scholarly journals Comparative Thermo-energetic Analysis of the District Heating Systems that Harness Renewable Energy Sources

2017 ◽  
Vol 181 ◽  
pp. 754-761 ◽  
Author(s):  
Teodora-Melania Şoimoşan ◽  
Raluca-Andreea Felseghi
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.


Energies ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 5151 ◽  
Author(s):  
Ieva Pakere ◽  
Dace Lauka ◽  
Dagnija Blumberga

The main aim of this study is to evaluate the results achieved by implementation of different support policies in form of subsidies for energy efficiency improvements and transition to renewable energy sources. The article compares the energy efficiency measures in district heating systems with other support program. In order to assess the effectiveness of implementation of different renewable energy technologies and energy efficiency projects, the levelized costs of saved energy for different support programs were determined. Authors compared different co-financed projects related to replacement of fossil fuel energy sources in district heating (mainly to biomass) and the installation of new biomass boilers, heat pumps, solar collectors and other local technologies in municipal buildings. Results show that financial support for energy efficiency measures in industrial enterprises and district heating systems has been most cost-effective, mainly due to the low co-financing rate (30%) and the high potential for energy savings in different production processes. Authors have identified the blind-spots within the funding allocation for different municipalities, which is not always dedicated to achieved energy savings.


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.


2021 ◽  
Author(s):  
Marija Živković ◽  
Dejan Ivezic

Abstract Transformation of the heating sector is recognized as being essential for ensuring reliable and affordable energy services provided with reduced consumption of energy sources, diminished impact on the environment and less import dependency. The possibility of utilizing energy sources that otherwise would be wasted needs to be considered and treated as a big advantage of district heating systems. Despite many advantages, sewage wastewater heat is still a mostly unused resource at the global level and a totally unused energy source in Serbia, while data about the potential of this energy source are lacking. This research proposes a methodology for the determination of the technical potential of waste heat from wastewater treatment facilities for use in district heating systems by heat pump application. Data from existing wastewater treatment facilities are used for providing data for replication in cities without wastewater treatment plants but with district heating systems. An estimation of the recoverable heat energy potential of wastewater is used for evaluation of some effects that could be obtained through its full utilization for heat production in the existing district heating systems. Three groups of indicators are selected for analysis focusing on district heating systems' energy performance (primary energy factor, specific heat consumption per degree day and heating area), the security of energy supply (import dependency, Shannon Wiener diversification index, the share of renewables) and environmental impact (carbon dioxide emission coefficient). Values of the selected indicators are determined for the current state of district heating systems and for the possible future state that could be achieved after full utilization of sewage wastewater potential. The proposed methodology is applied to Serbia, as a case study. It has been shown that all analyzed indicators for the projected future would have more preferable values compared to the values that correspond to the current state of the district heating systems. The use of this renewable energy source should provide primary energy savings of 5% per year, reduction of carbon dioxide emission of 6.5% per year, reduction of import dependency of DH systems of 9.8% and improved diversification of energy sources of 21%.


Author(s):  
Anatolijs Borodinecs ◽  
Raimonds Bogdanovics ◽  
Aleksejs Prozuments ◽  
Jelena Tihana ◽  
Baiba Gaujena

2019 ◽  
Vol 9 (1) ◽  
pp. 269-281
Author(s):  
Wojciech Drozd ◽  
Marcin Kowalik

AbstractThe article presents the most frequently chosen heating systems for single-family houses and utility water heating by investors. The most popular installations based on conventional fuels using renewable energy sources were compared. A technical and cost analysis of the adopted cases was carried out. Finally, the most important conclusions resulting from the analys is were given. The article is mainly intended to encourage the reader - the investor to be to choose pro-ecological solutions based on modern technology that guarantees comfortable use and limited environmental pollution. The authors wanted to achieve the intended goal by presenting available heating systems and performing an in-depth analysis, after which the obtained results would be similar to the real situation.


2017 ◽  
Vol 35 (7) ◽  
pp. 1218-1241 ◽  
Author(s):  
Frede Hvelplund ◽  
Søren Djørup

Transition from the stored energy of fossil fuel-based systems to fluctuating renewable energy sources requires a fundamental change in both the energy supply system and governance arrangements. According to analyses made using the Aalborg University Energy PLAN model, the infrastructure required to handle fluctuating energy – such as goals for further expanding the exploitation of wind power towards 50% of energy consumption – necessitates the integration of power, district heating, transportation and biomass production, which should be geographically distributed. To enhance our understanding of this paradigmatic technological change, this article presents both a general analysis of the regulatory consequences and a specific analysis of the immediate challenges involved in the transition process, framed within the Danish context. The general conclusion is that the required distributed, local and regional technological energy system needs a bottom up and interactive regulatory framework, where the central government should have a more reflexive and communicative role, providing services and national coordination for an energy system that contains a large share of fluctuating renewable energy sources. A specific conclusion is that the present Danish tariff principles and energy tax system should be fundamentally altered in order to better facilitate the coordination of the heat and electricity sectors, to incentivise the creation of the necessary integration infrastructure.


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