performance of artificial neural network in modeling SE systems have been introduced. Previous studies have reported that artificial neural network is a useful technique to predict and optimize the performance of different solar energy devices. Important conclusions and suggestions for future research are also presented.

Building to vehicle to building concept toward a novel zero energy paradigm: Modelling and case studies

Article

Mar 2019
RENEW SUST ENERG REV

Download at: https://www.sciencedirect.com/science/article/pii/S1364032118307354?dgcid=coauthor This paper proposes and analyses a novel energy management system for buildings connected in a micro-grid, by considering electric vehicles as active components of such energy scheme. Renewable energy sources, PV, energy storage systems and bidirectional electricity exchange with the buildings and the grid are taken into account. The considered energy scheme, Building to Vehicle to Building, is analysed by including both buildings and mobility consumptions in the energy balance. Three different management system scenarios, designed to analyse the role of electric vehicles as electricity vector among buildings integrating PV panels and electrical storages, are analysed through a case study analysis. To this aim, a dynamic simulation model, implemented in MatLab, is suitably developed for the assessment of the energy demands and loads of the building, as a function of the considered electric vehicles energy use patterns. Simulation results show that the building grid reliance is optimized and the grid electricity consumption is remarkably reduced up to 45 and 77% depending on the proposed scenarios. Their energy exchange options also enhanced the energy-matching indexes. The economic analysis highlights the economic viability of the system, as well as the need of suitable funding policies to support the development of such micro-grid systems.

A techno-economic analysis for an integrated solar PV/T system for building applications

Conference Paper

Dec 2016

Assessment of Building Integrated Photovoltaic (BIPV) for sustainable energy performance in tropical regions of Cameroon

Article

Dec 2017
RENEW SUST ENERG REV

Cameroon produces 1292 MW of electricity out of which 57% is through hydraulic resources and the remaining 43% through fossil fuels resources. The access to this electricity is limited to 10% of population in the rural areas and 50% in the urban areas. To meet the demand of electricity for domestic purpose as well as for businesses, farms and manufacturing, the squeeze on resources will become unsustainable unless renewable resources become part of the mix. In this paper, the review of Building Integrated Photovoltaic (BIPV) systems and its potential in the tropical region is presented. An analysis is made for a residential apartment fitted with BIPV as roof top in tropical climate of Cameroon to meet principle energy demand of 3 kW per day. Modelling of the system is done to predict the indoor air temperatures and humidity (IATH) considering all the internal heat sources and thermal insulation of the envelope. The analysis shows that such system is capable of reducing annual primary energy consumption from 79.58 kW h/m² to 13.64 kW h/m² in addition to reduction in the amount spent on building materials for structured roof and the labour.

A key review of building integrated photovoltaic (BIPV) systems

Article

Full-text available

May 2017

Renewable and sustainable energy generation technologies have been in the forefront due to concerns related to environment, energy independence, and high fossil fuel costs. As part of the EU’s 2020 targets, it is aimed to reach a 20% share of renewable energy sources in final energy consumption by 2020, according to EU’s renewable energy directive. Within this context national renewable energy targets were set for each EU country ranging between 10% (for Malta) and 49% (for Sweden). A large share of renewable energy research has been devoted to photovoltaic systems which harness the solar energy to generate electrical power. As an application of the PV technology, building integrated photovoltaic (BIPV) systems have attracted an increasing interest in the past decade, and have been shown as a feasible renewable power generation technology to help buildings partially meet their load. In addition to BIPV, building integrated photovoltaic/thermal systems (BIPV/T) provide a very good potential for integration into the building to supply both electrical and thermal loads. In this study, we comprehensively reviewed the BIPV and BIPVT applications in terms of energy generation amount, nominal power, efficiency, type and performance assessment approaches. The two fundamental research areas in the BIPV and BIPVT systems are observed to be i) improvements on system efficiency by ventilation, hence obtaining a higher yield with lowering the panel temperature ii) new thin film technologies that are well suited for building integration. Several approaches to achieve these objectives are reported in the literature as presented in this paper. It is expected that this comprehensive review will be beneficial to researchers and practitioners involved or interested in the design, analysis, simulation, and performance evaluation, financial development and incentives, new methods and trends of BIPV systems.

Comparison of BIPV and BIPVT: A review

Article

Full-text available

Dec 2016

A detailed thermal-electrical model of three photovoltaic/thermal (PV/T) hybrid air collectors and photovoltaic (PV) module: Comparative study under Algiers climatic conditions

Article

Feb 2017
ENERG CONVERS MANAGE

Thermal modelling of photovoltaic thermal (PVT) integrated greenhouse system for biogas heating:

Article

Oct 2016
SOL ENERGY

In this paper, the design and fabrication of photovoltaic thermal integrated greenhouse system (PVTIGS) for biogas heating has been done for climatic condition of IIT Delhi, India. PVTIGS can also be used for a number of applications like generating electricity, space heating, enhancing production of biogas, crop cultivation and crop drying, etc. Thermal modelling of proposed system (PVTIGS) without load has been developed based on energy balance equations. Further, with the help of thermal modelling the solar cell temperature, room temperature and solar cell efficiency have been calculated for a typical clear day of May. Experimental validation have been done on the basis of correlation coefficient (r) and root mean square percentage deviation (e) and found to be in fair agreement between theoretical and experimental values. Effect of packing factor, mass flow rate of air below module, absorptivity (degradation effect) and transmittivity (dusting effect) on thermal load levelling have been discussed. Electrical energy has been calculated and validated with experimental values. Further, thermal energy and overall thermal energy have been evaluated and found to be 11.18 kW h and 12.76 kW h respectively for a clear day without load.

Thermal performance evaluation of an active building integrated photovoltaic thermoelectric wall system

Article

Sep 2016
APPL ENERG

mojumder2016

Data

May 2016

BIPVT systems for residential applications: An energy and economic analysis for European climates

Article

Dec 2016
APPL ENERG

Performance enhancement of a Building-Integrated Concentrating Photovoltaic system using phase change material

Article

Full-text available

May 2016
SOL ENERG MAT SOL C

Building-Integrated Concentrated Photovoltaic (BICPV) systems integrate easily into built environments, replacing building material, providing benefits of generating electricity at the point of use, allowing light efficacy within the building envelope and providing thermal management. This paper presents a novel experimental evaluation of phase change materials (PCM) to enhance performance of low-concentration BICPV system via thermal regulation. Previous studies have primarily focussed on temporal and spatial studies of PCM temperature within the BIPV systems but the current work also discusses the effect of PCM on electrical parameters of the BICPV systems. Due to the inadequacy of the earlier reported model, a new analytical model is proposed and implemented with the in-house controlled experiments. Paraffin wax based RT42 was used within an in-house designed and fabricated PCM containment. An indoor experiment was performed using highly collimated continuous light source at 1000 W m−2. Results show an increase in relative electrical efficiency by 7.7% with PCM incorporation. An average reduction in module centre temperature by 3.8 °C was recorded in the BICPV–PCM integrated system as compared to the naturally ventilated system without PCM. Studies showed that PCM effectiveness varies with irradiance; an increase in relative electrical efficiency by 1.15% at 500 W m−2, 4.20% at 750 W m−2 and 6.80% at 1200 W m−2 was observed.

