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Seasonal thermal energy storage (STES) of solar heat is an option of interest for clean heat transition, as residential heating is often fossil fuel-based. This study 1) proposes an integrated optimization criterion to examine how local context influences the optimal configuration planning, techno-economic-environmental performance, and feasibility of STES application; 2) identifies the position of STES in comparison to other sustainable heating options considering the local context; and 3) provides a comprehensive and transparent showcase highlighting the importance of the local context in determining the feasibility of STES in the clean heating transition. The TRNSYS modeling tool is adopted to analyze the performance, and Pareto optimization is applied to treat the multi-objective optimization. The solar fractions and storage efficiencies of the four case studies range between 58-67% and 57–69%, respectively. STES has significant potential to reduce CO2 emissions (52–72%) compared to conventional heating systems. However, the heating cost of the STES system (5.4–8.7 €-ct/kWh) is more than twice that of the conventional heating system. The CO2 avoidance cost of the four case studies ranges between 114 and 368 €/t. Properly reducing the borehole number in cold climate zones and increasing the solar collector area in warm climate zones help improve the system performance.

Industrial heat production is responsible for around 20% of total greenhouse gas emissions in Europe. To achieve the climate change goals defined in the Paris Climate Agreement, the EU commission has shifted its focus on sustainable means to generate heating. Moreover, global dependencies are leading to a re-organization of natural gas supplies. Therefore, there is a need for less vulnerable and less price-volatile solutions for heating. This paper focuses on two decarbonization technologies for industrial process heat supply: a) electricity-driven steam-generating high-temperature heat pumps (HTHP), a technology that is more efficient than fossil fuel boilers in generating steam, and b) solar parabolic trough collector (PTC), which can produce heat economically and at a minimal carbon footprint compared to other technologies. The main aim of this paper is to evaluate the levelized cost of heat (LCOH) of these technologies to fulfill a comparative techno-economic analysis. A maximum PTC collector's solar fraction limit (SFlimit) is defined to indicate when the LCOH for these two technologies is equal. This allows for distinguishing between the economic stronghold of each technology. The evaluation is carried out through the annual energy simulations using TRNSYS and Excel spreadsheets for HTHPs, while TRNSED and OCTAVE are used for the solar thermal part. Boundary conditions for European geographical constraints have been applied to establish use cases for the analysis. The result shows that the design of a PTC system with optimal SF can reach cost parity with HTHP for most of the analyzed locations. The developed methodology serves as a valuable guide to quickly determine a preferred lower carbon heat solution, thus easing the decision-making for industries.

Industrial heat production is responsible for around 20% of total greenhouse gas emissions in Europe. To achieve the climate change goals defined in the Paris Climate Agreement, the EU commission has shifted its focus on sustainable means to generate heating. Moreover, global dependencies are leading to a re-organization of natural gas supplies. Therefore, there is a need for less vulnerable and less price-volatile solutions for heating. This paper focuses on two decarbonization technologies for industrial process heat supply: a) electricity-driven steam-generating high-temperature heat pumps (HTHP), a technology that is more efficient than fossil fuel boilers in generating steam, and b) solar parabolic trough collector (PTC), which can produce heat economically and at a minimal carbon footprint compared to other technologies. The main aim of this paper is to evaluate the levelized cost of heat (LCOH) of these technologies to fulfill a comparative techno-economic analysis. A maximum PTC collector's solar fraction limit (SFlimit) is defined to indicate when the LCOH for these two technologies is equal. This allows for distinguishing between the economic stronghold of each technology. The evaluation is carried out through the annual energy simulations using TRNSYS and Excel spreadsheets for HTHPs, while TRNSED and OCTAVE are used for the solar thermal part. Boundary conditions for European geographical constraints have been applied to establish use cases for the analysis. The result shows that the design of a PTC system with optimal SF can reach cost parity with HTHP for most of the analyzed locations. The developed methodology serves as a valuable guide to quickly determine a preferred lower carbon heat solution, thus easing the decision-making for industries.

