scholarly journals Energy saving and optimum insulation thicknesses in building upgrading

2018 ◽  
Vol 240 ◽  
pp. 04007
Author(s):  
Mateusz Orzechowski ◽  
Tadeusz Orzechowski

Heat pumps are classified as ecologically friendly heat-generating devices and are one of the most suitable solutions for improving energy efficiency in buildings. Systems based on such solutions replace conventional sources very well. Household sector is one of the major energy consumers, where energy is used mainly for space heating and providing hot water. To increase renewable energy consumption levels, it is necessary to take decisive actions aimed at energy modernization of existing buildings. Particular emphasis must be put on the use of renewable energy sources. A wide selection of insulation materials is available on the market, however proper technologies are required to apply those materials, especially for historical buildings. Therefore, while planning investment, a question must be answered what type of material should be used, and what costs that will generate. The paper presents simple methodology for calculating the optimal insulation thickness so that the costs of the thermo-modernization would be covered by savings in heating expenses, when bank loan for the project is available at fixed interest rate.

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.


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.


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 (2) ◽  
pp. 332
Author(s):  
Janusz Grabara ◽  
Arsen Tleppayev ◽  
Malika Dabylova ◽  
Leonardus W. W. Mihardjo ◽  
Zdzisława Dacko-Pikiewicz

In this contemporary era, environmental problems spread at different levels in all countries of the world. Economic growth does not just depend on prioritizing the environment or improving the environmental situation. If the foreign direct investment is directed to the polluting industries, they will increase pollution and damage the environment. The purpose of the study is to consider the relationship between foreign direct investment in Kazakhstan and Uzbekistan and economic growth and renewable energy consumption. The study is based on data obtained from 1992 to 2018. The results show that there is a two-way link between foreign direct investment and renewable energy consumption in the considered two countries. The Granger causality test approach is applied to explore the causal relationship between the variables. The Johansen co-integration test approach is also employed to test for a relationship. The empirical results verify the existence of co-integration between the series. The main factors influencing renewable energy are economic growth and electricity consumption. To reduce dependence on fuel-based energy sources, Kazakhstan and Uzbekistan need to attract energy to renewable energy sources and implement energy efficiency based on rapid progress. This is because renewable energy sources play the role of an engine that stimulates the production process in the economy for all countries.


Smart Cities ◽  
2019 ◽  
Vol 2 (4) ◽  
pp. 471-495
Author(s):  
Viktor Stepaniuk ◽  
Jayakrishnan Pillai ◽  
Birgitte Bak-Jensen ◽  
Sanjeevikumar Padmanaban

The smart active residential buildings play a vital role to realize intelligent energy systems by harnessing energy flexibility from loads and storage units. This is imperative to integrate higher proportions of variable renewable energy generation and implement economically attractive demand-side participation schemes. The purpose of this paper is to develop an energy management scheme for smart sustainable buildings and analyze its efficacy when subjected to variable generation, energy storage management, and flexible demand control. This work estimate the flexibility range that can be reached utilizing deferrable/controllable energy system units such as heat pump (HP) in combination with on-site renewable energy sources (RESs), namely photovoltaic (PV) panels and wind turbine (WT), and in-house thermal and electric energy storages, namely hot water storage tank (HWST) and electric battery as back up units. A detailed HP model in combination with the storage tank is developed that accounts for thermal comforts and requirements, and defrost mode. Data analytics is applied to generate demand and generation profiles, and a hybrid energy management and a HP control algorithm is developed in this work. This is to integrate all active components of a building within a single complex-set of energy management solution to be able to apply demand response (DR) signals, as well as to execute all necessary computation and evaluation. Different capacity scenarios of the HWST and battery are used to prioritize the maximum use of renewable energy and consumer comfort preferences. A flexibility range of 22.3% is achieved for the scenario with the largest HWST considered without a battery, while 10.1% in the worst-case scenario with the smallest HWST considered and the largest battery. The results show that the active management and scheduling scheme developed to combine and prioritize thermal, electrical and storage units in buildings is essential to be studied to demonstrate the adequacy of sustainable energy buildings.


Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 5119
Author(s):  
Tomasz Sliwa ◽  
Tomasz Kowalski ◽  
Dominik Cekus ◽  
Aneta Sapińska-Śliwa

Currently, renewable energy is increasingly important in the energy sector. One of the so-called renewable energy sources is geothermal energy. The most popular solution implemented by both small and large customers is the consumption of low-temperature geothermal energy using borehole heat exchanger (BHE) systems assisted by geothermal heat pumps. Such an installation can operate regardless of geological conditions, which makes it extremely universal. Borehole heat exchangers are the most important elements of this system, as their design determines the efficiency of the entire heating or heating-and-cooling system. Filling/sealing slurry is amongst the crucial structural elements. In borehole exchangers, reaching the highest possible thermal conductivity of the cement slurry endeavors to improve heat transfer between the rock mass and the heat carrier. The article presents a proposed design for such a sealing slurry. Powdered magnesium was used as an additive to the cement. The approximate cost of powdered magnesium is PLN 70–90 per kg (EUR 15–20/kg). Six different slurry formulations were tested. Magnesium flakes were used in designs A, B, C, and magnesium shavings in D, E and F. The samples differed in the powdered magnesium content BWOC (by weight of cement). The parameters of fresh and hardened sealing slurries were tested, focusing mainly on the thermal conductivity parameter. The highest thermal conductivity values were obtained in design C with the 45% addition of magnesium flakes BWOC.


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).


2018 ◽  
Vol 4 (7) ◽  
Author(s):  
Andrijana Stevanović ◽  
Boban Jolović

One of the most used renewable energy sources worldwide is geothermal energy. Itrepresents the heat, originated by natural processes happen in the Earth interior. The hot springsphenomena are the most frequent natural manifestation of geothermal activity.Geothermal potentiality of some area can be estimated based on geothermal gradient. Geothermalgradient is a conductive terrestrial parameter that represents the degree of increasing of the Earthtemperature vs. depth. It is usually expressed in ⁰C/m or ⁰C/km. Different areas have differentthermal gradients and thus different geothermal potential. Generally, higher geothermal gradientscorrespond to areas containing more geothermal energy.Geothermal characteristics of the territory of the Republic of Srpska are closely related to itscomplex geological setting. It is the reason why geothermal characteristics are different from areato area. Higher geothermal potentiality is recognised in the northern parts of the entity, in the firstorder in Semberija, Posavina and Banja Luka regions.The use of geothermal energy with different fluid temperatures can be considered throughthe Lindaldiagram, who firstly proposed acomprehensive scale with appropriate temperatures for differentuses. High temperature fluids are mostly used for electricity production and moderate and lowtemperature fluids for the direct use.Despite the fact that the territory of the Republic of Srpska hasfavourable geothermal properties, utilization of this kind of renewable energy resource isinadequate. Especially indicative are data about the use of geothermal energy by heat pumps (inbad sense) in comparison with praxis of developed countries.Chemical composition of thermal waters plays very important role and can be used in itsexploration stage, for analyses of possibility of its use and for prediction of exploitation effects, aswell. This kind of renewable energyresource, highly ecologically recommended, must be consideredmore seriously in the future in the Republic of Srpska. Furthermore, it must be put into the energystrategic documentsin appropriate manner.


Author(s):  
Özlem Karadağ Albayrak

Making the use of renewable energy sources widespread is of paramount importance for Turkey as for all countries. In this regard, the determiners of renewable energy consumption have been investigated. The effect of determining or factors affecting the use of renewable energy sources on a regional scale to Turkey were examined with different qualitative and quantitative research techniques. In this study, the factors of economic growth, public investments, and population are analyzed by considering regional differences on the consumption of renewable energy resources. The effect of regional economic growth, regional public investments, and regional population on the amount of regional renewable energy consumption were investigated by using panel data of 26 statistical regions of Level-2 classification in the period between 2010-2018 in Turkey. The results obtained by the dynamic panel data analysis concluded that economic growth and public investments at the regional level increased renewable energy consumption while the population growth decreased.


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