Wilfried Zörner

Technische Hochschule Ingolstadt · Faculty of Mechanical Engineering

Small-scale biogas systems hold promise as reliable renewable energy sources in developing nations; however, adequate and consistent supply of feedstock remains a challenge. Agricultural residue, due to their lack of competition with food crops for resources, is touted as a dependable feedstock choice. This article therefore examines agricultural r...

Sub-Saharan Africa, especially its rural areas, faces significant challenges in achieving universal electrification despite its abundant renewable energy resources. The region has the highest population without access to electricity, largely due to economic, infrastructural, and geographical barriers. Energy poverty is a critical issue that hinders...

Sub-Saharan Africa, especially its rural areas, faces significant challenges in achieving universal electrification despite its abundant renewable energy resources. The region has the highest population without access to electricity, largely due to economic, infrastructural, and geographical barriers. Energy poverty is a critical issue that hinders...

The escalating demand for water, energy, and food, coupled with the imperative for sustainable development, necessitates innovative solutions to address the complex interdependencies within the water–energy–food nexus. In this context, agriculture and photovoltaics (Agri-PV or Agri–voltaics) systems have emerged as a promising approach to promoting...

For the energy transition in the residential sector, heat pumps are a core technology for decarbonizing thermal energy production for space heating and domestic hot water. Electricity generation from on-site photovoltaic (PV) systems can also contribute to a carbon-neutral building stock. However, both will increase the stress on the electricity gr...

Kyrgyzstan's high-altitude rural housing sector consumes 3–5 times more energy than European buildings due to ageing infrastructure, lack of insulation, and reliance on non-sustainable resources. One potential solution is the implementation of thermal insulation. However, due to limited public awareness of energy efficiency, inadequate government p...

This paper introduces a comprehensive approach for sizing grid-connected hybrid renewable energy systems tailored for electric bus fleet operations. The study involves two main steps. First, a mathematical model that optimizes the configuration of such systems by considering daily electric bus consumption, solar irradiance, wind speed, and biomass...

Buildings in rural Central Asia have unique characteristics as they were built during the Soviet era (during 1950–1960) without any energy efficiency measures. The special and aged building stock pose a crucial challenge on energy security and energy supply. However, accurate scientific data on their energy usage is lacking, highlighting a research...

The high-altitude Central Asian communities (mainly from rural Tajikistan and Kyrgyzstan) face a high degree of energy complexity. The thematic knowledge clearly outlines that these communities hold special energy identity (information about energy requirements, energy consumption, classification of the building, energy resources, energy services,...

More than half of the urban population of Sub-Saharan Africa lives in informal housing conditions. While urban areas are, in general, characterized by a high electrification rate, residents of informal settlements are still affected by energy poverty, the use of traditional energy sources and unreliable electricity supply. The aim of the study is t...

This paper proposes a home energy management system able to achieve optimized load scheduling for the operation of appliances within a given household. The system, based on the genetic algorithm, provides recommendations for the user to improve the way the energy needs of the home are handled. These recommendations not only take into account the dy...

Kyrgyzstan – a high-altitude and cold climatic Central Asian country, suffers from high residential energy consumption, especially in the rural housing sector. Due to the age of the building stock as well as the lack of insulation, the energy consumption of Kyrgyz buildings is 3 to 5 times higher compared to European buildings. The implementation o...

Electromobility emerges as one of the most promising technologies that would facilitate the transition from highly polluting transport systems to zero-emission systems, particularly when powered by renewable energies (RE). Nevertheless, substantial technical, socio-economic, and regulatory barriers must be addressed to achieve the widespread adopti...

The energy situation in informal settlements of Sub-Sahara Africa is often poor. The electricity sector is commonly characterized by unreliable, unaffordable, illegal, or dangerous supply. Energy for cooking and lighting is predominantly based on fossil fuels. One solution to improve the energy supply in informal settlements is the implementation o...

Building construction in rural Kyrgyzstan is heavily dominated by earthen buildings. Old and inappropriate residential building structures contribute significantly to high domestic space heating energy consumption. Therefore, it is necessary to understand the relevant building construction techniques. However, the scant information on Kyrgyz buildi...

Energy is a pivotal element for overall development. Therefore, affordable and clean energy for all (Sustainable Development Goal 7) is one of the important elements. Despite a suitable approach, Kyrgyzstan lags behind to achieve its Sustainable Development Goals by 2030. Improving access to energy can significantly impact the progress of many othe...

Riparian forests are rare and valuable ecosystems in Central Asia, both due to their significance for biodiversity and to their provision of vital ecosystem services to local residents. However, the actual forest use behaviour is under-researched, official figures may not be trustworthy, and the question of over-use is up in the air. This paper set...