Industrial heat production is responsible for around 20% of total greenhouse gas emissions in Europe. To achieve the climate change goals defined in the Paris Climate Agreement, the EU commission has shifted its focus on sustainable means to generate heating. Moreover, global dependencies are leading to a re-organization of natural gas supplies. Therefore, there is a need for less vulnerable and less price-volatile solutions for heating. This paper focuses on two decarbonization technologies for industrial process heat supply: a) electricity-driven steam-generating high-temperature heat pumps (HTHP), a technology that is more efficient than fossil fuel boilers in generating steam, and b) solar parabolic trough collector (PTC), which can produce heat economically and at a minimal carbon footprint compared to other technologies. The main aim of this paper is to evaluate the levelized cost of heat (LCOH) of these technologies to fulfill a comparative techno-economic analysis. A maximum PTC collector's solar fraction limit (SFlimit) is defined to indicate when the LCOH for these two technologies is equal. This allows for distinguishing between the economic stronghold of each technology. The evaluation is carried out through the annual energy simulations using TRNSYS and Excel spreadsheets for HTHPs, while TRNSED and OCTAVE are used for the solar thermal part. Boundary conditions for European geographical constraints have been applied to establish use cases for the analysis. The result shows that the design of a PTC system with optimal SF can reach cost parity with HTHP for most of the analyzed locations. The developed methodology serves as a valuable guide to quickly determine a preferred lower carbon heat solution, thus easing the decision-making for industries.

Industrial heat production is responsible for around 20% of total greenhouse gas emissions in Europe. To achieve the climate change goals defined in the Paris Climate Agreement, the EU commission has shifted its focus on sustainable means to generate heating. Moreover, global dependencies are leading to a re-organization of natural gas supplies. Therefore, there is a need for less vulnerable and less price-volatile solutions for heating. This paper focuses on two decarbonization technologies for industrial process heat supply: a) electricity-driven steam-generating high-temperature heat pumps (HTHP), a technology that is more efficient than fossil fuel boilers in generating steam, and b) solar parabolic trough collector (PTC), which can produce heat economically and at a minimal carbon footprint compared to other technologies. The main aim of this paper is to evaluate the levelized cost of heat (LCOH) of these technologies to fulfill a comparative techno-economic analysis. A maximum PTC collector's solar fraction limit (SFlimit) is defined to indicate when the LCOH for these two technologies is equal. This allows for distinguishing between the economic stronghold of each technology. The evaluation is carried out through the annual energy simulations using TRNSYS and Excel spreadsheets for HTHPs, while TRNSED and OCTAVE are used for the solar thermal part. Boundary conditions for European geographical constraints have been applied to establish use cases for the analysis. The result shows that the design of a PTC system with optimal SF can reach cost parity with HTHP for most of the analyzed locations. The developed methodology serves as a valuable guide to quickly determine a preferred lower carbon heat solution, thus easing the decision-making for industries.

Industrial heat production is responsible for around 20% of total greenhouse gas emissions in Europe. To achieve the climate change goals defined in the Paris Climate Agreement, the EU commission has shifted its focus on sustainable means to generate heating. Moreover, global dependencies are leading to a re-organization of natural gas supplies. Therefore, there is a need for less vulnerable and less price-volatile solutions for heating. This paper focuses on two decarbonization technologies for industrial process heat supply: a) electricity-driven steam-generating high-temperature heat pumps (HTHP), a technology that is more efficient than fossil fuel boilers in generating steam, and b) solar parabolic trough collector (PTC), which can produce heat economically and at a minimal carbon footprint compared to other technologies. The main aim of this paper is to evaluate the levelized cost of heat (LCOH) of these technologies to fulfill a comparative techno-economic analysis. A maximum PTC collector's solar fraction limit (SFlimit) is defined to indicate when the LCOH for these two technologies is equal. This allows for distinguishing between the economic stronghold of each technology. The evaluation is carried out through the annual energy simulations using TRNSYS and Excel spreadsheets for HTHPs, while TRNSED and OCTAVE are used for the solar thermal part. Boundary conditions for European geographical constraints have been applied to establish use cases for the analysis. The result shows that the design of a PTC system with optimal SF can reach cost parity with HTHP for most of the analyzed locations. The developed methodology serves as a valuable guide to quickly determine a preferred lower carbon heat solution, thus easing the decision-making for industries.

