SOLAR AND BIOMASS FOR ITALIAN COMMUNITIES: ANALYSIS OF TWO CASE STUDIES
Abstract and Figures
In the frame of SmartReFlex project, smart and flexible 100% renewable district heating and cooling systems are promoted thanks to the analysis of local case studies. Italian partners are assessing the feasibility of this kind of projects in the region of Emilia Romagna, supporting local communities willing to go for renewables. In this work, two case studies dealing with existing DH extensions powered by biomass and solar thermal are analysed. Alternative solutions are assessed in terms of energy performances, economic sustainability and environmental impact. Results show biomass can definitely decrease the CO2 emissions but increases the pollutant emissions that can definitely be reduced by solar thermal.
Figures - uploaded by Alice Denarie
Author content
All figure content in this area was uploaded by Alice Denarie
Content may be subject to copyright.
... Such performances have been quantified through simulations of future possible alternatives with energy PRO, a simulation software for technical and economic analyses (EMD 2014). A model of the current configuration of district heating with cogeneration systems, including Italian electricity market interaction, has been built and validated through monitoring data (Dénarié et al. 2016). The validated model has been used to simulate four configurations of various types of renewable-energy integrations for the extension of the system (Fig. 3). ...
... The four alternatives have been simulated in order to calculate the energy, environmental and economic results. Details of the simulation's input data and hypothesis can be found in Dénarié et al. (2016). Figures 4 and 5 show the four alternatives' energy production, environmental impact and cash flow resulting from investment costs, operational costs, revenues and incentives. ...
... The performance matrix of the four alternatives is presented in Table 1. Details of calculation are in Dénarié et al. (2016). The need to deal with the problem of finding the best alternative with MCDA techniques is clearly demonstrated by the fact that the best alternative is not always the same, when based on different criteria. ...
The EU project SmartReFlex—smart and flexible, 100%-renewable district heating and cooling systems for European cities—aims to promote the massive use of renewable sources for heating and cooling in cities through district heating networks. Among the project activities, the analysis of real case studies shows the potential of renewables in district heating systems. AIRU, Italian Association of District Heating, and the Department of Energy of Politecnico di Milano are supporting the promotion of local initiatives for renewable networks in the Emilia Romagna region: the feasibility of a multisource DHC system in Mirandola is assessed and presented in this paper. In Mirandola’s district heating and cooling system, natural gas is only one among several possible energy sources: alternative configurations integrating biomass, biogas and solar thermal have been included in the study. The analysis deals with the extension of the network and with the choice of the best new energy source to cover the new heat demand. The use of MCDA has been applied in order to perform a holistic analysis of possible energy-related choices by considering competing objectives. For instance, the use of biomass is quite controversial: biomass is a renewable, local and a CO2 neutral source, able to reduce GHG emissions. However, biomass burning can have negative impacts on air quality by producing pollutants such as PM10, BaP, SOx and NOx. This paper presents the multicriteria process applied to plant design, the various alternatives and the criteria used. The result is a combination of natural gas, biogas, solar thermal energy and biomass, which corresponds to the preference of both the utility and municipality.
... The viability of large heat pumps in existing district heating systems has been examined also in Finland, in the study at Ref. [10], where the feasible share of heat pump production has been quantified by simulating different sized DH systems with energyPRO. This software has been used in a variety of other European case studies aimed at transitioning towards more sustainable and less-emissive energy systems, as in [11] where the replacement of coal boilers with natural gas boilers has been validated, and in several studies finalized in promoting the integration in existing district heating networks of renewable sources, such as biomass and solar thermal technologies in combination with large scale heat pumps [12][13][14][15], and of excess heat sources, such a local refinery [16], datacentres [17], waste-to-energy plants [18]. In this latter paper, also the integration of heat storages is considered, which allows the peak shaving effect: the required installed capacity is reduced, together with the related needs for investment in peaking capacities. ...
