scholarly journals The Impact of Load Profile on the Grid-Interaction of Building Integrated Photovoltaic (BIPV) Systems in Low-Energy Dwellings

2010 ◽  
Vol 5 (4) ◽  
pp. 137-147 ◽  
Author(s):  
R Baetens ◽  
R De Coninck ◽  
L Helsen ◽  
D Saelens

A building integrated photovoltaic system (BIPV) system may produce the same amount of electricity as consumed in the building on a yearly base. The simultaneity of production and consumption however needs to be evaluated: the distribution grid is regarded as virtual storage and is loaded unconventionally or even overloaded. A detailed bottom-up modelling approach of the domestic load, thermal installations and the local generation of BIPV system may give more insight. The present paper aims at quantifying the impact of domestic load profiles on the grid-interaction of BIPV-equipped dwelling in a moderate Belgian climate wherefore the cover factor is defined. For a yearly electricity production that equals the yearly domestic demand, a cover factor of 0.42 is found if a classic heating system is installed, denoting that more than half of the produced electricity will be passed on to the grid and withdrawn on another moment. If a heat pump is used for space heating and domestic hot water, the cover factor decreases to 0.29.

2014 ◽  
Vol 541-542 ◽  
pp. 942-948
Author(s):  
Xian Peng Sun ◽  
Zhi Rong Zou ◽  
Yue Zhang

Based on the finite-time thermodynamic theory, an operation optimization, of water source heat pump in the combined solar with a dual heat source heat pump which is applied in a greenhouse heating system, is made. According to the ε-NTU method and entropy theory, heat exchange and balance equations are obtained. The function relationship between COP and the indoor temperature Tn, the ambient temperature Ta, low temperature heat source inlet temperature Tie and high temperature heat source inlet temperature Tic is also obtained. By means of programming, the impact of parameters on the COP and the way of regulating this water source heat pump system are presented in this article. The results show that: when a separate water source heat pump is running, by adjusting the hot water temperature and the match status of each indoor heating system, the energy-saving operation can be realized.


Author(s):  
William J. Stein ◽  
Roch A. Ducey ◽  
Bruce R. Johnson

Fort Huachuca, AZ, located 60 mi Southeast of Tucson, has had over 30 years of experience with various renewable energy systems. This session discusses lessons learned from the successes and failures in that experience, including: an indoor pool solar water heating system (installed 1980); a solar domestic hot water (DHW) system (installed 1981); a grid connected Photovoltaic system (installed 1982); transpired air solar collectors (Solarwalls,™ installed 2001); day-lighting (installed 2001); a 10-KW wind turbine (installed 2002); photovoltaic powered outdoor lighting (installed 1994); a prototype Dish/Stirling solar thermal electric generator (installed 1996); two 30-KW Building Integrated Photovoltaic systems (installed on new membrane roofs in 2009); and a 36-KW Photovoltaic system moved from the Pentagon in June 2009 and became operational November 2009 at Fort Huachuca. Also discussed is an experimental solar attic system (first installed in 2003 and now being fully monitored) that collects hot air in an attic, and via a heat exchanger and tank, produces solar DHW. This paper discusses system design, installation, metering, operation and maintenance, and also work in progress on the installation of commercial, off-the-shelf 3-KW Dish/Stirling solar thermal electric generators and solar thermal/natural gas-to-electric systems at a central plant. Discussions include biogas (methane from a wastewater digester) and biomass (wood chip boiler) being installed at a central heating/cooling plant.


Energies ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 5476
Author(s):  
Sławomir Zator ◽  
Waldemar Skomudek

This article presents a case study of a single-family house, whose current energy source is electricity only. Nine years ago, the heat source for the heating system and domestic hot water was an oil boiler, which was changed to an air–water heat pump. Four years ago, when Poland formed the basis of the prosumer market, the first photovoltaic system was established. It was expanded in the following years. In this work are presented the impact of using a heat accumulator on the coefficient of performance of the heat pump, the self-consumption of energy from the photovoltaic system, and the cost of purchasing energy. Comparative calculations were made, with the demand-side management (DSM) active on work days, and on free days (weekends and public holidays) it was not. Attention was paid to the self-consumption factor depending on the algorithms used in an energy meter. The prosumer market in Poland was also described. The calculations described the house as having an annual energy self-consumption from photovoltaic about 6% higher than average values obtained in buildings with heat pumps. Simultaneously, due to energy storage in heat and the load shifting in the multi-zone tariff, the cost of purchasing energy was 47% lower than in a single-zone tariff (without heat storage and load shifting).