In response to the European Commission's renewable energy targets for 2030, this study presents a comprehensive, data-driven evaluation of the potential for electricity self-consumption in the Spanish residential sector based on rooftop PV systems. Utilizing real-time hourly electricity demand data and various surplus compensation policies, the research highlights the significance of data granularity, indicating that annual data-based PV estimations can lead to rooftop PV self-consumption capacity overestimations when compared to hourly data assessments. Furthermore, geographical variations reveal distinct rooftop PV self-consumption capacities between urban and rural areas, driven mainly by the prevalent building typologies. This discrepancy suggests that while rural regions, with their predominance of single-family dwellings, offer higher PV generation potential due to more available rooftop space, urban areas, dominated by multi-story buildings, face significant constraints in rooftop surface availability. Economically, the current surplus compensation policy in Spain reduces the profitability of PV installations, underscoring the necessity for enhanced policies to fully utilize all the available rooftop areas in the residential sector. The study's findings, particularly the revelation that residential rooftops in Spain may not be enough to meet the current electricity demand, emphasize the need for adaptive, region-specific policies and the potential role of energy communities. Policymakers and industry stakeholders are urged to prioritize rooftop utilization, ensuring the deployment of PV systems is both promoted and economically viable, steering Spain closer to its renewable energy and sustainability aspirations.

To increase knowledge about reducing the carbon footprint of air conditioning in buildings, this study simulated and compared solar collector and thermal storage options and configurations for a solar absorption chiller to maximize the use of solar resources. From these findings a design was found that could supply cooling to a commercial building in Brisbane at 99.7 percent solar fraction.

Renewable sources will play a key role in meeting the EU targets for 2030. The combined use of an aerothermal source through a heat pump and a solar source with a photovoltaic (PV) system is one feasible and promising technology for the heating and cooling of residential spaces. In this study, a detailed model of a single-family house with an air-source heat pump and a PV system is developed with the TRNSYS simulation software. Yearly simulations are run for two types of buildings and nine European climates, for both heating and cooling (where needed), in order to have an overview of the system behaviour, which is deeply influenced by the climate. The storage system (electrical and thermal) is also investigated, by means of multiple simulation scenarios, with and without the battery and with different water storage sizes. The numerical results provide an overview of the performance of the considered heating and cooling system, as well as the balance of the electrical energy exchange between the grid, the building, and the PV array., E Psimopoulos hittas inte i MP. 190620/kg

High-rise buildings have a significant impact on the surrounding environment.Building-integrated solar water heating (SWH) systems are effective ways to use renewable energy inbuildings. Impediments, such as security concerns, aesthetics and functionality, make it difficult toapply SWH systems in high-rise buildings. At present, only China uses SWH systems on a large scalein such buildings. What are China’s experiences and lessons learned in applying SWH systems inhigh-rises? Are these experiences scalable to other countries? This study used a combination of fieldinvestigation, literature review and case study to summarize 36 systems that had been in operationfor 1–14 years. System types, collector types, installation methods, types of auxiliary heat sources,economic performance and various basic principles were summarized. The economic performance ofSWH systems in high-rise buildings was analyzed and verified by a case study in Shanghai. Theresults show that the installation of SWH systems in high-rise buildings is feasible and reliable.Individual household systems (61%) were more popular than centralized systems (25%) and hybridsystems account (14%). The average area of solar collectors per household was 2.17 m2/household,the average design solar fraction was 52%. Flat plate solar collectors (53%) was the most commonlyused collector, while electric heating elements (89%) were the most common auxiliary heat sources forSWH systems, followed by gas water heaters and air source heat pumps. The cost of SWH systemsper m2 of a building area was between 22 CNY/m2to 75 CNY/m2. China’s unique practical experiencegives a reference for other countries in their efforts to make high-rise buildings more sustainable.

