scholarly journals Hybrid solar-biomass system for district heating

2019 ◽  
Vol 85 ◽  
pp. 04006
Author(s):  
Adrian Ilie ◽  
Ion Vişa

The energy used in the built-up environment represents at least 40% of the total energy consumed, out of which, at least 60% is required for heating, cooling and domestic hot water (DHW). Within the European Union, more than 6,000 communities (i.e. over 9%) use district heating systems, the majority of which use the conversion of fossil fuels as a source of energy. This aspect, which is corroborated by the directives of the EU legislation on the use of renewable energy sources and energy performance, imposes the development of new solutions through which the existing district heating systems may be adapted to use renewable energy sources. The solar-thermal systems that are used on a large (district) scale are becoming more and more efficient from the point of view of their feasibility; however, it is almost impossible to create systems that should satisfy the thermal energy demand throughout the four seasons of the year. The hybrid solar-biomass system is becoming the applicable solution for the majority of the communities that have from this potential, since it can secure independence from the point of view of the use of thermal energy. This paper presents the design stages for the implementation of the hybrid solar-biomass systems with a view to identifying the optimal solutions for systems to be integrated into an existing district heating system. A case study (Taberei District in Odorheiu Secuiesc City), which provides a detailed description of the feasible technical solutions, is presented.

2018 ◽  
Vol 30 ◽  
pp. 03001
Author(s):  
Maciej Knapik

The article presents an economic analysis and comparison of selected (district heating, natural gas, heat pump with renewable energy sources) methods for the preparation of domestic hot water in a building with low energy demand. In buildings of this type increased demand of energy for domestic hot water preparation in relation to the total energy demand can be observed. As a result, the proposed solutions allow to further lower energy demand by using the renewable energy sources. This article presents the results of numerical analysis and calculations performed mainly in MATLAB software, based on typical meteorological years. The results showed that system with heat pump and renewable energy sources Is comparable with district heating system.


2021 ◽  
Vol 13 (10) ◽  
pp. 5442
Author(s):  
Beatriz María Paredes-Sánchez ◽  
José Pablo Paredes ◽  
Natalia Caparrini ◽  
Elena Rivo-López

District heating and cooling (DHC) systems play an important role under the new European Union (EU) energy transition strategy. Thermal energy networks are helping to stimulate the development of alternative technologies based on a broad range of renewable energy sources. The present study analysed the current situation of DHC systems in Spain and provides an overview of the challenges and future opportunities that their use will entail. Its objective is to assess thermal energy conversion and management from a holistic perspective, including a study of existing energy infrastructures. The focus of this study lies on Spain given the country’s abundance of natural resources such as renewable energy sources including solar energy, biomass and geothermal energy, among others, as well as its strategic location on the map of the EU. Based on the analysis of the three factors for energy conversion in a district heating system, namely resources, technology, and management, the methodology provided an assessment of the different factors involved in running a DHC system. The results show an estimated total production for DHC networks of 1448 MWth, of which 72% is supplied purely by renewable energy sources.


Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3218
Author(s):  
Pedro Durán ◽  
Herena Torio ◽  
Patrik Schönfeldt ◽  
Peter Klement ◽  
Benedikt Hanke ◽  
...  

There are 1454 district heating systems in Germany. Most of them are fossil based and with high temperature levels, which is neither efficient nor sustainable and needs to be changed for reaching the 2050 climate goals. In this paper, we present a case study for transforming a high to low temperature district heating system which is more suitable for renewable energy supply. With the Carnot Toolbox, a dynamic model of a potential district heating system is simulated and then transformed to a low temperature supply. A sensitivity analysis is carried out to see the system performance in case space constrains restrict the transformation. Finally, an economic comparison is performed. Results show that it is technically possible to perform the transformation until a very low temperature system. The use of decentralized renewable sources, decentralized heat storage tanks and the placement of a heat pump on each building are the key points to achieve the transformation. Regarding the sensitivity analysis, the transformation is worth doing until the seasonal storage and solar collector field sizes are reduced to 60% and 80% of their values in the reference case, respectively. The economic analysis shows, however, that it is hard for highly efficient low temperature renewable based heat networks to compete with district heating systems based on a centralized fossile CHP solution. Thus, though the presented transformation is technically possible, there is a strong need to change existing economic schemes and policies for fostering a stronger promotion of renewable energy policies in the heat sector.