An improved design of photovoltaic/thermal solar collector

Article

Full-text available

Dec 2015
SOL ENERGY

An improved photovoltaic/thermal (PV/T) solar collector combined with hexagonal honeycomb heat exchanger was studied. It is a combination of photovoltaic panel and solar thermal components in one integrated system. The honeycomb was installed horizontally into the channel located under the PV module. Air, as heat remover fluid is made to flow through the honeycomb. The system was tested with and without the honeycomb at irradiance of 828W/m2 and mass flow rate spanning from 0.02kg/s to 0.13kg/s. It was observed that the aluminum honeycomb is capable of enhancing the thermal efficiency of the system efficiently. At mass flow rate of 0.11kg/s, the thermal efficiency of the system without honeycomb is 27% and with is 87%. The electrical efficiency of the PV module improved by 0.1% throughout the range of the mass flow rate. The improved design is suitable to be further investigated as solar drying system and space heating.

Application of support vector machine for prediction of electrical and thermal performance in PV/T system ( Tier 1)

Article

Nov 2015
ENERG BUILDINGS

In photovoltaic-thermal (PV/T) system analysis, solar collectors with numerous design concepts have been used to purvey the thermal and electrical energy effectively. In this study, two types of solar thermal collectors in PV/T system are proposed and fabricated called design A and design B respectively. In order to investigate the effects of collector type on the system performance a thin flat metallic sheet (TFMS) and fins were introduced as an effective heat absorber and heat sink in the collectors. Extensive experiments were carried out for different conditions under indoor solar simulator. Then PV/T thermal and electrical efficiency were calculated by using data obtained from experiments. Here, support vector machine (SVM) model is designed to estimate the thermal and electrical output which predicts the values for some input variables. For this purpose, three SVM models namely SVM coupled with the discrete wavelet transform (SVM-Wavelet), the firefly algorithm (SVM-FFA) and with using the radial basis function (SVM-RBF) were analyzed. The estimation and prediction results of these models were compared with each other using statistical indicators i.e. root means square error, coefficient of determination and Pearson coefficient. The experimental results show that a significant improvement in predictive accuracy and capability of generalization can be achieved by the SVM-Wavelet approach. Moreover, the results indicate that proposed SVM-Wavelet model can adequately predict the electrical and thermal efficiencies of PV/T system. In the final analysis, a proper sensitivity analysis is performed to identify the influence of considered input elements on performance prediction of PV/T system.

Solar energy for zero energy buildings – A comparison between solar thermal, PV and photovoltaic thermal (PV/T) systems

Conference Paper

Sep 2015
SOL ENERGY

In a net zero energy building, the energy needed to operate the building is met by renewable energy generated on site. Buildings require energy both in the form of heat and electricity, and hybrid photovoltaic-thermal (PV/T) modules are therefore an interesting technology for building applications. This paper describes a comparative simulation study of solar thermal, photovoltaic (PV) and PV/T systems on a Norwegian residential building model, with the objective to reach a net zero energy balance. The results show that PV/T systems can reach a higher energy output than separate solar thermal and PV installations, but the building with state-of-the-art PV modules only gets closest to meeting the nZEB requirements.

Economic and environmental analysis of the optimum design for the integrated system with air source heat pump and PVT

Article

May 2023

Solar Photovoltaic Thermal Collector as a Cogeneration Energy System: Conception and Recent Development in the Mediterranean Region

Chapter

Mar 2023

The increase in population is causing a major problem for the energy production sector worldwide. Moreover, a clean source of energy is required to have low greenhouse gases emissions. One of the most alternative available clean sources of energy is the solar energy which is renewable and sustainable. In this chapter, a study on solar photovoltaic thermal (PVT) collector is conducted. Energy as well as exergy analysis is presented thoroughly. Additionally, a review about Mediterranean countries’ energy consumption and production is presented in this chapter. Finally, a case study showing a detailed thermal-electrical model of different configurations of hybrid air collectors and photovoltaic (PV) module under Algiers climatic conditions is considered.KeywordsCogeneration systemConceptionPVT collectorSolar energy

Experimental investigation of a novel vertical loop-heat-pipe PV/T heat and power system under different height differences

Article

May 2022
ENERGY

For a novel vertical solar loop-heat-pipe photovoltaic/thermal system, the height difference between evaporator and condenser plays an important role in the heat transport capacity, which has significant impact on the solar thermal efficiency and parametrical optimization of this system. Therefore, based on the results derived from the authors’ previous analytical investigation and computer modelling studies, a prototype of this novel system was designed, constructed, and an experimental investigation under different height difference was undertaken to study the impact of height difference on the system performance. It was found that the relationship between the solar thermal efficiency of this vertical system and the height difference is nonlinear. In present study, the optimal height difference is around 1.1 m, which was selected as an optimal value for the following experimental investigations, and below 1.1 m, the PV module surface temperature decreased with the increase of the height difference. Furthermore, the transient solar thermal and electrical performance of this system with the selected optimal height difference was investigated under outdoor real weather condition. These results of this experimentation can help optimize the system construction and thus help to develop the high thermal performance and low-cost solar PV/T system for space heating and power generation.

Performance evaluation for the dielectric asymmetric compound parabolic concentrator with almost unity angular acceptance efficiency

Article

Jun 2021
ENERGY

This paper proposes a systematic design and formation process for the asymmetric compound parabolic concentrator taking the angular acceptance range as the target function and a dielectric asymmetric compound parabolic concentrator (DACPC) that presents almost unity angular acceptance efficiency is got. Ray-tracing simulation and experimental characterization study were conducted to reveal the optical performance of the DACPC. It was found that the DACPC with the geometric concentration ratio of 2.4 increased the short-circuit current and the maximum power by 87.0% and 96.6% averagely within the incidence angels of 0°—85° as compared with the non-concentrating photovoltaic cell. Corresponding average simulation and actual optical efficiency of it are 93.3% and 77.9%. The angular acceptance efficiency is proposed to evaluate the annual performance potential and regional applicability for optical concentrators, which indicates that the angular acceptance efficiency of the DACPC can be up to 97.7% for simulation results and 94.4% for experiment results. The outdoor experiments on 25th June when the projected incidence angle lied in the range of 60°—89° for the DACPC were conducted. It was found that the DACPC can still increase the short-circuit current and maximum power of the photovoltaic cell by average factors of 57% and 76% respectively.

Ultra-Wide Voltage Gain Range Microconverter for Integration of Silicon and Thin-Film Photovoltaic Modules in DC Microgrids

Article

May 2021
IEEE T POWER ELECTR

The paper overviews residential and building integrated photovoltaic (PV) module types. It demonstrates that existing dc-dc converter technologies do not allow building a universal interface microconverter because of wide dispersion of the parameters. However, the absence of universal microconverters limits the widespread adoption of PV modules despite great benefits for energy-efficient buildings and restrains the deployment of residential PV-based dc microgrids. Based on the design requirements formulated, a new approach utilizing a boost half-bridge front-end inverter and a three-mode reconfigurable rectifier is proposed. The paper describes the operating principle of the derived converter. The reconfigurable rectifier allows keeping the duty cycle of the input side within a favorable range of acceptable efficiencies. An experimental prototype rated for 360 W was assembled and tested in the entire operating range. The experimental results prove the ultra-wide input voltage range of over 1:20 and demonstrate the capability of the proposed concept to interface different PV module types while enabling their shade-tolerant operation.

