scholarly journals The Advisability of Employment of Renewable Energy Sources in DHW Systems in the Kindergarten

Proceedings ◽  
2019 ◽  
Vol 16 (1) ◽  
pp. 41
Author(s):  
Dorota Anna Krawczyk ◽  
Antonio Rodero ◽  
Agata Witkowska ◽  
Bernadetta Wądołowska

This research aims to show the advisability of usage of selected renewable energy sources for domestic hot water (DHW) installations in buildings located in Poland and Spain. The analysis was conducted for a typical kindergarten, an example of buildings with high density of people and stable profile of usage, as opposed to schools which are closed during summer holidays. We took into account national regulations to estimate heat demand. Then applying solar collectors and heat pumps to use as a monovalent energy sources were considered. The total cost of the system with solar collectors in Poland was found to be 1.4 times higher than in Spain, whereas the difference in a case of air heat pumps was 18%. Moreover efficiency of solar collector and heat pump systems were found as 49.56% for Warsaw, 52.29% for Madrid with coefficient of performance (COP) 2.2 and 2.55 respectively, therefore simple payback time (SPBT) of investment was estimated in a range between 6–12 years for solar collectors and 5–6 years for heat pumps.

2019 ◽  
Vol 116 ◽  
pp. 00084
Author(s):  
Krystian Szczerbak

The climate in Poland is slightly disparate in each region. The differences in temperature not always come along with the intensity of solar radiation in 5 climate zones. South of the country is colder, but well irradiated by the Sun and northern regions have milder climate, but are less irradiated. This fact alone makes people consider the suitability and safety of using renewable energy sources such as air-to-water heat pumps, solar collectors and photovoltaics instead of more traditional, fossil fuel powered sources. This paper presents a comparison analysis of energy demand and the cost for heating in a group of single-family buildings by 4 variants (gas boiler, gas boiler and solar collectors, air-to-water heat pump, air-to-water heat pump and photovoltaics) in 5 chosen cities in each polish climate zone. Calculations were done for space heating and domestic hot water energy demand, CO2 emissions and cumulative costs for all variants and locations. The results confirm the inconsistency of polish climate and have shown profitability and utility of renewable energy sources.


2019 ◽  
Vol 3 (2) ◽  

In the recent attempts to stimulate alternative energy sources for heating and cooling of buildings, emphasise has been put on utilisation of the ambient energy from ground source heat pump systems (GSHPs) and other renewable energy sources. Exploitation of renewable energy sources and particularly ground heat in buildings can significantly contribute towards reducing dependency on fossil fuels. The study was carried out at the Energy Research Institute (ERI), between September 2016 and November 2017. This paper highlights the potential energy saving that could be achieved through use of ground energy source. The main concept of this technology is that it uses the lower temperature of the ground (approximately <32°C), which remains relatively stable throughout the year, to provide space heating, cooling and domestic hot water inside the building area. The purpose of this study, however, is to examine the means of reducing of energy consumption in buildings, identifying GSHPs as an environmental friendly technology able to provide efficient utilisation of energy in the buildings sector, promoting the use of GSHPs applications as an optimum means of heating and cooling, and presenting typical applications and recent advances of the DX GSHPs. It is concluded that the direct expansion of GSHP are extendable to more comprehensive applications combined with the ground heat exchanger in foundation piles and the seasonal thermal energy storage from solar thermal collectors. This study highlights the energy problem and the possible saving that can be achieved through the use of the GSHP systems. This article discusses the principle of the ground source energy, varieties of GSHPs, and various developments.


Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 2971
Author(s):  
Rok Koželj ◽  
Eneja Osterman ◽  
Fabrizio Leonforte ◽  
Claudio Del Pero ◽  
Alessandro Miglioli ◽  
...  