Kyrgyzstan – a Central Asian country – faces a high degree of energy insecurity. Especially the Kyrgyz power sector suffers from outdated infrastructure and is not capable of fulfilling the growing and fluctuating inter-seasonal energy demand. On the contrary, the country is endowed with an abundant amount of renewable energies, which can significa...

In diesem Beitrag wurde eine Alternative für ausgeförderte PV-Anlagen im Wohngebäudebereich vorgestellt. Überschüssiger Strom der PV-Anlage wird über Heizstäbe in Form von Wärme in Wärmespeichern zwischengespeichert und dient der Heizungsunterstützung. Es konnte gezeigt werden, dass keine ganzheitliche Lösung auf dem Markt verfügbar ist, welche a)...

In rural Kyrgyzstan, the energy need is usually derived from multiple natural energy resources such as firewood, charcoal, agricultural residues, animal dung, and wood branches, which are considered common and predominant practices. Because of the non-sustainable resources and heavy reliance on the environment, Kyrgyzstan is one of the most vulnera...

ANN models have proven to be robust enough to encapsulate variations in the input-output relationship of weather parameters and photovoltaic (PV) output power, making it one of the most effective and applied statistical machine learning techniques in solar power forecasting. This article presents the development of a Feed-Forward Multi-Layer Percep...

Citation: Bugaje, A.; Ehrenwirth, M.; Trinkl, C.; Zörner, W. Electric Two-Wheeler Vehicle Integration into Rural Off-Grid Photovoltaic System in Kenya. Energies 2021, 14, 7956. Abstract: In both rural and urban areas, two-wheeler vehicles are the most common means of transportation , contributing to local air pollution and greenhouse gas emissions...

The floodplain areas along the Naryn River in Kyrgyzstan are essential as they hold the riparian (local) ecosystems because they provide firewood, pastureland, and areas for recreation and protection against erosion. Due to limited access to adequate, reliable, and sustainable energy services, the rural population usually derived their energy needs...

Due to limited access to adequate, reliable, and sustainable energy services in rural areas, energy is a costly and crucial task in rural Kyrgyzstan. The energy need is usually derived from multiple natural energy resources such as firewood, charcoal, agricultural residues, animal dung, and wood branches, which are considered common and predominant...

In the solar thermal industry, there is a trend towards large-scale solar district heating plants. However, building large plants can also lead to problematic fluctuations in demand for collector manufacturers. To tackle this issue, an innovative concept was introduced which adapts the collector design to production techniques of the insulating gla...

ANN models have proven to be robust enough to encapsulate variations in the input-output relationship of weather parameters and photovoltaic (PV) output power, making it one of the most effective and applied statistical machine learning techniques in solar power forecasting. This article presents the development of a Feed-Forward Multi-Layer Percep...

On the one hand, high-altitude rural Kyrgyz houses have a high heat demand, especially due to the age of buildings and low temperatures in winter evoked by the cold climate. On the other hand, this continental climate results in a high amount of solar irradiation over the year which is ideal for the application of solar systems and in particular so...

Kyrgyzstan is known for being a high-altitude and cold climatic country of Central Asia. Due to mountainous characteristics and permanent glaciers, enormous water resources are abstracted at the county's disposal. Because of the endowed water resources, the majority of the power is generated with hydropower facilities. However, the Kyrgyz power sec...

The heat demand for residential households in cold-climatic environments such as high-altitude rural Kyrgyzstan can be 300 kWh/(m 2 ·a) or above. It has been identified that leakages and a lack of insulation are the main reasons for this high heat demand. Typically, insulation materials, compounded of oil-based plastics and foams (like extruded pol...

The northern part of the globe is dominated by industrialisation and is well-developed. For many years, the southern part of the world (South Asia, Africa etc.) has been a target of research concentrating on access to energy (mainly electricity) in rural regions. However, the Central Asian region has not been a focus of energy research compared to...

Over the last years, stand-alone and / or hybrid photovoltaic systems have spread in rural areas especially in Sub-Saharan Africa. Compared to conventional systems (typically diesel generators), these systems can provide a reliable electricity supply at reasonable costs with low degree of greenhouse gas emissions. Therefore, this paper focuses on m...

The electric output and efficiency of the Photovoltaic (PV) devices are strongly dependent on metrological variables such as solar irradiation, wind speed and ambient temperature. It is therefore important to optimise the size and electrical loads of an off-grid PV system to meet the required load demands at least cost. However, sizing results depe...