A comprehensive study of feasibility and applicability of building integrated photovoltaic (BIPV) systems in regions with high solar irradiance

Article

Jul 2021
J CLEAN PROD

Building integrated photovoltaic (BIPV) systems at the building scale can not only reduce building energy consumption but also further promote the sustainable development of our society. To enhance the utilization of BIPV systems, this paper reviews their feasibility and applicability in regions with high solar irradiance from many perspectives. Specifically, this paper first investigates the application advantages of the BIPV system in terms of the energy supply and aesthetic value of buildings. Subsequently, several performance influencing factors of the BIPV in regions with high solar irradiance are analyzed independently, such as the PV module temperature, solar radiation intensity, PV module orientation and tilt angle, PV module types, and inverter. Simultaneously, the feasibility of the BIPV system in high solar-irradiance regions is systematically assessed in terms of energy efficiency, environmental benefit, and economic performance. And an ideal coordination model is highlighted to promote the development of the BIPV system. Additionally, the future research direction of the BIPV system in these regions is explored. Overall, this paper can provide valuable information for the development of BIPV systems in regions with high solar irradiance.

BIPV Potentials in Overcoming Energy Challenges in Sub-Saharan Africa

Conference Paper

Full-text available

Apr 2021

The incorporation of the solar panels to the building roof envelopes, also referred to as the building integrated photovoltaic (BIPV), is gradually gaining recognition in the energy-efficient systems. Apart from providing aesthetics, it is also a cost-effective, innovative, space-conservative, and pollution-free power generating technology from buildings. This technology is very economical because it helps to save the space required for PV panels that could be used for other infrastructural projects. an enormous power can be generated from buildings and added to the energy mix to help meet the increasing power demand. The BIPV potential for facades, rooftops, and windows is assessed in this article for Sub-Saharan African countries by evaluating the various methodologies that have been used globally, state of the art, and the relevant research areas for the future clean electricity harvesting schemes in buildings.

Overall efficiency improvement of photovoltaic-thermal air collector: numerical and experimental investigation in the desert climate of Ouargla region

Article

Jul 2020

In the Ouargla region, the desert area of Algeria, photovoltaic fields (PV) suffer from hard climate conditions with high-temperature levels. This temperature level causes a significant fall of PV cells efficiency which requires an integrated cooling system. For achieving this purpose, a thermal part based on airflow provided along a straight channel under the PV module (150 W) is added. It extracts the accumulated heat by air natural convection, then, the airflow passes through an upper glass extension (0.56 m) to reinforce the heat collection. The evaluation of the whole system performance is experimentally conducted by performing several variations of operating parameters and air channel depth. This photovoltaic-thermal (PV/T) system has modeled by a set of balanced energy equations that are resolved numerically using Matlab software. The experimental results show that the increase in the channel depth causes a significant reduction of thermal efficiency and a slight effect on the electrical one. The numerical data are compared and validated by the experimental results, where the characteristic curves (efficiencies, polarization, powers, temperatures) show good concordance with experimental data. The root means square of percentage deviation (RMSD) is between 1.75% and 16.25%. For a channel depth of 10 cm, the energy and exergy efficiency reach their mean values of 58.5% and 14.7%, respectively. The glass extension of 1.6 m gives a net improvement of 5% in the overall energy efficiency.

Design and experiment of a sun-powered smart building envelope with automatic control

Article

May 2020
ENERG BUILDINGS

A novel sun-powered smart window blind (SPSWB) system has been designed and developed for the smart control of building envelopes to achieve the optimal internal comfort with minimum energy expenditure. Its self-powered sensing, controlling, and actuation significantly simplify the installation and maintenance of the system. The energy is harvested by the attached thin-film photovoltaic cells, after which it is voltage-regulated for the permanent storage into a rechargeable battery with 55% energy efficiency. The excessive heat absorbed by the solar cells is dissipated by a PVdF-HFP porous coating with more than 9% temperature reduction. The smart control of the energy harvesting and the cooling is achieved based on the blinds’ surface temperature by an Arduino-based sensing, controlling, and actuating system, whose energy consumption is closely monitored. The energy equilibrium analysis is proposed for the self-powered design in any locations, and the optimal solar energy harvesting can be achieved by the proper adjustments of the window blinds angle with respect to the geographical location. The abundant energy that can be harvested validates the feasibility and the robustness of the system and proves its wide application potentials to the next generation of smart building envelope systems.

A comparative analysis on performances of flat plate photovoltaic/thermal collectors in view of operating media, structural designs, and climate conditions

Article

Nov 2019
RENEW SUST ENERG REV

It is well known the efficiency of photovoltaic (PV) modules decreases with an increase in operating temperature. In this paper, we have investigated this phenomenon through classification of the flat plate photovoltaic/thermal (PV/T) collector into four configurations (air-type, water-type, nanofuid-type and bi-fluid-type), according to the media used for operation. Benefits of using the different operation media were assessed and an optimum for high overall efficiency of the PV/T collector was achieved. Considering different variation trends in electrical and thermal efficiency of the PV/T collector, the effects of operation media, structural designs and climatic conditions on performances of flat plate PV/T collectors were discussed in consideration of relevant literature reports. Results demonstrated that the overall efficiency of a water-type PV/T collector was greater than an air-type PV/T collector, benefitting from the higher specific heat capacity of water yet with a complex structure. The nanofluid-type PV/T collector presented a higher overall efficiency than the others, due to the high thermal conductivity of dispersing nanoparticles in a base fluid and the colloidal stability of the nanofluid. Furthermore, the glass cover (with or without), absorber structure and relative location between the absorber and the fluid influenced the overall performance of the PV/T collector. In addition, the primary climatic conditions to influence performance were solar radiation and environmental temperature, with a dependence on the geographical installation region. Future studies were considered through progression of advanced PV/T technologies, when the PV/T collector could be integrated with residential and public buildings.

Design, optimization and performance analysis of an asymmetric concentrator-PV type window for the building south wall application

Article

Nov 2019
SOL ENERGY

The development of PV type window for building south wall integration is a promising concept, which provides a solution to the energy crisis and environment pollution problem. Thus in this paper, an asymmetric concentrator is proposed, and through the simple concentrator array optimization process, the asymmetric concentrator-PV type window can be designed, which provides the electricity generation and incorporates the function of daylighting at the same time. The optical models for the concentrator design and daylighting analysis are built and experimentally validated. The optical performance of the asymmetric concentrator has been analyzed. Considering that the incidence angles of sunrays on the building south wall remain at a high level throughout the year, the shading effect should be seriously considered. In order to reduce the shading effect between each concentrator array, the shading effect has been predicted and an arrangement optimization strategy by setting gaps between each concentrator array is presented. It was found that these gaps could alleviate the shading effect, which will also further allow the function of daylighting. Through the simulation analysis, it was found that the asymmetric concentrator can attain a large acceptance range of 10°–85° while maintaining high optical efficiency and the asymmetric concentrator-PV type window can achieve the daylighting efficiency of 4.0% to 21.8%, thus it can confirm good annual concentrating PV and daylighting performance. At last, a typical office room (the length, width and height are 3.4 m × 3.0 m × 3.3 m) installed with the asymmetric concentrator-PV type window is modelled and the illuminance distribution on the ground floor at various incidence angles is determined with the solar irradiance set at 500 W m⁻². Besides of that, the energy distribution for the electricity generation and daylighting at various incidence angles is also indicated. Through the analysis, the asymmetric concentrator-PV type window is proved suitable for building south wall integration, which can efficiently use the solar energy for the domestic use, in the forms of electricity and daylighting.

