scholarly journals The choice of appropriate generator systems to enhance the renewable energy share in buildings. A comparison between PV-assisted heat pumps and biomass boilers

2021 ◽  
Vol 312 ◽  
pp. 02014
Author(s):  
Roberto Bruno ◽  
Piero Bevilacqua ◽  
Stefania Perrella ◽  
Daniela Cirone ◽  
Natale Arcuri
Keyword(s):  
Renewable Energy ◽  
Building Energy ◽  
Primary Energy ◽  
Heat Pumps ◽  
Dynamic Simulations ◽  
Climatic Zones ◽  
Energy Demands ◽  
Certification Procedure ◽  
Low Energy Buildings ◽  
Energy Share

Low-energy buildings are generally equipped with generation systems driven by renewable sources. Regarding heating and DHW production, two choices appear appropriate: PV assisted heat pumps and biomass boilers. In this paper, by means of TRNSYS dynamic simulations, the non-renewable primary energy was determined for two buildings located in different climatic contexts by varying the PV size to consider the actual self-consumed electricity of commercial devices. Results showed that in cold climates biomass boilers are more suggested, especially in unfavourable climatic zones, whereas the COP of air-water heat pumps is strongly penalized by the outdoor temperatures and in many cases the self-consumed PV electricity does not limit the grid intervention adequately. However, in building with limited thermal energy demands and in favorable climates, suitable PV sizes make heat pumps more performant than biomass boilers. The same calculations were conducted with the quasi-steady approach, in accordance with the Italian building energy certification procedure, observing a favorable scenario in a heating plant equipped with a PV assisted heat pump because it assumes the renewable electricity entirely absorbed, while the accounting of the actual self-consumed share produces a greater demand of non-renewable energy.

Sustainable energy solutions for thermal load in buildings - Role of heat pumps, solar thermal, and hydrogen-based cogeneration systems

2021 ◽  
pp. 1-25
Author(s):  
Praveen Cheekatamarla ◽  
Vishaldeep Sharma ◽  
Bo Shen
Keyword(s):  
Energy Efficiency ◽  
Renewable Energy ◽  
Carbon Footprint ◽  
Energy Demand ◽  
Primary Energy ◽  
Heat Pumps ◽  
Total Carbon ◽  
Coefficient Of Performance ◽  
Renewable Energy Resources ◽  
The Impact

Abstract Economic and population growth is leading to increased energy demand across all sectors – buildings, transportation, and industry. Adoption of new energy consumers such as electric vehicles could further increase this growth. Sensible utilization of clean renewable energy resources is necessary to sustain this growth. Thermal needs in a building pose a significant challenge to the energy infrastructure. Supporting the current and future building thermal energy needs to offset the total electric demand while lowering the carbon footprint and enhancing the grid flexibility is presented in this study. Performance assessment of heat pumps, renewable energy, non-fossil fuel-based cogeneration systems, and their hybrid configurations was conducted. The impact of design configuration, coefficient of performance (COP), electric grid's primary energy efficiency on the key attributes of total carbon footprint, life cycle costs, operational energy savings, and site-specific primary energy efficiency are analyzed and discussed in detail.

scholarly journals The possibility of achievement of the nZEB state of a refurbished detached house powered solely by renewable energy sources in Southern Poland

2018 ◽  
Vol 70 ◽  
pp. 01001
Author(s):  
Jacek Biskupski
Keyword(s):  
Renewable Energy ◽  
Energy Demand ◽  
Renewable Energy Sources ◽  
Primary Energy ◽  
Heat Pumps ◽  
Space Heating ◽  
Zero Energy ◽  
Electricity Grid ◽  
Primary Energy Demand ◽  
Pv Generator

This paper gives a thorough description of the two different scenarios of retrofit of an existing detached country house (with high primary energy demand) to a net zero energy building (nZEB) or near zero energy (nearZEB) by using energy form on-site RES. Using a designed piece of modelling software author pointed out two possible solutions. First one, based on a bio boiler and small on-site PV generator (on-grid) and the other based on large PV generator and three heat pumps. A 24 months test was performed in order to find out the output of both scenarios. In first period, the bio boiler delivered energy for space heating and DHW, while energy from PV was used to cover all electricity needs of the household during the 12 months testing period. In the later, the energy received from 10 kWp PV of was partly used to cover the current needs of the entire household (switchable on/off-grid system), and surplus was stored in the national electricity grid and regained later in the winter for the space heating (by a GSHP) and ventilation (ASHP) and DHW (dedicated ASHP). In both cases the system proofed the possibility to achieve the nZEB (nearZEB in first scenario) state of the household, as all (in the first near all) energy needs were covered by renewable energy produced on-site.