The process of achieving decarbonization and greenhouse emissions’ reduction goals is facilitated and accelerated by the implementation of renewable-based DH rather than multiple individual renewables systems. This work presents an application case that demonstrates how an energy system based on conventional and carbon-emitting heat supply sources can be converted in a fully renewable network.
In its current configuration, the city under study, located in Northern Italy, gets 40% of the total 160GWh of heat demand of the DH from a waste-to-energy plant, 9% from a biomass-fuelled ORC, 33% from natural gas cogeneration and 18% from natural gas boilers. In order to support the city’s municipality in developing decarbonization measures through the modernization of the current district heating network, the aim of this work is to investigate in detail the possibility to integrate local renewable and excess heat sources, whose availability and synergy with the heat demand has been highlighted by a recent mapping-based project developed with the Italian DH Association, AIRU, on the whole Italian territory. The present work can be therefore seen as a validation case study of the methodology developed at large-scale level in the latter project. The results of that analysis show that there are the conditions to meet 90% of the heating needs of the DH with renewables and waste heat recovery from two already existing plants, namely a wastewater treatment plant (WWTP) and a steelwork. The approach used in this work, in which different scenarios of integration are simulated in energyPRO, brought to the definition of the energy mix which evidenced a favourable cost–benefits ratio: 59% of thermal energy from the steelwork, 31% from the WWTP, 5% from the natural gas CHP and 5% from the boilers.
This paper includes a review of the different computer tools that can be used to analyse the integration of renewable energy. Initially 68 tools were considered, but 37 were included in the final analysis which was carried out in collaboration with the tool developers or recommended points of contact. The results in this paper provide the information necessary to identify a suitable energy tool for analysing the integration of renewable energy into various energy-systems under different objectives. It is evident from this paper that there is no energy tool that addresses all issues related to integrating renewable energy, but instead the ‘ideal’ energy tool is highly dependent on the specific objectives that must be fulfilled. The typical applications for the 37 tools reviewed (from analysing single-building systems to national energy-systems), combined with numerous other factors such as the energy-sectors considered, technologies accounted for, time parameters used, tool availability, and previous studies, will alter the perception of the ‘ideal’ energy tool. In conclusion, this paper provides the information necessary to direct the decision-maker towards a suitable energy tool for an analysis that must be completed.
District heating (DH) enables the utilisation and distribution of heating from sources unfeasible for stand-alone applications and combined with cogeneration of heat and power (CHP), has been the cornerstone of Denmark’s realisation of a steady national primary energy supply over the last four decades. However, progressively more energy-efficient houses and a steadily improving heat pump (HP) performance for individual dwellings is straining the competitive advantage of the CHP–DH combination as DH grid losses are growing in relative terms due to decreasing heating demands of buildings and relatively high DH supply temperatures.
This paper considers the composition of the daily heat load in six Swedish district heating systems supplying heat for space heating and hot water supply. The analysis is performed by bringing together a heat load model and series of daily heat load observations covering periods ranging from 5 to 11 years. The model takes into account temperature-dependent heat losses due to transmission and ventilation, transient heat transmission, solar gain, wind-induced air infiltration, hot water supply, heat losses in the distribution network, and additional workday load.
The Swedish energy system is undergoing a transformation due to threats about climate change and political decisions to reduce green house gases and to phase out the nuclear power. The goal is to convert the energy system from a system based on fossil fuels and nuclear power to one based on renewable energy sources. Bioenergy is an available domestic, renewable, carbon dioxide neutral energy source and therefore an increase of the use is forecasted in the future. Studies have shown that bioenergy may cause negative impacts on human health and on the environment due to emissions to air. The aim of this study was to investigate how a future conversion to bioenergy-based heating affect the air quality in residential areas. The contribution of particulate matter (PM10) and benzene from existing heating systems as well as from conversion from electrical heating and firewood boilers to pellets and small-scale district heating systems was investigated. The investigations included monitoring of energy need for heating, identifying suitable energy systems for conversion, identifying emission factors, dispersion calculations and application of the results in a geographical information system (GIS). The results show that conversion from electrical heating to pellets in the investigated areas does not affect the air quality. The GIS maps showed the expected concentrations caused by small-scale combustion of bioenergy-based fuels clearly. The dispersion pattern of the emitted gases and particulates was visualized and the maps can be used for planning purposes when dealing with new residential areas.