Experimental Investigation of a Novel Solar Micro-Channel Loop-Heat-Pipe Photovoltaic/Thermal (MC-LHP-PV/T) System for Heat and Power Generation

Article

Sep 2019
APPL ENERG

This paper aims to experimentally investigate a novel solar Micro-Channel Loop-Heat-Pipe Photovoltaic/Thermal (MC-LHP-PV/T) system which, making its first attempt to employ the co-axial tubular heat exchanger as the condenser, PV-bound multiple micro-channel tubes array as the PV/evaporator, the upper end liquid header with tiny holes as the liquid header and liquid/vapour separator, and the upper end vapour header as the vapour collector and distributor, can create the improved condensation and evaporation effects within the loop-heat-pipe (LHP) and thus, achieve significantly enhanced solar thermal and electrical efficiencies compared to traditional PV/T systems. Based on the results derived from our previous analytical study, a prototype MC-LHP-PV/T system employing R-134a as the working fluid was designed, constructed and tested, and the testing results were used to evaluate its operational performance including solar thermal and electrical efficiencies and their relevant impact factors. It is found that solar thermal efficiency of the MC-LHP-PV/T system varied with the inlet temperature and flow rate of coolant water, ambient temperature, as well as height difference between the condenser and evaporator. A lower inlet water temperature, a higher water flow rate, a higher ambient temperature, and a larger height difference between the condenser and the evaporator can help increase the solar thermal efficiency of the system. Under a range of testing conditions with the refrigerant charge ratio of 30%, a peak solar thermal efficiency (i.e., 71.67%) happened at solar radiation of 561W/m2, inlet water temperature of 18°C, water flow rate of 0.17m3/h, ambient temperature of 30°C, and height difference of 1.3m. This set of parametrical data is therefore regarded as the optimal operational condition of the MC-LHP-PV/T system. Under these specific operational condition and the real weather solar radiation, the solar thermal efficiency of the system was in the range 25.2% to 62.2%, while the solar electrical efficiency varied from 15.59% to 18.34%. Compared to the existing PV/T and BIPV/T systems, the new MC-LHP-PV/T system achieved 17.20% and 33.31% higher overall solar efficiency.

A general optimization strategy for the annual performance enhancement of a solar concentrating system incorporated in the south-facing wall of a building

Article

Sep 2019

A solar concentrating system incorporated to the south-facing wall could be a promising solution to alleviate the energy demand pressure in buildings. However, concentrating systems incorporated in south-facing walls would require wide acceptance range of concentrators with the purpose of static installation. In order to tackle this problem, this article proposes a novel unitary asymmetric concentrator structure for incorporating the concentrating system in the south-facing wall. A general optimization strategy for the annual performance enhancement of the concentrator is reported. Four kinds of concentrators were designed based on the proposed structure. The annual performance enhancement by this optimization strategy was analysed and compared through the ray-tracing simulation and experimental validation for four typical types of solar concentrators, i.e. Mirror Concentrator, Lens-Mirror Concentrator, Dielectric Concentrator and Air-Gap-Lens-Mirror Concentrator. The optical performance of these concentrators was studied and compared. Their application was analysed and validated through the analysis. The findings have illustrated the optical efficiency of the concentrators for concentrating the photovoltaics or photovoltaic-thermal system incorporated to the south-facing wall either by attachment or embedded into a building structure like a window. These concentrators can be engineered as the main component as a part of the design for a building.

Responsible Research and Innovation in Non- Formal Education Activities Related to Solar Energy Area

Conference Paper

Full-text available

Jan 2016

The results presented in this paper were acquainted in the context in which the technical progress and the speed of developments related to the use of nanomaterials in general, and into the solar energy applications in particular, imposed the Romanian school to harmonize the traditional training with the informal and non-formal ones, from the earliest school-age. In this respect, the authors, specialists in scientific research and education area, presented their contributions regarding the implementation of an innovative teaching layout structure dedicated to the non-formal training and using of solar energy, as proposed ideas to promote and disseminate the knowledge in the field. It is also illustrated the results of the demonstrative activities with students completed at the Workshops organized into the Scientific and Technological Institute of Multidisciplinary Research of Valahia University Targoviste, in the frame of the IRRESISTBLE Project, during the national week: "School-in Another Way". In this format, students made visits to the Research Institute, being informed on various applications of nanomaterials in renewable energy, having the possibility to perform practical application, using the experimental models with solar cells, results of collaboration between the university students and scientific researchers of the Institute. All those actions targeted to make known to young students, the concept of Responsible Research and Innovation in strong correlation to the paradigms of smart cities, energy efficiency and building integrated solar systems. Motto: "To me, the path to a sustainable energy future seems very obvious. We have to find a way to tap into a very small fraction of the sun's energy to convert it to a form suitable for supplying what are in fact the relatively small additional requirements of modern life. … I think the technological challenge can be met. It remains to be seen whether the political and organizational challenges involved in recognizing and addressing the need to change from the status quo can also be met on a reasonable timescale."

Numerical evaluation on energy saving potential of the photovoltaic fresh air preheating system in different climate regions of China

Article

May 2019
APPL THERM ENG

The fresh air system in buildings consumes a large amount of energy. To preheat fresh air by using solar energy can effectively reduce the energy consumption of buildings. This paper combines photovoltaic thermal system with air handling unit (AHU) fresh air system to supply buildings with fresh air, and the combined system utilizes photovoltaic (PV) cells to generate electricity while preheating the fresh air at the same time. Based on the control-volume method and zonal approach, a dynamic model suitable for simulating the PV fresh air preheating system in real operating conditions was developed in this paper. A PV fresh air preheating system test platform was set up and tested in Changsha. The model was validated by the data collected under real conditions and the simulated results show a good agreement with the experimental data. The performance of the PV fresh air preheating system and its energy saving potential in four typical cities in different climate regions, Changsha, Beijing, Shenyang and Lhasa respectively, were analyzed. Results show that the performance of the PV fresh air preheating system is mainly affected by the solar radiation. The application of the system in Lhasa can reach the highest energy saving potential among the researched cities, followed by Shenyang and Beijing. Due to the high ambient temperature and poor solar radiation, the monthly average total energy efficiency of Changsha is the lowest among the four cities. The results can provide a theoretical guidance for the application of the PV fresh air preheating system in different climate regions of China.