In this study a detailed model of a single-family house with an exhaust air heat pump and photovoltaic system is developed in the simulation software TRNSYS. The model is used to evaluate three control algorithms using thermal and electrical storage in terms of final energy, solar fraction, self-consumption and seasonal performance factor. The algorithms are tested and compared with respect to energetic improvement for 1) use of the heat pump plus storage tank for domestic hot water and space heating, 2) use of the electrical storage in batteries and 3) use of both electrical and thermal storage. Results show the highest increase of self-consumption to 50.5%, solar fraction to 40.6% and final energy decrease to 6923 kWh by implementing the third algorithm in a system with 9.36 kW PV capacity and battery storage of 10.8 kWh. The use of electrical energy storage has higher positive impact compared to the thermal storage with the settings and component sizes used. The combined use of thermal storage and batteries leads to final energy savings that are nearly the same as the combined savings of thermal storage and batteries separately, showing that they are mostly independent of one another for the settings of this study.

In this study a detailed model of a single-family house with an exhaust air heat pump and photovoltaic system is developed in the simulation software TRNSYS. The model is used to evaluate three control algorithms using thermal and electrical storage in terms of final energy, solar fraction, self-consumption and seasonal performance factor. The algorithms are tested and compared with respect to energetic improvement for 1) use of the heat pump plus storage tank for domestic hot water and space heating, 2) use of the electrical storage in batteries and 3) use of both electrical and thermal storage. Results show the highest increase of self-consumption to 50.5%, solar fraction to 40.6% and final energy decrease to 6923 kWh by implementing the third algorithm in a system with 9.36 kW PV capacity and battery storage of 10.8 kWh. The use of electrical energy storage has higher positive impact compared to the thermal storage with the settings and component sizes used. The combined use of thermal storage and batteries leads to final energy savings that are nearly the same as the combined savings of thermal storage and batteries separately, showing that they are mostly independent of one another for the settings of this study.

In this study a detailed model of a single-family house with an exhaust air heat pump and photovoltaic system is developed in the simulation software TRNSYS. The model is used to evaluate three control algorithms using thermal and electrical storage in terms of final energy, solar fraction, self-consumption and seasonal performance factor. The algorithms are tested and compared with respect to energetic improvement for 1) use of the heat pump plus storage tank for domestic hot water and space heating, 2) use of the electrical storage in batteries and 3) use of both electrical and thermal storage. Results show the highest increase of self-consumption to 50.5%, solar fraction to 40.6% and final energy decrease to 6923 kWh by implementing the third algorithm in a system with 9.36 kW PV capacity and battery storage of 10.8 kWh. The use of electrical energy storage has higher positive impact compared to the thermal storage with the settings and component sizes used. The combined use of thermal storage and batteries leads to final energy savings that are nearly the same as the combined savings of thermal storage and batteries separately, showing that they are mostly independent of one another for the settings of this study.

The paper presents the results of a simulation study, in which the connection of heat pumps and buffer storage tanks has been investigated. The simulations are carried out for a new type of a solar thermal combi system with a 32 m2 collector field leading to a solar fraction of more than 50%. In the first stage, the most influencing installation and operation parameters have been identified and optimized for typical boundary conditions of weather/climate, hot water demand, building and space heating system. Within further simulations these boundary conditions are varied to find generalized design rules for the connection of heat pumps and storage tanks. These results are presented and discussed.

In this study a detailed model of a single-family house with an exhaust air heat pump and photovoltaic system is developed in the simulation software TRNSYS. The model is used to evaluate three control algorithms using thermal and electrical storage in terms of final energy, solar fraction, self-consumption and seasonal performance factor. The algorithms are tested and compared with respect to energetic improvement for 1) use of the heat pump plus storage tank for domestic hot water and space heating, 2) use of the electrical storage in batteries and 3) use of both electrical and thermal storage. Results show the highest increase of self-consumption to 50.5%, solar fraction to 40.6% and final energy decrease to 6923 kWh by implementing the third algorithm in a system with 9.36 kW PV capacity and battery storage of 10.8 kWh. The use of electrical energy storage has higher positive impact compared to the thermal storage with the settings and component sizes used. The combined use of thermal storage and batteries leads to final energy savings that are nearly the same as the combined savings of thermal storage and batteries separately, showing that they are mostly independent of one another for the settings of this study.