scholarly journals Synthesis and Optimal Operation of Smart Microgrids Serving a Cluster of Buildings on a Campus with Centralized and Distributed Hybrid Renewable Energy Units

Energies ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 745 ◽  
Author(s):  
Daniele Testi ◽  
Paolo Conti ◽  
Eva Schito ◽  
Luca Urbanucci ◽  
Francesco D’Ettorre
Keyword(s):  
Renewable Energy ◽  
Combustion Engine ◽  
District Heating ◽  
Energy System ◽  
Primary Energy ◽  
Heat Pumps ◽  
Optimal Operation ◽  
Optimal Control Strategy ◽  
Renewable Energy Technologies ◽  
Energy Technologies

Micro-district heating networks based on cogeneration plants and renewable energy technologies are considered efficient, viable and environmentally-friendly solutions to realizing smart multi-energy microgrids. Nonetheless, the energy production from renewable sources is intermittent and stochastic, and cogeneration units are characterized by fixed power-to-heat ratios, which are incompatible with fluctuating thermal and electric demands. These drawbacks can be partially overcome by smart operational controls that are capable of maximizing the energy system performance. Moreover, electrically driven heat pumps may add flexibility to the system, by shifting thermal loads into electric loads. In this paper, a novel configuration for smart multi-energy microgrids, which combines centralized and distributed energy units is proposed. A centralized cogeneration system, consisting of an internal combustion engine is connected to a micro-district heating network. Distributed electric heat pumps assist the thermal production at the building level, giving operational flexibility to the system and supporting the integration of renewable energy technologies, i.e., wind turbines, photovoltaic panels, and solar thermal collectors. The proposed configuration was tested in a hypothetical case study, namely, a University Campus located in Trieste, Italy. The system operation is based on a cost-optimal control strategy and the effect of the size of the cogeneration unit and heat pumps was investigated. A comparison with a conventional configuration, without distributed heat pumps, was also performed. The results show that the proposed configuration outperformed the conventional one, leading to a total-cost saving of around 8%, a carbon emission reduction of 11%, and a primary energy saving of 8%.

scholarly journals Study on the Certification Policy of Zero-Energy Buildings in Korea

2020 ◽  
Vol 12 (12) ◽  
pp. 5172 ◽  
Author(s):  
Yeweon Kim ◽  
Ki-Hyung Yu
Keyword(s):  
Energy Efficiency ◽  
Renewable Energy ◽  
Energy Consumption ◽  
Residential Buildings ◽  
Building Energy ◽  
Primary Energy ◽  
Zero Energy ◽  
Renewable Energy Consumption ◽  
Self Sufficiency ◽  
Zero Energy Buildings

This study presents a methodology and process to establish a mandatory policy of zero-energy buildings (ZEBs) in Korea. To determine the mandatory level to acquire the rating of a ZEB in Korea, this study was conducted under the assumption that the criteria of ZEB was a top 5% building considering the building’s energy-efficiency rating, which was certified through a quantitative building energy analysis. A self-sufficiency rate was also proposed to strengthen the passive standard of the buildings as well as to encourage new and renewable energy production. Accordingly, zero-energy buildings (ZEBs) in Korea are defined as having 60 kWh/(m2·yr) of non-renewable primary energy (NRPE) consumption in residential buildings and 80 kWh/(m2·yr) in non-residential buildings, and the self-reliance rate should be more than 20% of the renewable energy consumption as compared to the total energy consumption of the buildings. In addition, the mandatory installation of building energy management systems (BEMS) was promoted to investigate the energy behavior in buildings to be certified as zero-energy in the future. This study also investigated the number of ZEB certificates during the demonstration period from 2017 to 2019 to analyze the energy demand, non-renewable primary energy, renewable primary energy, and self-sufficiency rate as compared to those under the previous standards. For ZEB Grade 1 as compared to the existing building energy-efficiency rating, the sum of the NRPE decreased more than 50%, and renewable energy consumption increased more than four times.