Improvement of Performances of Solar Photovoltaic/Thermal Air Collector in South Algeria

Conference Paper

Dec 2018

Cost-benefit analysis of integrating BIPV-T air systems into energy-efficient homes

Article

Oct 2016
SOL ENERGY

The market share of building-integrated photovoltaics (BIPV) remains limited. One of the main barriers to its larger adoption is its initial capital cost, as BIPV is generally more expensive than traditional roof or façade mounted photovoltaic modules (PV). Converting BIPV systems into BIPV with thermal energy recovery (BIPV-T) can improve its benefit and competitiveness compared to other solar energy technologies. This benefit is difficult to estimate, however, as it strongly depends on the usefulness of the thermal energy produced and the incremental cost of the technology to recover the heat. This study aims at evaluating the cost-benefit of BIPV-T focusing on systems that use air as the heat recovery fluid and are integrated into all-electric energy-efficient homes located in heating dominated climates. This cost-benefit is evaluated using the concept of break-even cost defined as the maximum incremental cost to convert a BIPV system into a BIPV-T system to break-even with the cost of (a) a BIPV system and (b) side-by-side PV modules and solar thermal collectors (PV + T). To obtain this cost, the useful equivalent energy production of BIPV, BIPV-T and PV + T systems was first obtained for six energy-efficient housing archetypes located in various cities across Canada. Four different heat management scenarios were considered for the BIPV-T system: (1) fresh air preheating, (2) domestic hot water preheating through an air-to-water heat exchanger, (3) domestic hot water and space heating with an air-to-water heat pump and (4) domestic hot water heating (DHW) with a heat pump water heater. Compared to BIPV, BIPV-T systems always produce more useful energy and as a result, the break-even cost compared to a BIPV system was found to be always positive and up to 2700 CAD for a medium 2-storey home located in Montreal. For that same house and considering the price of BIPV equal to that of standard roof-mounted PV modules, the break-even cost of a BIPVT system compared to a PV + T system was estimated at 4200 CAD. If the price of BIPV were to get 10% lower than PV, however, this break-even cost could increase to 6400 CAD.

Solar and wind induced external coefficients - Solar collectors

Article

Full-text available

May 1977

An examination is conducted of the wind coefficient commonly adopted for evaluations of the external heat transfer from the cover glasses of solar collectors subjected to a range of windspeeds. The wind coefficient, derived from McAdams (1954) and in turn from Jurges (1924), includes a radiation term. This inclusion of a radiation term in the wind coefficient implies that analysts of collector models may have doubly accounted for radiative heat transfer from the cover surface.

Comparative study of performance of four photovoltaic/thermal solar air collectors

Article

Full-text available

May 2000
ENERG CONVERS MANAGE

Adel Hegazy

An extensive investigation of the thermal, electrical, hydraulic and overall performances of flat plate photovoltaic/thermal (PV/T) air collectors has been made. Four popular designs are considered with the air flowing either over the absorber (Model I) or under it (Model II) and on both sides of the absorber in a single pass (Model III) or in a double pass fashion (Model IV). Heat balance equations are written for each model and are numerically solved, incorporating measured climate data. The effects of air specific flow rate and the selectivity of the absorber plate and PV cells on the performances have been examined. It is found that under similar operational conditions, the Model I collector has the lowest performance, while the other models exhibit comparable thermal and electrical output gains. Nevertheless, the Model III collector demands the least fan power, followed by Models IV and II. It is also shown that selective properties are inappropriate for these PV/T collectors due to the resultant reduction in the generated PV energy, especially at low flow rates. The study provides valuable information regarding the design and operation of such types of PV/T air collectors.

Performance and cost of a roof-sized PV/thermal array combined with a ground coupled heat pump

Article

Full-text available

Nov 2004
SOL ENERGY

A photovoltaic/thermal (PVT) panel is a combination of photovoltaic cells with a solar thermal collector, generating solar electricity and solar heat simultaneously. Hence, PVT panels are an alternative for a combination of separate PV panels and solar thermal collectors. A promising system concept, consisting of 25 m2 of PVT panels and a ground coupled heat pump, has been simulated in TRNSYS. It has been found that this system is able to cover 100% of the total heat demand for a typical newly-built Dutch one-family dwelling, while covering nearly all of its own electricity use and keeping the long-term average ground temperature constant.The cost of such a system has been compared to the cost of a reference system, where the PVT panels have been replaced with separate PV panels (26 m2) and solar thermal collectors (7 m2), but which is otherwise identical. The electrical and thermal yield of this reference system is equal to that of the PVT system. It has been found that both systems require a nearly identical initial investment.Finally, a view on future PVT markets is given. In general, the residential market is by far the most promising market. The system discussed in this paper is expected to be most successful in newly-built low-energy housing concepts.

Chapter 225. Studies on Cost Effectiveness of Hybrid Photovoltaic/Thermal (PV/T) Air Heating Collector

Chapter

Dec 2000

This chapter discusses the studies on cost effectiveness of hybrid photovoltaic /thermal air heating collector. This chapter a techno-economic analysis of a single hybrid PV/T air heating collector. Various energy balance equations have been developed for evaluating the useful thermal and electrical energy gain. The economic analysis takes in to account the capital costs, maintenance costs, operating costs, useful life of the system, interest rate etc. Numerical calculations have been made to optimize different design parameters for a given system and climatic parameters. Among various application of solar energy, hybrid photovoltaic/thermal (PV/T) energy conversion is relatively new and promising technology for the production of both thermal and electrical energy simultaneously. The chapter also presents a techno-economic analysis for a hybrid P V/T air heating collector. The economic analysis takes in to account the capital costs, maintenance costs, operating costs, useful life of the system and interest rate etc. Numerical calculations have been made to optimize different design parameters, for example, collector length, duct depth, solar cell area etc. for a given system and climatic parameters. The study is limited to cost effectiveness studies on single glass cover photovoltaic or thermal air heating collector, which supplies hot air and electricity directly.

Solar Technologies for Buildings

Book

Sep 2005

Ursula Eicker

A complete overview of solar technologies relevant to the built environment, including solar thermal energy for heating and cooling, passive solar energy for daylighting and heating supply, and photovoltaics for electricity production. Provides practical examples and calculations to enable component and system simulation e.g. Calculation of U-values, I-V curve parameters and radiance distribution modelling. Discusses the new trends in thermal energy use, including the architectural integration of collector systems, integrated ventilation photovoltaics facades and solar powered absorption cooling systems. Coverage of cutting-edge applications such as active and passive cooling techniques and results from ongoing research projects.