Author(s):  
Vaidas Bondzinskas ◽  
Jurgita Mačiulytė

Bio-fuel, used for production of thermal energy, is one of the most important renewable energy sources in Lithuania. The use of this energy source is determined by Lithuania‘s commitments to the European Union and the energetic policy carried out by the state, which encourages the use and replenishment of renewable energy sources. The article consists of three parts, which analyze the teritorial distribution of potential biofuel resources, i.e. short-rotation energy crops, realized forest products in Lithuania‘s forestry enterprises, and use of bio-fuel for production of thermal energy for Lithuania‘s centralized heating systems in 2012.


2021 ◽  
Vol 2021 (1) ◽  
pp. 52-59
Author(s):  
V.O. Derii ◽  

We considered trends in the development of district heating systems (DHS) in Europe and Ukraine. It was established that DHS are widely used and make a significant contribution to the heat supply of European countries. In the European Union as a whole, the share of DHS is 13%, and there are plans to increase it to 50% in 2050 with a wide use of cogeneration and renewable sources of energy, including environmental energy with using heat pumps. Ukraine is one of the countries with a high level of DHS, but, at present, there are negative trends to reducing their contribution to the total heat supply for heating and hot water supply – from 65.2% in 2014 to 52% in 2017. In several cities, DHS ceased to function at all. The main equipment of the DHS of Ukraine is physically worn out and technologically obsolete and needs to be renewed by means of wide reconstruction, modernization, and technological re-equipment. We determined factors and the level of their influence on the demand in thermal energy of DHS. It was established that the factors reducing demand have a much greater potential. We created forecasts of demand for thermal energy, fuel balance, and the structure of DHS generation by 2050. It is shown that the demand for thermal energy from DHS will decrease and reach about 35 million Gcal in 2050. To ensure the low-carbon development of Ukraine in the structure of thermal energy generation in DHS, the use of coal-fired CHPs and boilers, as well as boilers on petroleum products will be significantly reduced. The share of natural gas in the fuel balance of DHS of Ukraine will also decrease, but it will be the main fuel for the period of technological transformation of generating capacities under conditions of the low-carbon development of Ukraine. The use of technologies for the production of thermal energy from biomass, waste, environment, and electricity will gradually increase, and in 2050, using these sources will produce about 23.8 million Gcal, which is more than 60% of the total thermal energy of DHS. Keywords: district heating systems, thermal energy, factors of influence, demand, fuel balance, generation structure


2020 ◽  
Vol 4 (1) ◽  
pp. 28-34
Author(s):  

Many traditional heating systems based on fossils face challenges such as lack of investment or unfavorable price regulation, low technical performance, impact on the environment and negative consumer perceptions. The CoolHeating project funded by the EU’s Horizon 2020 program, whose basic features and outcomes are presented in this work, promotes the implementation of small modular renewable heating and cooling grids for communities in South-Eastern Europe, including the town of Visoko as one of five target regions. Core activities, besides techno-economical assessments and social-environmental benefits, include measures to stimulate the interest of communities and citizens to set-up renewable district heating systems. In this work, an analysis was performed for implementation of small modular district heating system in Visoko, covering several public buildings and few neighborhoods in north-western part of town. Combination of different renewable energy sources were analyzed leading to an optimal and a very promising energy supply strategy due to its contribution to security of supply, financial stability, local economic development, local employment, etc. Possible financial savings for heating of 38% compared to current financial needs are determined. Structure optimization of solar collector holders was also performed, taking into account external influence, enabling savings in the structure material. This approach confirms feasibility of transition from traditional to renewable energy based heating system. Having in mind the modularity of such systems, similar solutions can be replicated in other South-Eastern European cities and other countries.


Energies ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5984
Author(s):  
Hanna Jędrzejuk ◽  
Dorota Chwieduk

This paper analyses possibilities of refurbishment of Warsaw’s residential buildings towards standards of the Positive Energy District. The annual final energy consumption in the city in 2019 for the district heating was 8668 GWh, gas (pipelines) was 5300 GWh, electricity from the grid was 7500 GWh, while the emission of the carbon dioxide was 5.62 × 109 kg. The city consists of 18 districts, which are heterogeneous in terms of typology and structure of buildings. The great variety of buildings can be seen, for example, by the annual final energy demand for space heating and hot water preparation per unit of room area. This annual index ranges from over 400 kWh/m2 in historic buildings to 60 kWh/m2 in modern buildings. A reduction in the consumption of non-renewable energy sources and carbon dioxide emissions can be achieved by improving the energy standard of residential buildings and by using renewable energy sources: solar energy, geothermal energy and biogas. The potential barriers for achieving the status of a positive energy district, for example, problems connected with ownership, financing new investments and refurbishment and legal boundaries, have been identified. Moreover, changing the existing electrical grid and district heating systems in urban areas in Warsaw requires comprehensive modernization of practically the entire city’s infrastructure.


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