In this paper, starting from previous works, further analyses on district heating cogeneration systems are proposed and particular attention is given to the NOx pollutant. In addition to the mean yearly concentrations, the hourly limit values for the protection of human health are also taken into account: the 18th maximum hourly concentration is considered. The main steps necessary to characterize a district heating plant are shown and two case-studies are discussed. As far as the energetic aspects are concerned, these new plants always offer a primary energy saving, and the global environmental effects are improved due to a reduction in CO2. Local NOx emissions of a future plant do not decrease with respect to the existing emissions, and this aspect is closely connected to the type of CHP unit that is adopted (in this paper, natural gas fuelled engines). The local environmental effects due to NOx are estimated using a dispersion model, and the NOx concentrations (annual mean value and maximum hourly value) introduced by the new plant and those avoided through the non-use of existing domestic boilers are compared. For one of the case-studies emerges that some zones do not satisfy ambient air quality limits. For these reasons, a higher stack has been assumed for this critical case and the new results show that a reduction in the frequency of the overcomings, which is in agreement with expectations, can thus be obtained. The analysed case-studies have shown that even a small CHP district heating plant can produce critical aspects and a pollutant concentration analysis is a useful tool to check local environmental aspects.
Measurement of Domestic Hot Water Consumption in Dwellings, report for Department for Environment Food & Rural Affairs of UK Government EU Commission Staff Working Document, Guidance note on Directive 2012
EST (2008) Measurement of Domestic Hot Water
Consumption in Dwellings, report for Department for
Environment Food & Rural Affairs of UK Government
EU Commission Staff Working Document, Guidance
note on Directive 2012/27/EU on energy efficiency
UP-RESProject (2011), M6 – Energy Distribution:
District Heating and Cooling
Heating technologies for limiting biomass consumption in 100% renewable energy systems. Paper presented at 6th Dubrovnik Conference on Sustainable Development of Energy, Water and Environment Systems, Dubrovnik, Croatia Nielsen J. E (2014) A Booming Market for Solar District Heating
- B V Mathiesen
Mathiesen, B. V. et al (2011). Heating technologies for
limiting biomass consumption in 100% renewable energy
systems. Paper presented at 6th Dubrovnik Conference
on Sustainable Development of Energy, Water and
Environment Systems, Dubrovnik, Croatia
Nielsen J. E (2014) A Booming Market for Solar District
Heating, Proceedings of SHC Conference 2014, 13-15
res-hc-spread.eu AEEGSI (2015) Relazione annuale sullo stato dei servizi e sull
- Arpa Er
ARPA ER, www.res-hc-spread.eu
AEEGSI (2015). Relazione annuale sullo stato dei servizi
e sull'attività svolta 2015
A Booming Market for Solar District Heating
- J E Nielsen
Nielsen J. E (2014) A Booming Market for Solar District
Heating, Proceedings of SHC Conference 2014, 13-15
Measurement of Domestic Hot Water Consumption in Dwellings, report for Department for Environment Food & Rural Affairs of UK Government EU Commission Staff Working Document
- S Werner
Werner S. (1984) The heat load in district heating
systems. Doctoral thesis. Department of Energy
Conversion, Chalmers University of Technology,
Gothenburg.
EST (2008) Measurement of Domestic Hot Water
Consumption in Dwellings, report for Department for
Environment Food & Rural Affairs of UK Government
EU Commission Staff Working Document, Guidance
note on Directive 2012/27/EU on energy efficiency
UP-RESProject (2011), M6 -Energy Distribution:
District Heating and Cooling