In this study a detailed model of a single-family house with an exhaust air heat pump and photovoltaic system is developed in the simulation software TRNSYS. The model is used to evaluate three control algorithms using thermal and electrical storage in terms of final energy, solar fraction, self-consumption and seasonal performance factor. The algorithms are tested and compared with respect to energetic improvement for 1) use of the heat pump plus storage tank for domestic hot water and space heating, 2) use of the electrical storage in batteries and 3) use of both electrical and thermal storage. Results show the highest increase of self-consumption to 50.5%, solar fraction to 40.6% and final energy decrease to 6923 kWh by implementing the third algorithm in a system with 9.36 kW PV capacity and battery storage of 10.8 kWh. The use of electrical energy storage has higher positive impact compared to the thermal storage with the settings and component sizes used. The combined use of thermal storage and batteries leads to final energy savings that are nearly the same as the combined savings of thermal storage and batteries separately, showing that they are mostly independent of one another for the settings of this study.

The paper presents the results of a simulation study, in which the connection of heat pumps and buffer storage tanks has been investigated. The simulations are carried out for a new type of a solar thermal combi system with a 32 m2 collector field leading to a solar fraction of more than 50%. In the first stage, the most influencing installation and operation parameters have been identified and optimized for typical boundary conditions of weather/climate, hot water demand, building and space heating system. Within further simulations these boundary conditions are varied to find generalized design rules for the connection of heat pumps and storage tanks. These results are presented and discussed.

Predmet rada ove doktorske disertacije je dinamička simulacija i optimizacija solarnih instalacija za grejanje sanitarne tople vode (STV) koje opslužuju kuće neto-nulte potrošnje energije. Rad se bavi optimizacijom projektovanja, realizacijom u praksi i radom solarnih prijemnika u prostoru i vremenu kao elemenata solarnih instalacija koje se izučavaju. Naučni cilj disertacije je utvrđivanje uticaja pojedinih projektnih elemenata instalacije, načina rada sa instalacijom, energetskih potreba kuće sa neto-nultom potrošnjom, utvrđivanje uticaja meteoroloških parametara na optimalni položaj solarnog prijemnika u vremenu i prostoru, kao i uspostavljanje odgovarajuće međusobne zavisnosti svih tih parametara. Glavne prednosti instalacije ispitivane u ovoj doktorskoj disertaciji, u odnosu na prethodna istraživanja su da su optimizovanjem položaja prijemnika solarne energije kod kuća sa neto-nultom potrošnjom energije dobijene najveće vrednosti solarnog udela. Unapređeni solarni energetski sistemi omogućili su da se ostvare maksimalne vrednosti energije i eksergije, sa maksimalnom energetskom i eksergetskom efikasnošću, kao i minimalnim utroškom fosilne energije. Pored navedenih prednosti korišćenje ovakvih sistema omogućava smanjenje korišćenja energetskih resursa, maksimiranje energetske sigurnosti i minimiziranje uticaja na okolnu sredinu. S ciljem utvrđivanja izvodljivosti predloženog koncepta korišćene su savremene metode energomonitoringa i energodijagnostike, sprovedena su ispitivanja solarne instalacije kod kuća neto-nulte potrošnje energije razvijanjem matematičkog modela, metodologije i algoritma za dinamičku simulaciju i optimizaciju rada solarne instalacije. Analizom rezultata istraživanja zaključeno je da postoji opravdanost postavljanja solarnog prijemnika u tačno optimalan položaj u prostoru i vremenu., The subject of this dissertation is dynamic simulation and optimization of solar thermal systems for heating domestic hot water (DHW) in the houses with net-zero energy consumption. The thesis deals with the optimization of design, implementation in practice and operation of the solar collectors in space and time, as elements of solar installations that are explored. Scientific objective of the dissertation is to determine the impact of certain project elements of installation, operating modes with the installation, the energy needs of the house with a net-zero energy, as well as meteorological parameters on the optimal position of the solar collectors in space and time, as well as the establishment of an appropriate interdependency of all these parameters. The main advantages of the installation investigated in this doctoral dissertation, compared to the previous research, are that by optimizing the position of solar collectors in houses with net-zero solar energy we obtain the maximum value of the solar fraction. Solar energy systems have been improved, whereby we obtain the maximum value of energy and exergy, with maximum energy and exergy efficiency, minimum consumption of fossil energy, reduction of the use of energy resources, maximizing energy security, as well as minimum impact on the environment. In order to determine the feasibility of the proposed concept modern methods of energy monitoring and energy diagnostics, investigations of the solar installation in a house with in net-zero-energy consumption have been implemented, by developing a mathematical model, methodologies, and an algorithm for dynamic simulation and optimization of the solar installation operation. Based on the analysed research results it has been concluded that setting up a solar collector at an exactly optimal position in space and time is justified.