Experimental Study to Characterize the Performance of Combined Photovoltaic/Thermal Air Collectors

Article

Aug 2012
J SOL ENERG-T ASME

Combined photovoltaic/thermal (PV/T) collectors show great potential for reaching the objective of net-zero energy consumption in buildings, but the number of products on the market is still very limited. One of the reasons for the slow market uptake of PV/T collectors is the absence of standardized methods to characterize their performance. Performance characterization is a challenge for PV/T collectors because of the interaction between the thermal and electrical yield. This study addresses this particular issue for PV/T air collectors used in either closed-loop or open-loop configurations. In particular, it presents the potential of the equivalent cell temperature method to determine the temperature of the PV cells in a PV/T air collector and validates models to predict the thermal performance and cell temperature for this particular type of solar collector. Indoor and outdoor experimental tests were performed on two c-Si unglazed PV/T modules. The indoor part of this procedure provided the thermal diode voltage factor and the open-circuit voltage temperature coefficient, two parameters that are essential in the calculation of the equivalent cell temperature. The outdoor procedure consisted of acquiring simultaneous electrical and thermal measurements at various inlet temperatures and flowrates. For the collector used in a closed-loop configuration, thermal efficiency models using the fluid inlet, outlet, or average temperature in the calculation of the reduced temperature provided similar results. For an open-loop configuration, a thermal efficiency model as a function of the fluid outlet flowrate was found to be more appropriate. Using selection of variable methods, it was found that a multiple linear regression model using the fluid inlet temperature, the irradiance, and the fluid outlet temperature as predictive variables could be used to estimate both the PV module back surface average temperature and the equivalent cell temperature. When using the PV temperature predicted by these models in the electrical efficiency model, both PV temperatures showed similar performance. In collectors where the PV back surface temperature is not accessible for temperature sensors mounting, the equivalent cell temperature provides a valuable alternative to be used as the PV temperature. The PV/T collector thermal and electrical performance in either closed-loop or open-loop configurations was found to be encapsulated with a series of five-plots. [DOI: 10.1115/1.4006576]

Convective Heat Transfer Coefficients in a Building-Integrated Photovoltaic/Thermal System

Article

May 2011
J SOL ENERG-T ASME

This paper presents an experimental study for the development of convective heat transfer correlations for an open loop air-based building-integrated photovoltaic/thermal (BIPV/T) system. The BIPV/T system absorbs solar energy on the top surface, which includes the photovoltaic panels and generates electricity while also heating air drawn by a variable speed fan through a channel formed by the top roof surface with the photovoltaic modules and an insulated attic layer. The BIPV/T system channel has a length/hydraulic diameter ratio of 38, which is representative of a BIPV/T roof system for 30-45 deg tilt angles. Because of the heating asymmetry in the BIPV/T channel, two average Nusselt number correlations are reported as a function of Reynolds number: one for the top heated surface and the other for the bottom surface. For the top heated surface, the Nusselt number is in the range of 6-48 for Reynolds numbers ranging from 250 to 7500. For the bottom insulated surface, the Nusselt number is in the range of 22-68 for Reynolds numbers ranging from 800 to 7060. This paper presents correlations for the average Nusselt number as a function of Reynolds number; this correlation is considered adequate for the design of BIPV/T systems where forced convection dominates. Local Nusselt number distributions are also presented for laminar and turbulent flow conditions. [DOI: 10.1115/1.4003145]

Fundamental of Heat and Mass Transfer

Book

Jan 1996

A prototype photovoltaic/thermal system integrated with transpired collector

Article

Jan 2011
SOL ENERGY

Building-integrated photovoltaic/thermal (BIPV/T) systems may be utilized to produce useful heat while simultaneously generating electricity from the same building envelope surface. A well known highly efficient collector is the open-loop unglazed transpired collector (UTC) which consists of dark porous cladding through which outdoor air is drawn and heated by absorbed solar radiation. Commercially available photovoltaic systems typically produce electricity with efficiencies up to about 18%. Thus, it is beneficial to obtain much of the normally wasted heat from the systems, possibly by combining UTC with photovoltaics. Combination of BIPV/T and UTC systems for building facades is considered in this paper - specifically, the design of a prototype facade-integrated photovoltaic/thermal system with transpired collector (BIPV/T). A full scale prototype is constructed with 70% of UTC area covered with PV modules specially designed to enhance heat recovery and compared to a UTC of the same area under outdoor sunny conditions with low wind. The orientation of the corrugations in the UTC is horizontal and the black-framed modules are attached so as to facilitate flow into the UTC plenum. While the overall combined thermal efficiency of the UTC is higher than that of the BIPV/T system, the value of the generated energy - assuming that electricity is at least four times more valuable than heat - is between 7% and 17% higher. Also, the electricity is always useful while the heat is usually utilized only in the heating season. The BIPV/T concept is applied to a full scale office building demonstration project in Montreal, Canada. The ratio of photovoltaic area coverage of the UTC may be selected based on the fresh air heating needs of the building, the value of the electricity generated and the available building surfaces. (author)

Effect of Finite Width on Heat Transfer and Fluid Flow about an Inclined Rectangular Plate

Article

May 1979
J HEAT TRANS-T ASME

Wind tunnel experiments were performed to study the heat transfer and fluid flow characteristics for finite-width rectangular plates inclined at various angles of attack to an oncoming airflow. Plates having ratios of spanwise width to streamwise length of 0.4 and 2.5 were employed, and the angle of attack was varied from 90 deg to 25 deg. The Reynolds number range extended from about 20,000 to 90,000. The naphthalene sublimation technique was used in the transfer coefficient determinations, and the fluid flow patterns adjacent to the plate were made visible by the oil/lampblack technique. The flow field was found to be highly complex and three dimensional, with stronger three-dimensional effects in evidence for the narrow plate. A stagnation zone, centered in the plate cross section at normal incidence, moved forward and ultimately disappeared as the plate was inclined at smaller angles of attack. The dimensionless heat (mass) transfer coefficient, expressed in terms of the Colburn j-factor, varied as the square root of the Reynolds number for all angles of attack, both for the narrow and the wider plates.

Heat Transfer During Wind Flow over Rectangular Bodies in the Natural Environment

Article

May 1981
J HEAT TRANS-T ASME

An experimental investigation has been performed to determine the constant temperature heat transfer behavior on the upper surface of a rectangular plate with a chord length of 122 cm, a width of 81. 3 cm and a thickness aspect ratio of 6/1. Special side attachments were made to maintain approximately two-dimensional flow over the finite width body when exposed to varying wind directions. The angle of attack was 40 deg or greater. The disturbance intensity of the wind flow was in the range of 20 to 50 percent and is thought to be related to the increase in heat transfer since the flow over the plate was found to be laminar.

Modelling of a double-glass photovoltaic module using finite differences

Article

Dec 2005
APPL THERM ENG

A simulation model of finite differences describing a double-glass multi-crystalline photovoltaic module has been developed and validated using experimental data from such a photovoltaic module. This simulation model is based on various thermal hypotheses, particularly concerning the convective transfer coefficients: thus, various hypotheses found in the literature have been tested and the best one has been accepted. Using this modelling procedure, the cell temperature is estimated with a root mean square error of 1.3°C.

The influence of PV coverage ratio on thermal and electrical performance of photovoltaic-Trombe wall

Article

Nov 2008
RENEW ENERG

This paper presents a novel photovoltaic-Trombe wall (PV-TW). Based on the actual measured weather data in Hefei, a detailed simulation model for PV-TW is presented. The simulation results show that as the coverage ratio increases, the electrical yield and the total efficiency of PV-TW increases, but the indoor temperature and the thermal efficiency of PV-TW decreases. The maximum indoor air temperature difference, corresponding to the lowest and the highest coverage ratio, can reach to 6.8°C above. In addition, as the coverage ratio increases, the electrical efficiency of photovoltaic cell decreases, but the influence of coverage ratio on electrical efficiency is slight, less than 0.5%.