The aim of this study was to develop the profile and competencies of a harmonised curriculum for a multi-country regional sector-specific higher education programme. The study, which was based on a case study of Renewable Energy involving six countries in Southern Africa, was based on established methodologies proposed by previous studies on harmon...

The floodplain ecosystems along the Naryn River in Kyrgyzstan still show largely natural dynamics and represent a regional hotspot of biodiversity. For the local population, they provide important ecosystem services, such as the provision of firewood and pasture land, areas for recreation and protection against erosion. However, the intensive use o...

A large part of the Kyrgyz territory is covered by mountain ranges which result in extremely cold winter periods. The cold climatic conditions of Kyrgyzstan define heating as an essential need for Kyrgyz people. The majority of the residential buildings are constructed with poor thermal insulation or none at all, which yields high energy consumptio...

Kyrgyzstan is a high-altitude mountainous country situated in a cold climatic zone. The age of the residential buildings, poor housing conditions and the absence of proper thermal insulation result in high heat demand and low thermal comfort in Kyrgyz houses. To maintain thermal comfort, the rural residents use traditional heating stoves to burn so...

Currently, the expansion of electricity generation from renewable energy sources is mainly taking place on the medium and low voltage level of the electricity grid in Germany. Therefore, the potential of combining biogas and PV power plants in hybrid systems in the German distribution grid is analyzed. The focus of the present research is on balanc...

Fossil fuels are currently used to generate the major part of process steam for industrial facilities. An established approach for the sustainable substitution of fossil resources is the supply from solid biomass-fuelled combined heat and power (CHP) plants. However, current designs of biomass CHP plants usually raise only a share of the total stea...

Within the present study a novel concept for the demand-oriented power generation of a solid-biomass fueled combined heat and power (CHP) plant is investigated. The integration of a novel steam storage system into the plants process enables a decoupling of the steam (boiler) and the power generation (steam turbine). By buffering the steam, the powe...

Flexible power provision from biogas can significantly contribute to energy systems with high shares of renewables. However, the characteristics and demands for this flexibility are not clearly defined or measured. In this paper eight indicators are defined to shape “flexibility” and perform a downstream investigation of eight research projects foc...

The increasing number of fluctuating renewable power producers in the electricity grid leads to several challenges in the grid's infrastructure and its operation. Biomass combustion plants, however, can be modified to increase the flexibility of power production by integrating steam storage devices. In this paper, the available storage systems are...

Process steam, which shows a wide scope of utilization in various industrial processes, is currently predominantly generated by fossil fuels. An instant measure in order to reduce greenhouse gas emissions is, therefore, to substitute fossil fuel-based steam production by biomass combustion plants in Combined Heat and Power (CHP) operation. Because...

Während der Ausbau der Erneuerbaren Energien zügig voranschreitet ergeben sich gleichzeitig bei vielen Aspekten der Energiewende neue Fragestellungen und Problemlagen. Die Fachtagung „Optimierung in der Energiewirtschaft“ gibt hier einen Überblick über Methoden und Modelle, die eingesetzt werden können, um die Transformation des Energiesystems erfo...

The current state of the art in mixing of biogas digesters is described and the areas where future research needs to be concentrated are outlined. Since mixing is the biggest contributor to energy consumption in digesters, it is important to optimize it in order to improve the overall cost-effectiveness of biodigestion. This optimization problem is...

The increasing share of fluctuating energy generation causes new challenges in the power grids. The demand for flexible power plants is increasing. Solid biomass fueled combined heat and power (CHP) plants are able to get modified into dispatchable power plants. In this paper, boundaries for this operation mode are summarized and several measures t...

With the expansion of renewable but fluctuating power generation from wind and solar energy, the demand placed on the security and reliability of supply is increasing. To ensure grid stability in the future, controllable power production via biogas plants has great technical and economic potential. In order to demonstrate the operation of controlla...

The ‘Network of Excellence in Renewable Energy Technologies for Development’ also known as "Network of Energy Excellence for Development" (NEED), comprises a consortium of five partner institutions from Botswana, Germany, Namibia and Zambia undertaking collaborative research aimed at kick-starting and institutionalizing the widespread exploitation...

A mathematical model of a flat-plate solar collector was developed on the basis of the physical principles of optics and heat transfer in order to determine collector’s component temperatures as well as collector efficiency. In contrast to many available models, the targeted use of this dynamic model is the detailed, theoretical investigation of th...

A dynamic flat-plate collector model for parametric sensitivity studies on polymer-based collector designs was developed. Validation using experimental results of conventional flat-plate collectors showed satisfying results especially regarding the calculation of individual part temperatures of a collector. The model was used to predict system effi...