Renewable Energy Sources For Heating Research Articles

«THERMAL COUP» OF VICE-CHANCELLOR R. HABECK: CONSEQUENCES FOR GERMANY’s ECONOMICS AND POLITICS

In the face of new challenges for the energy transition, since spring 2022, the German Cabinet of Ministers has been paying special attention to the energy saving of buildings, which are one of the main sources of greenhouse gas emissions into the atmosphere. The Federal Ministry for Economic Affairs and Climate Protection has consistently increased the mandatory use of renewable energy sources for heating and electricity consumption. Since the beginning of 2023, at the initiative of its head, at the same time acting vice-chancellor, R. Habeck, a mechanism for the preferential use of heat pumps as a strategic basis for the so-called thermal transition has been discussed at the government level. The peculiarity was the absence of a traditional organized public discussion in such cases with the involvement of specialized interest groups. Moreover, facts of internal lobbying at the level of one of the state secretaries of the ministry were revealed. In April, the government coalition proposed a draft to make a number of qualitative changes to the Law on the Energy of Buildings. It provoked sharp criticism and rejection from the Free Democratic Party, the expert and business community, as well as representatives of federal subjects. Against this background, German and foreign manufacturers of heat pumps have stepped up efforts to conquer new market niches. The article examines the essence of the amendments proposed by the coalition, the prospects for their adoption, the content of criticism of the bill by specialized associations and unions, the possible consequences of the future law for economic and economic political processes in Germany.

A study on Incorporating Zero Energy Building Features in a Residential Building

Any building has significant impact on the energy use and the environment which can potentially affect the development of a country. It is highly important to minimize energy usage to preserve the environment. Energy usage also causes climatic changes, environmental degradation and increases the air pollution. The amount of energy utilization should be considerably reduced in all types of buildings to make environmentally sustainable towns and cities. The buildings that utilize minimum energy and discharges minimum waste in to the environment can be called zero energy buildings. Zero energy buildings offer numerous advantages to the society as a whole. The aim of this study is to focus on the zero energy components that can be incorporated to create Net Zero energy by using various energy resources. The study discusses the various energy optimization features in a residential building of around 2000 sq. ft area. The building is energy sufficient building and it uses renewable energy sources for heating and power generation to operate the electrical and electronic appliances.

Experimental investigation and modelling of a laboratory-scale latent heat storage with cylindrical PCM capsules

Heat storage efficiency is required to maximize the potential of combined heat and power generation or renewable energy sources for heating. Using a phase change material (PCM) could be an attractive choice in several instances. Commercially available paraffin-based PCM was investigated using T-history method with sufficient agreement with the data from the manufacturer. The introduced LHTES with cylindrical capsules is simple and scalable in capacity, charging/discharging time, and temperature level. The overall stored energy density is 9% higher than the previously proposed design of similar design complexity. The discharging process of the designed latent heat thermal energy storage (LHTES) was evaluated for two different flow rates. The PCM inside the capsules and heat transfer fluid (HTF) temperature, as well as the HTF flow rate, were measured. The lumped parameter numerical model was developed and validated successfully. The advantage of the proposed model is its computational simplicity, and thus the possibility to use it in simulations of a whole heat distribution network. The so-called state of charge (SoC), which plays a crucial role in successful heat storage management, is a part of the evaluation of both experimental and computational data.

Building's heat potential on resources in respect to CO2 emissions and primary energy reduction (Case study)

An increased utilization of renewable energy sources for heating and electricity generation is one of the main tasks of the Slovak Republic. The main hypothesis is that heat pumps are very energy-efficient, and therefore environmentally benign, while providing heating and cooling in many applications. Within good conditions, the energy from low-positional heat, in other way unusable, is used to supply the energy for heat pumps. The paper confirms the applicability of such systems for long term (about 25 years). A building in Košice was used as the model of the transformation of a common office object into the character of a green and energy active one with the target programme being a sustainable building with zero balance of the energy from the network. From the comparison of the past and present operation data of the building, it is possible to show the big advantage of the usage of the heat pump water-water to the energy supply system. At favourable technical conditions in a heat supply system, it becomes the most advantageous solution in achieving today’s targets - minimum emission production combined with investment, low operating costs and achieving necessary human thermal comfort. The convenience of the system increases as it can switch between the cooling and heating process according to conditions. For the whole observed period, the energy consumption is reduced by 70%, the primary energy decreased by 69% compared to 1996 and CO2 emissions were reduced by 98%. The simulations of the object were performed and verified based on the measured data.