Application of seasonal thermal energy storage with heat pumps for heating and cooling buildings has received much consideration in recent decades, as it can help to cover gaps between energy availability and demand, e.g. from summer to winter. This has the potential to reduce the large proportion of energy consumed by buildings, especially in colder climate countries. The problem with seasonal storage, however, is heat loss. This can be reduced by low-temperature storage but a heat pump is then recommended to adjust temperatures as needed by buildings in use. The aim of this paper was to compare different seasonal thermal energy storage methods using a heat pump in terms of coefficient of performance (COP) of heat pump and solar fraction, and further, to investigate the relationship between those factors and the size of the system, i.e. collector area and storage volume based on past building projects including residences, offices and schools., QC 20150623

Application of seasonal thermal energy storage with heat pumps for heating and cooling buildings has received much consideration in recent decades, as it can help to cover gaps between energy availability and demand, e.g. from summer to winter. This has the potential to reduce the large proportion of energy consumed by buildings, especially in colder climate countries. The problem with seasonal storage, however, is heat loss. This can be reduced by low-temperature storage but a heat pump is then recommended to adjust temperatures as needed by buildings in use. The aim of this paper was to compare different seasonal thermal energy storage methods using a heat pump in terms of coefficient of performance (COP) of heat pump and solar fraction, and further, to investigate the relationship between those factors and the size of the system, i.e. collector area and storage volume based on past building projects including residences, offices and schools., QC 20150623

The demand for cooling and air-conditioning of building is increasingly ever growing. This increase is mostly due to population and economic growth in developing countries, and also desire for a higher quality of thermal comfort. Increase in the use of conventional cooling systems results in larger carbon footprint and more greenhouse gases considering their higher electricity consumption, and it occasionally creates peaks in electricity demand from power supply grid. Solar energy as a renewable energy source is an alternative to drive the cooling machines since the cooling load is generally high when solar radiation is high. This thesis examines the performance of PV/T solar collector manufactured by Solarus company in a solar cooling system for an office building in Dubai, New Delhi, Los Angeles and Cape Town. The study is carried out by analyzing climate data and the requirements for thermal comfort in office buildings. Cooling systems strongly depend on weather conditions and local climate. Cooling load of buildings depend on many parameters such as ambient temperature, indoor comfort temperature, solar gain to the building and internal gains including; number of occupant and electrical devices. The simulations were carried out by selecting a suitable thermally driven chiller and modeling it with PV/T solar collector in Polysun software. Fractional primary energy saving and solar fraction were introduced as key figures of the project to evaluate the performance of cooling system. Several parametric studies and simulations were determined according to PV/T aperture area and hot water storage tank volume. The fractional primary energy saving analysis revealed that thermally driven chillers, particularly adsorption chillers are not suitable to be utilizing in small size of solar cooling systems in hot and tropic climates such as Dubai and New Delhi. Adsorption chillers require more thermal energy to meet the cooling load in hot and dry climates. The adsorption chil

The demand for cooling and air-conditioning of building is increasingly ever growing. This increase is mostly due to population and economic growth in developing countries, and also desire for a higher quality of thermal comfort. Increase in the use of conventional cooling systems results in larger carbon footprint and more greenhouse gases considering their higher electricity consumption, and it occasionally creates peaks in electricity demand from power supply grid. Solar energy as a renewable energy source is an alternative to drive the cooling machines since the cooling load is generally high when solar radiation is high. This thesis examines the performance of PV/T solar collector manufactured by Solarus company in a solar cooling system for an office building in Dubai, New Delhi, Los Angeles and Cape Town. The study is carried out by analyzing climate data and the requirements for thermal comfort in office buildings. Cooling systems strongly depend on weather conditions and local climate. Cooling load of buildings depend on many parameters such as ambient temperature, indoor comfort temperature, solar gain to the building and internal gains including; number of occupant and electrical devices. The simulations were carried out by selecting a suitable thermally driven chiller and modeling it with PV/T solar collector in Polysun software. Fractional primary energy saving and solar fraction were introduced as key figures of the project to evaluate the performance of cooling system. Several parametric studies and simulations were determined according to PV/T aperture area and hot water storage tank volume. The fractional primary energy saving analysis revealed that thermally driven chillers, particularly adsorption chillers are not suitable to be utilizing in small size of solar cooling systems in hot and tropic climates such as Dubai and New Delhi. Adsorption chillers require more thermal energy to meet the cooling load in hot and dry climates. The adsorption chil