Energies ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4694
Author(s):  
Tina Lidberg ◽  
Thomas Olofsson ◽  
Louise Ödlund

When buildings become more energy effective, the temperature levels of district heating systems need to be lower to decrease the losses from the distribution system and to keep district heating a competitive alternative on the heating market. For this reason, buildings that are refurbished need to be adapted to suit low-temperature district heating. The aim of this paper is to examine whether four different energy refurbishment packages (ERPs) can be used for lowering the temperature need of a multi-family buildings space heating and domestic hot water (DHW) system as well as to analyse the impact of the DHW circulation system on the return temperature. The results show that for all ERPs examined in this study, the space heating supply temperature agreed well with the temperature levels of a low-temperature district heating system. The results show that the temperature need of the DHW system will determine the supply temperature of the district heating system. In addition, the amount of days with heating demand decreases for all ERPs, which further increases the influence of the DHW system on the district heating system. In conclusion, the DHW system needs to be improved to enable the temperature levels of a low-temperature district heating system.


Author(s):  
Mehmet Bulut

With the year 2020, the world faced a new threat that affects all areas of life, negatively affects production in all areas, and paralyzes social life. The measures and restrictions taken by the country's governments to prevent the epidemic from spreading rapidly in the society with the effect of the Covid-19 virus, which first appeared in China and spread all over the world, brought a new lifestyle. Covid-19 has been much the impact on electricity use and electricity production in the period in Turkey as in other countries. There was a sharp decline in commercial and industrial electricity use. The coronavirus effect has also been reflected in the electricity demand and the consumption amount has undergone a great negative change. Due to the enactment of measures against the new type of coronavirus (COVID-19) epidemic and the partial or full-time curfews, electricity consumption was moved to homes, supermarkets, and hospitals in April 2020 from places where mass consumption is intense, such as industry, workplaces, and educational institutions. In this study, Covid-19 period, the first cases were examined electricity production and consumption in Turkey as of the date it is seen throughout, in comparison with electricity consumption data in the same month of the previous years corresponding to this period, the effects on electricity generation and consumption habits of this period were examined.


2020 ◽  
Vol 12 (24) ◽  
pp. 10521
Author(s):  
Mariusz Szreder ◽  
Marek Miara

A standard Polish household with a central heating system powered by a solid fuel furnace was chosen as a case study. The modular Air Source Heat Pump (ASHP) was used to heat the hot water outside the heating season. In this article comparative studies of the impact of the compressor drive system used on the energy efficiency of the heat pump have been carried out in operating conditions. The ASHP heating capacity and coefficient of performance (COP) were determined for the outside air temperature in the range from 7 to 22 °C by heating the water in the tank to a temperature above 50 °C. For the case of a fixed speed compressor, average heating capacity in the range 2.7−3.1 kW and COP values in the range 3.2−4.6 depending on the evaporator supply air temperature were obtained. Similarly, for the inverter compressor, the average heating capacity in the range of 2.7−5.1 kW was obtained for the frequency in the range of 30–90 Hz and COP in the range 4.2−5.7, respectively. On cool days, the average heating capacity of the heat pump decreases by 12%. For the simultaneous operation of two compressors with comparable heating capacity, lower COP values were obtained by 20%.


Author(s):  
Erkki JÕGI ◽  
Alo ALLIK ◽  
Hardi HÕIMOJA ◽  
Tõnis PEETS ◽  
Heino PIHLAP ◽  
...  