Heat Transfer in Automobile Radiators of the Tubular Type

Article

Feb 1985
INT COMMUN HEAT MASS

Performance studies on a finned double-pass photovoltaic-thermal (PV/T) solar collector

Article

Apr 2007
DESALINATION

A hybrid photovoltaic–thermal (PV/T) solar air heater system which generates both electricity and heat energy simultaneously was studied. Mathematical model and test results are presented. This hybrid system consists of monocrystalline silicon cells pasted to an absorber plate with fins attached at the other side of the absorber surface. Air as heat removing fluid is made to flow through an upper channel and then under the absorber plate or lower channel of the collector. Only a small part of the absorbed solar radiation is converted to electricity, while the rest increases the temperature of the cells. Improvements to the total efficiency of the system can be achieved by the use of a double-pass collector system and fins. It gives more interesting hybrid photovoltaic-thermal system design for practical applications.

Hybrid photovoltaic/thermal (PV/T) solar systems simulation with Simulink/Matlab

Article

Dec 2010
SOL ENERGY

Wind heat transfer coefficient in solar collectors in outdoor conditions

Article

Jun 2010
SOL ENERGY

Knowledge of wind heat transfer coefficient, hw, is required for estimation of upward losses from the outer surface of flat plate solar collectors/solar cookers. In present study, an attempt has been made to estimate the wind induced convective heat transfer coefficient by employing unglazed test plate (of size about 0.9 m square) in outdoor conditions. Experiments, for measurement of hw, have been conducted on rooftop of a building in the Institute campus in summer season for 2 years. The estimated wind heat transfer coefficient has been correlated against wind speed by linear regression and power regression. Experimental values of wind heat transfer coefficient estimated in present work have been compared with studies of other researchers after normalizing for plate length.

A survey of wind convection coefficient correlations for building envelope energy systems’ modeling

Article

Jun 2008

J.A. Palyvos

The thermal losses to the ambient from a building surface or a roof mounted solar collector represent an important portion of the overall energy balance and depend heavily on the wind induced convection. In an effort to help designers make better use of the available correlations in the literature for the external convection coefficients due to the wind, a critical discussion and a suitable tabulation is presented, on the basis of algebraic form of the coefficients and their dependence upon characteristic length and wind direction, in addition to wind speed. Finally, simple average correlations are produced from the existing ones, useful for quick, gross estimates.

The convective heat exchange at the external surface of buildings

Article

Dec 1977
BUILD ENVIRON

The relationships currently used to describe the convective heat exchanges at the external surfaces of buildings are based on wind tunnel measurements undertaken over 40 years ago. Recent field measurements have disclosed inadequacies in the application of this early work. This paper provides a review of the nature of convective heat exchanges and discusses the various relationships which have been presented in the literature to describe it.

Energy and exergy analysis of photovoltaic–thermal collector with and without glass cover

Article

Mar 2009
APPL ENERG

In photovoltaic–thermal (PV/T) technology, the use of glass cover on the flat-plate hybrid solar collector is favorable to the photothermic process but not to the photovoltaic process. Because of the difference in the usefulness of electricity and thermal energy, there is often no straight forward answer on whether a glazed or unglazed collector system is more suitable for a specific application. This glazing issue was tackled in this paper from the viewpoint of thermodynamics. Based on experimental data and validated numerical models, a study of the appropriateness of glass cover on a thermosyphon-based water-heating PV/T system was carried out. The influences of six selected operating parameters were evaluated. From the first law point of view, a glazed PV/T system is found always suitable if we are to maximize the quantity of either the thermal or the overall energy output. From the exergy analysis point of view however, the increase of PV cell efficiency, packing factor, water mass to collector area ratio, and wind velocity are found favorable to go for an unglazed system, whereas the increase of on-site solar radiation and ambient temperature are favorable for a glazed system.

Performance of double pass photovoltaic thermal solar collector suitable for solar drying systems

Article

Mar 2000
ENERG CONVERS MANAGE

The photovoltaic thermal solar collector, sometimes known as the hybrid solar collector generates both thermal and electrical energies simultaneously. A double pass photovoltaic thermal solar collector suitable for solar drying applications has been developed and tested. A steady state closed form solution to determine the outlet and mean photovoltaic panel temperature has been obtained for the differential equations of the upper and lower channels of the collector. Hence, the photovoltaic, thermal and combined photovoltaic thermal efficiencies can be obtained. An experimental setup has been developed. For given sets of operating and design conditions the theoretical and experimental outlet and mean photovoltaic panel temperatures can be obtained. Comparisons are made between the experimental and theoretical results and close agreement between these two values are obtained.

An experimental study on energy generation with a photovoltaic (PV)–solar thermal hybrid system

Article

Aug 2008
ENERGY

A hybrid system, composed of a photovoltaic (PV) module and a solar thermal collector is constructed and tested for energy collection at a geographic location of Cyprus. Normally, it is required to install a PV system occupying an area of about 10 m2 in order to produce electrical energy; 7 kWh/day, required by a typical household. In this experimental study, we used only two PV modules of area approximately 0.6 m2 (i.e., 1.3×0.47 m2) each. PV modules absorb a considerable amount of solar radiation that generate undesirable heat. This thermal energy, however, may be utilized in water pre-heating applications. The proposed hybrid system produces about 2.8 kWh thermal energy daily. Various attachments that are placed over the hybrid modules lead to a total of 11.5% loss in electrical energy generation. This loss, however, represents only 1% of the 7 kWh energy that is consumed by a typical household in northern Cyprus. The pay-back period for the modification is less than 2 years. The low investment cost and the relatively short pay-back period make this hybrid system economically attractive.

Residential cogeneration systems: Review of the current technology

Article

Oct 2006
RENEW SUST ENERG REV

There is a growing potential for the use of micro-cogeneration systems in the residential sector because they have the ability to produce both useful thermal energy and electricity from a single source of fuel such as oil or natural gas. In cogeneration systems, the efficiency of energy conversion increases to over 80% as compared to an average of 30–35% for conventional fossil fuel fired electricity generation systems. This increase in energy efficiency can result in lower costs and reduction in greenhouse gas emissions when compared to the conventional methods of generating heat and electricity separately.Cogeneration systems and equipment suitable for residential and small-scale commercial applications like hospitals, hotels or institutional buildings are available, and many new systems are under development. These products are used or aimed for meeting the electrical and thermal demands of a building for space and domestic hot water heating, and potentially, absorption cooling.The aim of this paper is to provide an up-to-date review of the various cogeneration technologies suitable for residential applications. The paper considers the various technologies available and under development for residential, i.e. single-family (<10 kWe) and multi-family (10–30 kWt) applications, with focus on single-family applications. Technologies suitable for residential cogeneration systems include reciprocating internal combustion engine, micro-turbine, fuel cell, and reciprocating external combustion Stirling engine based cogeneration systems. The paper discusses the state of development and the performance, environmental benefits, and costs of these technologies.