scholarly journals ENERGIJOS ŠALTINIŲ PARINKIMO ĮTAKA PASTATO ENERGINIAM NAUDINGUMUI / IMPACT OF ENERGY SOURCES SELECTION FOR ENERGY PERFOMANCE OF BUILDING

2018 ◽  
Vol 10 (0) ◽  
pp. 1-6
Author(s):  
Rūta Mikučionienė ◽  
Vygantas Žėkas
Keyword(s):  
Energy Production ◽  
Alternative Energy ◽  
Production Systems ◽  
Building Energy ◽  
Energy Performance ◽  
Heat Pumps ◽  
Solar Photovoltaic ◽  
Energy Demands ◽  
Zero Energy Building ◽  
Selection For

The article analyzes energy supply alternatives for administrative nearly zero energy building in Kaunas. Alternative energy production systems such as biofuel boiler, condensing boiler, heat pumps (air-water and groundwater), solar photovoltaic, solar collectors and combinations of these systems are analysed. The simulation of analysed building energy demands has been made using DesignBuilder modelling software and modelling of energy production alternatives has been performed using energyPRO software. In order to determine the optimal energy production alternative, the combinations of technologies are compared by energetic and ecological indicators and influence of each combination on the energy performance class is assessed. Santrauka Vis griežtėjantys Europos Sąjungos reikalavimai pastatų sektoriuje reikalauja efektyvesnių ir ekologiškesnių sprendimų aprūpinant pastatus energija, todėl būtina ieškoti geriausių aprūpinimo energija variantų juos įvertinant keliais kriterijais. Tiriamos administracinio beveik nulinės energijos pastato šios aprūpinimo energija technologijos: biokuro katilas, kondensacinis dujų katilas, šilumos siurbliai (gruntas–vanduo ir oras–vanduo), šalčio mašina, centralizuoti šilumos tinklai, saulės elementai ir saulės kolektoriai. Pastato poreikiai modeliuojami DesignBuilder, o aprūpinimo energija technologijų deriniai modeliuojami energyPRO modeliavimo programa. Siekiant nustatyti optimalų aprūpinimo energija variantą, technologijų deriniai yra lyginami pagal energinį ir ekologinį rodiklius ir įvertinama kiekvieno derinio įtaka pastato energinio naudingumo klasei.

scholarly journals Environmental aspects of energy supply of buildings in Poland

2018 ◽  
Vol 49 ◽  
pp. 00097 ◽  
Author(s):  
Robert Sekret
Keyword(s):  
Energy Source ◽  
Renewable Energy ◽  
Environmental Impact ◽  
Energy Supply ◽  
Heat Supply ◽  
Building Energy ◽  
Heat Pumps ◽  
Heat Distribution ◽  
Building Heat ◽  
Supply Systems

The article presents the assessment of the environmental impact of 9 variants of building heat supply for heating purposes. The building energy standards and the main primary energy carriers being in use in Poland were taken as input data. The subject of analysis was a single-family house characterized by a utility energy demand of 47 kWh/(m2 year). An environmental impact analysis was made using the specification for LCA in damage categories encompassing human health, ecosystem quality and natural resources depletion. From the obtained results it has been found that coal-based technologies in Poland's building energy supply systems are capable of reducing the noxious environmental impact. An example of such a system is the effective heat distribution network with a coal-based cogeneration energy source. From the point of view of radical low emission reduction, an interesting solution is the effective heat distribution network with a gas-based cogeneration energy source. Nevertheless, forecasts about the development of renewable energy source installations in Poland indicate that a significant role in building heat supply systems will be played by solar systems and geothermal systems using heat pumps. Achieving the environmental acceptance of heat pumps in Poland's conditions requires a decisive intensification of efforts to increase the share of renewable energy sources in electric energy generation processes in the central electric power system and in local and individual systems, as well as the continuation of the processes of thermal insulation of already existing buildings.

scholarly journals Energy, environmental and economic analysis of electric vapour compression and gas driven absorption heat pumps for single-family houses