When considering the deployment of renewable energy sources in systems, the challenge of their utilization comes from their time instability when a mismatch between production and demand occurs. With the integration of thermal storages into systems that utilize renewable energy sources, such mismatch can be evened out. The use of phase-change materials (PCMs) as thermal storage has a theoretical advantage over the sensible one because of their high latent heat that is released or accumulated during the phase-change process. Therefore, the present paper is a review of latent thermal storages in hydronic systems for heating, cooling and domestic hot water in buildings. The work aims to offer an overview on applications of latent thermal storages coupled with heat pumps and solar collectors. The review shows that phase-change materials improve the release of heat from thermal storage and can supply heat or cold at a desired temperature level for longer time periods. The PCM review ends with the results from one of the Horizon2020 research projects, where indirect electrical storage in the form of thermal storage is considered. The review is a technological outline of the current state-of-the-art technology that could serve as a knowledge base for the practical implementation of latent thermal storages. The paper ends with an overview of energy storage maturity and the objectives from different roadmaps of European bodies.


Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3183
Author(s):  
Michaela Makešová ◽  
Michaela Valentová

Reaching climate neutrality by 2050 is one of the main long-term objectives of the European Union climate and energy policy, and renewable energy sources (RES) are integral parts of this transition. RES development results in many effects, direct and indirect, linked to each other, societal, local and individual, i.e., “multiple impacts of RES” (MI RES). These effects need to be carefully assessed and evaluated to obtain the full picture of energy field transformation and its context, and enable further development of RES. Nevertheless, the MI RES concept is often presented misleadingly and its scope varies throughout the literature. This paper provides a literature overview of the methodologies of this concept and presents a new concept of MI RES, respecting the difference between effects resulting from the implementation of RES and ultimate multiple impacts. We have summarized the effects into four groups: economic, social, environmental, and technical, which all lead to group of ultimate multiple impacts. Finally, we provide the complex overview of all MI RES and present the framework, which is used to analyze the multiple impacts and effects of RES and to show how the RES development leads and contributes to these impacts and effects. The concept is recommended to be considered in designing a robust energy policy by decision-makers.


2018 ◽  
Vol 18(33) (4) ◽  
pp. 250-258
Author(s):  
Anna Klepacka

The aim of this article was to show the position of Poland in the renewable energy subsectors among the European Union countries. The research covered the areas of biomass, solar heating and heat pumps, showing the degree of their utilization, power required to drive the system and their production in 2016. The provided information was supplemented with a revenues per employee in thousand euros in chosen subsectors of renewable energy sources in the year 2016. The main tool for carrying out the set objective was the use of descriptive and comparative methods. The results of the survey demonstrated Poland’s prominent place in the sector of liquid biofuels (1st place in EU), thanks to the significant supply of raw materials as well as development perspectives in solar energy, which is confirmed by the world's statistics indicating a record number of photovoltaic installations fitted (PV).


Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1136 ◽  
Author(s):  
Nikolaos Sifakis ◽  
Tryfon Daras ◽  
Theocharis Tsoutsos

In this paper is provided a systematic, in-depth, behavioral analysis of renewable energy sources cooperatives’ members. The analysis proved that in, on hand, there was a noticeable difference in the portion of affection of each proposed intervention on the actual energy consumption, which may be to even ten times more in some cases, and on the other hand, the difference in energy consumption between the analyzed groups was noticeable as well. So, implementing energy efficiency interventions of various types, such as technical support, special tariffs, energy generation schemes, and smart meters, seems to lead to substantial energy reductions to even more than 10%, cumulatively, and reduces the environmental footprint. Additionally, the majority of energy efficiency interventions applied by the renewable energy sources cooperatives are proved to be effective in achieving their primary goal, sensitizing members, and leading them to a more efficient energy consumption behavior (“greener”). The results of the analysis showed that each proposed intervention had played a different but nonetheless significant role in the diminishing of the energy consumption of the members and that there was a noticeable difference in energy consumption between the analyzed groups. The results of the analysis demonstrated more than 22 GWh totally in green consumption, and almost 4500 tons of CO2 saved.