The absorption factor of crystalline silicon PV cells: A numerical and experimental study

Article

Apr 2008
SOL ENERG MAT SOL C

The absorption factor of a PV cell is defined as the fraction of incident solar irradiance that is absorbed by the cell. This absorption factor is one of the major parameters determining the cell temperature under operational conditions. Experimentally the absorption factor can be derived from reflection and transmission measurements. The spectral reflection and transmission factors were measured for a set of crystalline silicon (c-Si) samples with a gradually increasing complexity. The experimental results agree very well with the results from a 2D numerical model that was developed. It was found that the AM1.5 absorption factor of a typical encapsulated c-Si photovoltaic cell is as high as 90.5%. Insight was gained in the cell parameters that influence this absorption factor. The presence of texture at the front of the c-Si wafer of sufficient steepness is essential to achieve such a high absorption factor. Sub-bandgap solar irradiance is mainly absorbed in the very thin emitter by means of free-carrier absorption. By minimizing reflective losses over the entire solar spectrum, the AM1.5 absorption of c-Si cells can theoretically be increased to 93.0%. The effect on the annual yield of PV and PV/thermal systems is quantified.

Full-scale measurements of wind-induced: Convective heat transfer from a roof mounted flat plate solar collector

Article

Feb 1998
SOL ENERGY

A series of full-scale measurements in the real environment were made to assess the magnitude and variability of wind-induced convective heat transfer from a raised heated surface mounted directly on to the pitched roof of a domestic size building. The heated plate had dimensions similar to those of a typical flat-plate solar collector (1.81×0.89 m2), giving a Reynolds number range of approximately 1×105 to 5×105. The measured forced convective heat transfer coefficient hw was correlated against the wind speed V and the wind direction prevailing at the site of the building during the periods of measurement. For a range of wind directions it was found that both power and linear relationships between hw and V adequately represented the experimental results. Some sheltering effects were observed when the heated plate was leeward to the prevailing wind direction. Values of hw measured in this study were in good agreement with data derived from previous wind tunnel and field work.

Parametric study of various configurations of hybrid PV/thermal air collector: Experimental validation of theoretical model

Article

Jan 2007
SOL ENERG MAT SOL C

In this paper, an attempt has been made to evaluate the overall performance of hybrid PV/thermal (PV/T) air collector. The different configurations of hybrid air collectors which are considered as unglazed and glazed PV/T air heaters, with and without tedlar. Analytical expressions for the temperatures of solar cells, back surface of the module, outlet air and the rate of extraction of useful thermal energy from hybrid PV/T air collectors have been derived. Further an analytical expression similar to Hottel–Whiller–Bliss (HWB) equation for flat plate collector has also been derived in terms of design and climatic parameters. Numerical computations have been carried out for composite climate of New Delhi and the results for different configurations have been compared. The thermal model for unglazed PV/T air heating system has also been validated experimentally for summer climatic conditions. It is observed that glazed hybrid PV/T without tedlar gives the best performance.

Performance evaluation of solar photovoltaic/thermal systems

Article

Dec 2001
SOL ENERGY

The major purpose of the present study is to understand the performance of an integrated photovoltaic and thermal solar system (IPVTS) as compared to a conventional solar water heater and to demonstrate the idea of an IPVTS design. A commercial polycrystalline PV module is used for making a PV/T collector. The PV/T collector is used to build an IPVTS. The test results show that the solar PV/T collector made from a corrugated polycarbonate panel can obtain a good thermal efficiency. The present study introduces the concept of primary-energy saving efficiency for the evaluation of a PV/T system. The primary-energy saving efficiency of the present IPVTS exceeds 0.60. This is higher than for a pure solar hot water heater or a pure PV system. The characteristic daily efficiency ηs* reaches 0.38 which is about 76% of the value for a conventional solar hot water heater using glazed collectors (ηs*=0.50). The performance of a PV/T collector can be improved if the heat-collecting plate, the PV cells and the glass cover are directly packed together to form a glazed collector. The manufacturing cost of the PV/T collector and the system cost of the IPVTS can also be reduced. The present study shows that the idea of IPVTS is economically feasible too.

Conventional hybrid photovoltaic/thermal (PV/T) air heating collectors: Steady-state simulation

Article

Jul 1997
RENEW ENERG

This investigation is concerned with the performance analysis of a conventional hybrid photovoltaic/thermal air heating collector. A simulation model is developed and various performance parameters are calculated for single-glass and double-glass configurations. Results are presented to show the effect of various design and operational parameters on the performance of a system. These results are useful for designing such systems more scientifically. However, final selection of design and operational variables must be based on the cost-effectiveness of the system.

Development of an approach to compare the ‘value’ of electric and thermal output from domestic PV/thermal system

Article

Jul 2003
SOL ENERGY

When considering the design of a PV/thermal system, determination of the ratio of the values of the electrical and thermal output from the system allows a rational approach to design optimisation via the minimization of ‘equivalent electrical levelised energy cost’. This paper focuses on methods that can be employed to develop a ratio between electrical and thermal output from a domestic style PV/thermal system. Methods discussed include thermodynamic analysis using exergy; market analysis for both an open market and a renewable energy market; and environmental analysis using avoided greenhouse gas emissions. Ratios are developed for each method based on real data. It is concluded that a renewable energy market approach seems most logical for such a system, and an indicative value of 4.24 is obtained. An example is given comparing a PV/thermal system that uses amorphous silicon cells with one that uses crystalline silicon cells. Levelised energy cost is plotted against the energy value ratio to show that there is a critical electrical-to-thermal energy value ratio below which a collector with a-Si cells is more cost effective than one with c-Si cells.

Survey of Active Solar Thermal Collectors <http://solarthermal-world.org/sites/gstec/files/survey of active solar thermal collectors

Jan 1985

Clearsky Inc

ClearSky Advisors Inc., 2012. Survey of Active Solar Thermal Collectors, Industry and Markets in Canada (2011). <http://solarthermal-world.org/sites/gstec/files/survey of active solar thermal collectors 2012> August.pdf. da Silva, R.M., Fernandes, J.L.M., 2010. Hybrid photovoltaic/thermal (PV/T) solar systems simulation with Simulink/Matalb. Solar Energy 84, 1985–1996.

Photovoltaic (PV) Module Performance Testing and Energy Rating – Part 1: Irradiance and Temperature Performance Measurements and Power rating. IEC 61853-1, International Electrotechnical Commission A TRaNsient SYstem Simulation Program – User Manual, Version 17

Jan 2009

Klein

International Electrotechnical Commission (IEC), 2011. Photovoltaic (PV) Module Performance Testing and Energy Rating – Part 1: Irradiance and Temperature Performance Measurements and Power rating. IEC 61853-1, International Electrotechnical Commission. Klein et al., 2009. A TRaNsient SYstem Simulation Program – User Manual, Version 17. University of Wisconsin-Madison, USA.

Building Integrated Photovoltaics – BIPV and BAPV: Market Drivers and Challenges, Technology Issues, Compet-itive Landscape, and Global Market ForecastsNavigant biPV report

Jan 2012

Pikeresearch

PikeResearch, 2012. Building Integrated Photovoltaics – BIPV and BAPV: Market Drivers and Challenges, Technology Issues, Compet-itive Landscape, and Global Market ForecastsNavigant biPV report, Boulder.

RS Means Building Construction Cost Data

Jan 2013

R S Means

Means, R.S., 2013a. RS Means Building Construction Cost Data. Reed Construction Data Inc., United States.

A novel approach to compare building-integrated photovoltaics/thermal air collectors to side-by-side PV modules and solar thermal collectors

Abstract

No full-text available

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