2021 ◽  
Vol 312 ◽  
pp. 06001
Author(s):  
Giorgio Villa ◽  
Rossano Scoccia ◽  
Tommaso Toppi ◽  
Marcello Aprile
Keyword(s):  
Energy Savings ◽  
Primary Energy ◽  
Heat Pumps ◽  
Hot Water ◽  
Single Family ◽  
Time Step ◽  
Dynamic Simulations ◽  
Emission System ◽  
Operative Costs ◽  
Vapour Compression

The aim of this paper is to compare energy consumptions, CO2 emissions, and operative costs of condensing boilers, electric vapour compression heat pumps and gas driven absorption heat pumps to provide space heating and domestic hot water. The analysis is performed for 140 m2 single-family houses in five different Italian cities whose envelope features depend on the location. For each location, two different envelope conditions are considered. The first one is a non-insulated building, while the second one is the same building, but an external thermal insulation is added on vertical walls and roof. To avoid internal renovation, radiators are maintained as emission system. Combined dynamic simulations are performed to appreciate building and system interactions. A 6 second time step is set to evaluate properly interactions and the DHW profile demand. In addition, the GHP dynamic model is a grey box model experimentally validated. The results show that electric vapour compression heat pumps reach the highest non-renewable primary energy savings (>32%) compared to condensing boilers, but their operative costs are higher due to the higher specific cost of electricity in Italy. Gas driven absorption heat pumps achieve a lower consumption reduction than electric heat pumps (>22%), but they have also the minimum operative cost among the three technologies.

On Energy Status indicators and the role of renewableEnergy under Economic Crisis

2014 ◽  
pp. 92-105
Author(s):  
P. Bezrukikh ◽  
P. Bezrukikh (Jr.)
Keyword(s):  
Renewable Energy ◽  
World Economy ◽  
Electrical Energy ◽  
Primary Energy ◽  
Primary Energy Consumption ◽  
Energy Status ◽  
Economy Growth ◽  
The World ◽  
Production Regime

The article analyzes the dynamics of consumption of primary energy and production of electrical energy in the world for 1973-2012 and the volume of renewable energy. It is shown that in the crisis year of 20 0 9 there was a significant reduction in primary energy consumption and production of electrical energy. At the same time, renewable energy has developed rapidly, well above the rate of the world economy growth. The development of renewable energy is one of the most effective ways out of the crisis, taking into account its production regime, energy, environmental, social and economic efficiency. The forecast for the development of renewable energy for the period up to 2020, compiled by the IEA, is analyzed. It is shown that its assessment rates are conservative; the authors justify higher rates of development of renewable energy.

Saving Primary Energy Consumption Through Exergy Analysis of Combine Distillation and Power Plant

2012 ◽  
Vol 9 (2) ◽  
pp. 65
Author(s):  
Alhassan Salami Tijani ◽  
Nazri Mohammed ◽  
Werner Witt
Keyword(s):  
Energy Consumption ◽  
Power Plant ◽  
Heat Pump ◽  
Heat Recovery ◽  
Energy Savings ◽  
Primary Energy ◽  
Heat Pumps ◽  
Saturated Steam ◽  
Distillation Unit ◽  
Primary Energy Consumption

Industrial heat pumps are heat-recovery systems that allow the temperature ofwaste-heat stream to be increased to a higher, more efficient temperature. Consequently, heat pumps can improve energy efficiency in industrial processes as well as energy savings when conventional passive-heat recovery is not possible. In this paper, possible ways of saving energy in the chemical industry are considered, the objective is to reduce the primary energy (such as coal) consumption of power plant. Particularly the thermodynamic analyses ofintegrating backpressure turbine ofa power plant with distillation units have been considered. Some practical examples such as conventional distillation unit and heat pump are used as a means of reducing primary energy consumption with tangible indications of energy savings. The heat pump distillation is operated via electrical power from the power plant. The exergy efficiency ofthe primary fuel is calculated for different operating range ofthe heat pump distillation. This is then compared with a conventional distillation unit that depends on saturated steam from a power plant as the source of energy. The results obtained show that heat pump distillation is an economic way to save energy if the temperaturedifference between the overhead and the bottom is small. Based on the result, the energy saved by the application of a heat pump distillation is improved compared to conventional distillation unit.

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