Increasing efficiency with biomimetic approach in thermoregulative building envelope strategies supporting internal thermal comfort

There has been a plea for sustainable use of resources since the twentieth century. Buildings are known to consume forty percent of the world’s resources. Resources such as gas, oil, coal and electrical energy used in heating, cooling and ventilation of buildings are limited, as well as causing air pollution and climate change. For this reason, the energy resources used in the buildings should be used effectively, considering environmental concerns. The aim of this study is to describe the shift in efficient use of energy in buildings using a biomimetic approach in thermoregulative building envelope strategies that support internal thermal comfort. In this study, passive systems integrated into buildings which use solar energy, one of the renewable energy sources for heating, cooling and ventilation purposes have been examined. The methods followed by nature in using solar energy are discussed with the biomimetic approach and suggestions have been made to support the increase of energy efficiency by applying the obtained teachings to passive building envelopes. Keywords: biomimetics; building envelope; kinetic building envelope; passive strategies; Thermal comfort

The reservoir network: A new network topology for district heating and cooling

Thermal district networks are effective solutions to substitute fossil fuels with renewable energy sources for heating and cooling. Moreover, thermal networking of buildings allows energy efficiency to be further increased. The waste heat from cooling can be reused for heating in thermal district systems. Because of bidirectional energy flows between prosumers, thermal networks require new hydraulic concepts. In this work, we present a novel network topology for simultaneous heating and cooling: the reservoir network. The reservoir network is robust in operation due to hydraulic decoupling of transfer stations, integrates heat sources and heat sinks at various temperature levels and is flexible in terms of network expansion.We used Modelica simulations to compare the new single-pipe reservoir network to a basecase double-pipe network, taking yearly demand profiles of different building types for heating and cooling. The electric energy consumed by the heat pumps and circulations pumps differs between the reservoir and base case networks by less than 1%. However, if the reservoir network is operated with constant instead of variable mass flow rate, the total electrical consumption can increase by 48% compared to the base case. As with any other network topology, the design and control of such networks is crucial to achieving energy efficient operation.Investment costs for piping and trenching depend on the district layout and dimensioning of the network. If a ring layout is applied in a district, the reservoir network with its single-pipe configuration is more economical than other topologies. For a linear layout, the piping costs are slightly higher for the reservoir network than for the base case because of larger pipe diameters.

Optimization of energy costs for drying ferrocene-containing wastes of winemaking

The paper is devoted to the study of the processes of heat and mass exchange, when drying ferrocene containing wastes of winemaking (FWW), and to the preparation of those wastes to be fed to dairy cattle. The goals of the article are: to determine the amount of energy costs for drying FWW that are necessary for calculating the net cost of feed additives, and to estimate the economic efficiency of the suggested technological and technical solutions; and also to justify and develop the methods for estimating quantitative parameters when removing liquid from the wastes of wine production. Moisture and heat exchange are studied in the “heat agent - drying object” system for convective and infrared drying. A combined method is proposed for drying winemaking waste, to substantiate the sequence of stages and parameters of the process, a graph-analytic model, that is dwelled on the basic principles of convective and infrared drying, is designed. Numerical calculations helped to obtain graphical dependences of the energy costs of the drying process on the air velocity in the drying chamber at different temperatures of the air (for convective and infrared). The model of drying in the form of comparative graphical dependences of the reduced value of the drying speed to the heat flux on the moisture content of the mass subjected to drying is presented. Given the above data, it is recommended to use combined two-phase drying: in the first phase, use infrared radiation, when in the second phase - convective way, in order to reduce the humidity of ferrocene containing winemaking wastes from initial moisture content of 80% to the required value of 18-20% with the further use as neutralizing additives in the feed of dairy cattle. It is also suggested to use the renewable energy sources for heating in order to cut the expenses in the phase of convective drying.

Romania needs a strategy for thermal energy

Abstract The energy sector in Romania consists of three sub-sectors: electricity, natural gas and heat. Among these, the sub-sector of thermal energy is in the most precarious situation because it has been neglected for a long time. This sub-sector is particularly important both due to the amount of final heat consumption (of over 50% of final energy consumption), and to the fact that it has a direct negative effect on the population, industry and services. This paper presents the main directions for developing a modern strategy of the thermal energy sub-sector, which would fit into Romania’s Energy Strategy that is still in preparation This is based on the author’s 50 years of experience in this field that includes knowledge about the processes and the equipment of thermal energy, expertise in the management and restructuring of energy companies and also knowledge of the specific legislation. It is therefore recommended, following the European regulations and practices, the promotion and upgrading of district heating systems using efficient cogeneration, using trigeneration in Romania, modernizing buildings in terms of energy use, using of renewable energy sources for heating, especially biomass, and modernizing the energy consumption of rural settlements.