2014 ◽  
Vol 658 ◽  
pp. 35-40 ◽  
Author(s):  
Daniela Ciobanu ◽  
Codruta Jaliu ◽  
Radu Saulescu

The use of renewable energy sources represents a continuous concern for the researchers around the world. The main source of renewable energy, the sun can be used for producing hot water / heating or electric energy, by means of solar collectors. The concentrating solar collectors contain tracking systems for orientation on one or two axes. The tracking system for the elevation motion has to ensure a reduced angular stroke. The mechanism that is usually included in the system structure is of linkage type, being driven by a linear actuator. The mechanism has the advantages of low complexity and reduced cost. In the case of diurnal motion, the angular stroke is larger, being usually obtained with gears or chain drives. The actuation is achieved by motor-reducers with high transmission ratios and costs. In order to reduce the costs, mechanisms containing linkages driven by linear actuators are proposed in literature. These tracking systems have the disadvantage of large overall dimensions. To reduce this disadvantage, the paper proposes a new variant of chain tracking system driven by a linear actuator. Then the proposed tracking system is structurally optimized, process that generates 6 new variants of mechanisms. These solutions eliminate the problems created by the hyperstatical constraints and avoid blocking in case of assembling errors.


2021 ◽  
Vol 295 ◽  
pp. 04005
Author(s):  
Sergey Batukhtin ◽  
Andrey Batukhtin ◽  
Marina Baranovskaya

According to experts’ forecasts, by 2040 the global demand for energy will increase by 37%, and renewable energy sources in the next 20 years will become the fastest growing segment of the world energy, their share in the next decade will grow by about one and a half times. Solar energy is the fastest growing industry among all non-conventional energy sources and is gaining the highest rates of development in comparison with other renewable energy sources. In this article, the authors provide an overview of the technologies that increase the efficiency and productivity of solar panels, only the investigated methods are described that can speed up the process of introducing solar energy instead of traditional. All the methods described can increase the efficiency of systems that are based on the use of the sun as the main source of energy. The authors presented and described the scheme of a solar-air thermal power plant, which will improve energy efficiency through the use of a regenerative air solar collector with increased heat transfer efficiency. Strengthening will be achieved through the use of hemispherical depressions on the surface that receives solar radiation. A schematic diagram is given and the principle of operation of such a solar collector is described in detail. A comparative calculation of the intensification of the solar collector with the use of depressions and without the use as modernization was carried out, on the basis of which a conclusion was made about the efficiency of using this type of solar collector and the economic effect from the application of this method. A description of the method for calculating the solar collector is given, thanks to which this development can be used and implemented in existing heating and hot water supply systems.


2021 ◽  
Vol 2130 (1) ◽  
pp. 012004
Author(s):  
M J Geca

Abstract The paper presents a model of a self-service car wash. Sub-models of water, electricity and natural gas consumption were developed. Heated water is used to wash vehicles and in winter to heat the floor. Electricity is mainly used to power high pressure pumps. The data to develop submodels were based on a time series of 1 year from a 5-station car wash located in central Poland. Chemical consumption and costs were not analyzed in this paper. Generally, this data is quite difficult to access and not provided by car wash manufacturers or owners. The developed model allowed estimating the possibility of using renewable energy sources in the form of solar collectors and photovoltaic panels to balance the energy demand of a car wash depending on the number of washing stands and car wash load. Application of solar collectors allows saving 334 m3 of natural gas per year and 11.2 MWh of electricity in the case of applying photovoltaic panels. The amount of electricity consumed by the carwash is so large that mounting the panels on the whole available area will not provide the required amount anyway. Installation of photovoltaic installation on the premises of touchless car wash is justified in the case of connecting the installation to the public network, which was treated as a battery. The cost of maintaining such a battery is 20% of each stored kWh. As a result of the applied solutions, the CO2 emission will be reduced.


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