scholarly journals Analysis of thermal and electrical efficiency of photovoltaic/thermal – PV/T modules operating in moderate climate at microscale

2018 ◽  
Vol 70 ◽  
pp. 01002
Author(s):  
Dorota Chwieduk ◽  
Jarosław Bigorajski
Keyword(s):  
Thermal Energy ◽  
Electrical Energy ◽  
Hot Water ◽  
Electricity Production ◽  
Energy Output ◽  
Single Family ◽  
System Operation ◽  
Electrical Efficiency ◽  
The Difference ◽  
T System

The paper presents an application concept for PV/T - Photovoltaic Thermal Technology in moderate climates (such as the Polish climate), at a micro scale, i.e. for a single family house. The paper analyses the operation of a PV/T system applied to Domestic Hot Water – DHW heating and electricity production. A mathematical model of the system operation has been developed. The paper focuses on modeling thermal and electrical efficiency of photovoltaic/thermal - PV/T modules. It also briefly presents the governing equations for the thermal energy balance of a storage tank, where thermal stratification effects take place. Some selected results of the numerical simulation of the PV/T system operation are described. Daily distribution of hourly averaged thermal and electrical efficiency of the PV/T modules without cover and with one glazing are presented. The PV/T systems do not give significant thermal energy output in winter. PV/T modules without glazing do not supply heat at all for three winter months, their highest thermal efficiency is in summer and it can be nearly 15%. In the same period glazed modules have efficiency equal to nearly 24%. However, the unglazed modules can give much more electrical energy in summer than those with glazing, and the electrical efficiency can reach the levels of 11.4% and 9.4%, respectively. In winter the difference is smaller, i.e. for unglazed the efficiency is 12.2%, and for glazed 11.2%.

scholarly journals Evaluation of the coefficient of performance of an air source heat pump unit and an air to water heat pump

2021 ◽  
Vol 32 (1) ◽  
pp. 27-40
Author(s):  
S. Tangwe ◽  
K. Kusakana
Keyword(s):  
Heat Pump ◽  
Thermal Energy ◽  
Pressure Sensors ◽  
Electrical Energy ◽  
Hot Water ◽  
Coefficient Of Performance ◽  
Water Heaters ◽  
Air Source Heat Pump ◽  
Heat Pump Unit ◽  
The Difference

Air source heat pump (ASHP) water heaters are efficient devices for sanitary hot water heating. The coefficient of performance (COP) of the air to water heat pump (AWHP) is constantly lower than that of the corresponding ASHP unit. The study focused on determining the COP of both the ASHP unit and the AWHP. This was achieved by the implementation of both experimental and simulation methods, with the help of a data acquisition system and the REFPROP software. The system comprised of a 1.2 kW split type ASHP unit and a 150 L high pressure geyser. A power meter, flow meters, temperature sensors, pressure sensors, ambient temperature and relative humidity sensor were installed at precise locations on the split type AWHP. Controlled volumes of 150, 50 and 100 L were drawn off from the AWHP during the morning, afternoon and evening for a year. The average COP for the summer and winter, in terms of the input electrical and output thermal energies of the AWHP were 3.02 and 2.30. The COPs of the ASHP unit, in terms of the change in the enthalpies of the refrigerant at the inlet and the outlet of the condenser and the evaporator, were 3.52 and 2.65 respectively. The study showed that the difference between the COP of the ASHP unit and that of the AWHP could be ascribed to the electrical energy consumed by the fan and the water circulation pump during the vapour compression refrigeration cycles. The work provides an energy optimisation opportunity to the manufacturers of this technology, helping to enhance the efficiency and COP of ASHP water heaters. Highlights The COPt of the ASHP unit was higher than the COPe of the AWHP. The COPe of the AWHP was the ratio of the input electrical energy consumed and the output thermal energy gained by the stored water. The COPt of the ASHP unit was enthalpies-dependent and a function of inlet and outlet enthalpies of the evaporator and condenser. The inlet and outlet refrigerant temperatures profiles of the condenser confirmed thermal energy dissipation.

scholarly journals Air Density Climate of Two Caribbean Tropical Islands and Relevance to Wind Power