The current paper addresses energy storage issues in residential buildings with the objective of increasing direct consumption. The building, connected to an utility grid, is supplied by a micro wind turbine and PV panels. The utility grid itself acts as an energy buffer. Only nonshiftable loads (white goods, TV etc.) and electric water heating are taken into account. The studied configuration comprises two cascaded heating boilers, one of them preheating boiler. The annual electricity production of the micro wind turbine and PV panels is chosen to cover the hot water demand and nonshiftable loads inside the building with 70/30 ratio in favour of the wind energy. During the experiments, the generation graphs’ shaving levels vary between 0 and 100 %, with peak energy diverted into a preheating boiler and the remaining part fed into the main boiler. The proposed solution allows increasing locally consumed energy share, as the energy of stochastic peaks is stored and used on later demand. The locally consumed energy is expressed by the cover factor, its increase possibilities are studied in main text. Calculations are based on 5- minute time series. The applied algorithm follows the amount of heat in the main and preheating boiler, including also incoming and outgoing energies. The cover factor cannot be increased without restrictions. Too high shaving levels bring along problem of removing excess heat from the preheating boiler. The allowed drain loss is taken as 10 % of annual boiler energy balance. The presumed growth of the cover factor at preheating boiler volume of 160 l instead of 80 l is at least 8 %. with the main boiler sized as before.


2013 ◽  
Vol 2013 ◽  
pp. 1-6
Author(s):  
Utpal Gangopadhyay ◽  
Sukhendu Jana ◽  
Sayan Das ◽  
Sutapa Garain ◽  
Soma Ray

Building-integrated photovoltaic (BIPV) systems represent an interesting, alternative approach for increasing the available area for electricity production and potentially for further reducing the cost of solar electricity. In BIPV systems, the visual impression of a solar module becomes important, including its color. However, the range of solar cell colours and shapes currently on offer to architects and BIPV system designers is still very limited, and this is a barrier to the widespread use of PV modules as a constructional “material.” The color of a solar module is determined by the color of the cells in the module, which is given by the antireflection coating (ARC). However, access to efficient, but differently colored, solar cells is important for the further development of BIPV systems. In this paper, we have used Diamond-like nanocomposite layer as an Antireflective Nanocomposite based (ARNAB) coating material for crystalline silicon solar cell, and the impact of varying the color of an ARC upon the optical characteristics and efficiency of a solar cell is investigated. In addition to a comparison of the optical characteristics of such solar cells, the effect of using colored ARCs on solar cell efficiency is quantified using the solar cell modeling tool PC1D.


Energies ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1678 ◽  
Author(s):  
Sonja Salo ◽  
Aira Hast ◽  
Juha Jokisalo ◽  
Risto Kosonen ◽  
Sanna Syri ◽  
...  

Demand response has been studied in district heating connected buildings since the rollout of smart, communicating devices has made it cost-effective to control buildings’ energy consumption externally. This research investigates optimal demand response control strategies from the district heating operator perspective. Based on earlier simulations on the building level, different case algorithms were simulated on a typical district heating system. The results show that even in the best case, heat production costs can be decreased by only 0.7%. However, by implementing hot water thermal storage in the system, demand response can become more profitable, resulting in 1.4% cost savings. It is concluded that the hot water storage tank can balance district heating peak loads for longer periods of time, which enhances the ability to use demand response strategies on a larger share of the building stock.


Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 90
Author(s):  
Miroslaw Zukowski

In this article, the research object is the solar domestic hot water (SDHW) heating system that has been in operation since 2015 and is located on the campus of the Bialystok University of Technology (Poland). The thermal performance of solar collectors are thoroughly investigated so far. Therefore, special attention was paid to the issue of the heat loss from pipes. The measurements showed that the heat transfer in circulation pipes is quite complex due to continuous fluctuations in water temperature at the supply of this loop. As it turned out, the application of the classical method of energy balancing and the readings from heat meters gave inaccurate results in this case. The main aim of this study was to develop a different approach to solving the problem of determination of heat losses. The method presented in this article is based on computational fluid dynamics (CFD) and measurement results as the input data. The practical result of this study was the development of two relationships for calculating the heat loss from pipes. A separate issue, that is discussed in this paper, concerns the impact of the time intervals used in numerical simulations on the accuracy of calculation results.


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