Application of seasonal thermal energy storage with heat pumps for heating and cooling buildings has received much consideration in recent decades, as it can help to cover gaps between energy availability and demand, e.g. from summer to winter. This has the potential to reduce the large proportion of energy consumed by buildings, especially in colder climate countries. The problem with seasonal storage, however, is heat loss. This can be reduced by low-temperature storage but a heat pump is then recommended to adjust temperatures as needed by buildings in use. The aim of this paper was to compare different seasonal thermal energy storage methods using a heat pump in terms of coefficient of performance (COP) of heat pump and solar fraction, and further, to investigate the relationship between those factors and the size of the system, i.e. collector area and storage volume based on past building projects including residences, offices and schools., QC 20150623

Application of seasonal thermal energy storage with heat pumps for heating and cooling buildings has received much consideration in recent decades, as it can help to cover gaps between energy availability and demand, e.g. from summer to winter. This has the potential to reduce the large proportion of energy consumed by buildings, especially in colder climate countries. The problem with seasonal storage, however, is heat loss. This can be reduced by low-temperature storage but a heat pump is then recommended to adjust temperatures as needed by buildings in use. The aim of this paper was to compare different seasonal thermal energy storage methods using a heat pump in terms of coefficient of performance (COP) of heat pump and solar fraction, and further, to investigate the relationship between those factors and the size of the system, i.e. collector area and storage volume based on past building projects including residences, offices and schools., QC 20150623

Application of seasonal thermal energy storage with heat pumps for heating and cooling buildings has received much consideration in recent decades, as it can help to cover gaps between energy availability and demand, e.g. from summer to winter. This has the potential to reduce the large proportion of energy consumed by buildings, especially in colder climate countries. The problem with seasonal storage, however, is heat loss. This can be reduced by low-temperature storage but a heat pump is then recommended to adjust temperatures as needed by buildings in use. The aim of this paper was to compare different seasonal thermal energy storage methods using a heat pump in terms of coefficient of performance (COP) of heat pump and solar fraction, and further, to investigate the relationship between those factors and the size of the system, i.e. collector area and storage volume based on past building projects including residences, offices and schools., QC 20150623

A theoretical analysis of differently designed solar combi systems is performed with weather data from the Danish Design Reference Year (55ºN). Three solar combi system designs found on the market are investigated. The investigation focuses on the influence of stratification on the thermal performance under different operation conditions with different domestic hot water and space heating demands. The solar combi systems are initially equipped with heat exchanger spirals and direct inlets to the tank. A step-by-step investigation is performed demonstrating the influence on the thermal performance of using inlet stratification pipes at the different inlets. Also, it is investigated how the design of the space heating system, the control system of the solar collectors, and the system size influence the thermal performance of solar combi systems. The work is carried out within the Solar Heating and Cooling Programme of the International Energy Agency (IEA SHC), Task 32.

A theoretical analysis of differently designed solar combi systems is performed with weather data from the Danish Design Reference Year (55ºN). Three solar combi system designs found on the market are investigated. The investigation focuses on the influence of stratification on the thermal performance under different operation conditions with different domestic hot water and space heating demands. The solar combi systems are initially equipped with heat exchanger spirals and direct inlets to the tank. A step-by-step investigation is performed demonstrating the influence on the thermal performance of using inlet stratification pipes at the different inlets. Also, it is investigated how the design of the space heating system, the control system of the solar collectors, and the system size influence the thermal performance of solar combi systems. The work is carried out within the Solar Heating and Cooling Programme of the International Energy Agency (IEA SHC), Task 32.