Investigating a two-component model of solid fuel organic aerosol in London: processes, PM<sub>1</sub> contributions, and seasonality

Abstract. Solid fuel emissions, including those from biomass burning, are increasing in urban areas across the European Union due to rising energy costs and government incentives to use renewable energy sources for heating. In order to help protect human health as well as to improve air quality and pollution abatement strategies, the sources of combustion aerosols, their contributions, and the processes they undergo need to be better understood. A high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) was therefore deployed at an urban background site between January and February 2012 to investigate solid fuel organic aerosols (SFOA) in London. The variability of SFOA was examined and the factors governing the split between the two SFOA factors derived from Positive Matrix Factorisation (PMF) were assessed. The concentrations of both factors were found to increase during the night and during cold periods, consistent with domestic space heating activities. The split between the two factors is likely governed predominantly by differences in burn conditions where SFOA1 best represents more efficient burns and SFOA2 best represents less efficient burns. The differences in efficiency may be due to burner types or burn phase, for example. Different fuel types and levels of atmospheric processing also likely contribute to the two factors. As the mass spectral profile of SFOA is highly variable, the findings from this study may have implications for improving future source apportionment and factorisation analyses. During the winter, SFOA was found to contribute 38% to the total non-refractory submicron organic aerosol (OA) mass, with similar contributions from both SFOA factors (20% from SFOA1 and 18% from SFOA2). A similar contribution of SFOA was derived for the same period from a compact time-of-flight AMS (cToF-AMS), which measured for a full calendar year at the same site. The seasonality of SFOA was investigated using the year-long data set where concentrations were greatest in the autumn and winter. During the summer, SFOA contributed 11% to the organic fraction, where emissions resulted from different anthropogenic activities such as barbecues and domestic garden wood burning. The significant contribution of SFOA to total organic mass throughout the year suggests that the negative effects on health and air quality, as well as climate, are not just confined to winter as exposure to these aerosols and the associated black carbon can also occur during the summer, which may have significant implications for air-quality policies and mitigation strategies.

An Analytical Model for Mathematical Analysis of Smart Daily Energy Management for Air to Water Heat Pumps

Having a substantial and increasing energy demand for domestic heating world wide together with decreasing availability of fossil fuels, the use of renewable energy sources for heating are becoming important. Especially air to water heat pumps have been suggested as an alternative for domestic heating. Using them the main challenge is to be sensitive to the timing of both the outdoor air temperature and the indoor energy demands in order to minimize the energy usage. Such a heating system should work efficiently and economically, thereby also taking into account comfort for the residents, with minimal human intervention. This paper presents an analytical model that can be used to mathematically analyse how to use energy more efficiently with an air to water heat pump. Results of such an analysis have been compared with another, simulation-based approach which has provided more confidence in the model. The model can be integrated in a smart thermostat to obtain more autonomous behavior for indoor heating demands against the changes in outside air temperature over the time.

Experimental evaluation of using various renewable energy sources for heating a greenhouse

The interest in alternative or renewable energy sources for greenhouse heating is currently high, owing to the large heating loads and the relatively high price of fossil fuels. Important alternative sources of energy are solar collectors, heat pumps, biomass and cogeneration systems. This study experimentally investigates greenhouse heating by biogas, solar and ground energy in Elazig, Turkey climate conditions. The greenhouse (6m×4m×2.10m) heated by mentioned alternative energy sources was constructed, and then required heating load of the greenhouse was determined. For this purpose, biogas, solar and a ground source heat pump greenhouse heating system (BSGSHPGHS) with horizontal slinky ground heat exchanger was designed and set up. Experiments were conducted extensively during the winter period from November 2009 to March 2010. During the experiments, 2231.83l of gas production by biogas system is provided. The experiments that are required for the growth of many plants need temperature of 23°C, and conceivable success has been achieved in reaching this value by built systems. As a result, different energy sources have been successfully tested for greenhouse heating.

State Budget Independent, Market-Based Instruments to Finance Renewable Heat Strategies

At present, expanding the use of renewable energy sources for heating (RES-H) relies predominantly on publicly funded support instruments. As these are subject to subsidy cuts and suspensions, these instruments do not provide long-term security for investors and technology suppliers. Although feed-in tariffs and quota-based systems are the major support schemes for renewable energy sources in the electricity sector, similar policy designs have not been applied to RES-H. This paper presents and evaluates three different policy instruments which have the potential to finance RES-H without using public funds: A physical quota system for biomass, a technology-based quota system ( Portfolio Model) and a remuneration-based system ( Premium model). The assessment suggests that while the Portfolio Model and the Premium Model are both promising policies to enhance RES-H deployment, there is greater acceptance among stakeholders for the Premium Model.

Promoting renewable energy sources for heating and cooling in EU-27 countries

In addition to public policies aimed at improving the energy efficiency of buildings, EU authorities have also promoted the use of Renewable Energy Sources for heating and cooling uses (RES H&C). This paper analyses the main policy measures implemented in EU-27 countries up to 2009: i.e. subsidies, tax incentives, financial support and feed-in tariffs. Twenty-three Member States (MSs) have developed some of these policy measures. The most widespread measure is the subsidy (22 MSs have implemented these) because from a political point of view, subsidies provide a straightforward approach to promote the use of RES H&C. Secondly, tax incentives have been used for reducing investment costs and making renewable energy profitable. Thirdly, financial incentives and feed-in tariffs have been used sparingly. While financial incentives might be used more extensively for promoting RES H&C if they are accompanied by other policy measures, feed-in tariffs are not likely to be implemented significantly in the future because this measure is not designed for household heat producers.