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Xsitaaz Twinkle Chadee ◽  
Ricardo Marcus Clarke
Keyword(s):  
Wind Turbine ◽  
Electrical Energy ◽  
Dew Point ◽  
Energy Output ◽  
Small Island ◽  
Air Density ◽  
Wind Turbine System ◽  
Island State ◽  
The Difference ◽  
Small Island State

The standard air density of 1.225 kg m−3 is often used in determining the energy output of a wind turbine although the energy output is dependent on a site's air density. By using measurements of temperature, dew-point temperature, and pressure, we calculate the monthly air density of moist tropical climates at two sites in the small-island state of Trinidad and Tobago. In addition, we calculate the energy output of a BOREAS 30 kW small wind turbine using the 10 m level wind speed distribution extrapolated to hub height. The average air densities at Crown Point and Piarco were 1.156 kg m−3 and 1.159 kg m−3, respectively, and monthly air densities at both sites were at most 6% less than standard air density. The difference in energy output of the BOREAS 30 kW calculated using standard air density over that using the local site's air density could provide electrical energy for the continuous monthly operation of 6 light bulbs rated at 50 W at Crown Point and 4 light bulbs at Piarco. Thus, communities interested in implementing wind turbine technologies must use the local air density of the site when sizing a wind turbine system for its needs.

A review on the application of photovoltaic thermal systems for building façades

2019 ◽  
Vol 41 (1) ◽  
pp. 86-107 ◽  
Author(s):  
Ahmad Riaz ◽  
Ruobing Liang ◽  
Chao Zhou ◽  
Jili Zhang
Keyword(s):  
Thermal Energy ◽  
Large Scale ◽  
Electrical Energy ◽  
Building Envelope ◽  
Hot Water ◽  
Working Fluid ◽  
Thermal Systems ◽  
Air Supply ◽  
Building Facades ◽  
Photovoltaic Thermal System

The hybrid photovoltaic-thermal system has shown great progress. Electrical energy is produced from PV panels while thermal energy is produced via a working fluid carried through the panels. In this paper, the vertical PV/T is introduced using working fluids such as air and liquid, which serve to control the excess temperature of the PV panels as well as to collect heat to be made available as thermal energy. Installations of PV/T systems on building façades, as well as integration with other technologies such as heat pipe and heat pump are also discussed. Current studies of such building integration technologies are also explored, including the scale of application. This study aims to provide constructive information which can be used in future development of building facades for large-scale applications, to contribute to future sustainable development. Practical application: This study helps researchers and engineers who are considering photovoltaic thermal systems for building façades to have better understanding of its effect on electrical and thermal energy – for space heating, fresh air supply and hot water supply – using an active building envelope.

scholarly journals Analisa Pembangkit Listrik Tenaga Diesel Gas Dengan Menggunakan Bahan Bakar LNG Dan Minyak Solar Di PT Indonesia Power Unit Pembangkitan Bali

Jurnal METTEK ◽  
2018 ◽  
Vol 4 (1) ◽  
pp. 31
Author(s):  
K G Trisna Upadana Putra ◽  
I Gusti Bagus Wijaya Kusuma ◽  
Made Sucipta
Keyword(s):  
Diesel Fuel ◽  
Electric Energy ◽  
Production Capacity ◽  
Engine Performance ◽  
Electrical Energy ◽  
Plant Performance ◽  
Electricity Production ◽  
High Demand ◽  
The Difference ◽  
Performance Equation

Permintaan energi listrik mengalami peningkatan, seiring peningkatan pertumbuhan populasi penduduk dan banyaknya industri. Tingginya permintaan energi listrik menjadi sebuah tantangan untuk produsen listrik, dalam memenuhi kebutuhan pelanggan akan energi listrik. Produsen listrik terbesar di Bali adalah PT. Indonesia Power UP Bali. Pembangkit yang dimiliki yaitu PLTDG dengan kapasitas produksi listrik 200 MW dioperasikan menggunakan bahan bakar gas LNG dan minyak solar (HSD/LFO). Dikarenakan penggunaan minyak solar dibatasi, maka PLTDG dioperasikan dengan gas LNG. Perbedaan bahan bakar yang digunakan mempengaruhi unjuk kerja dari pembangkit. Analisa unjuk kerja memberi gambaran dalam sisi keteknikan dan analisa BPP pembangkitan memberi gambaran dalam sisi keekonomian. Penelitaian ini dilakukan dengan cara perhitungan menggunakan persamaan-persamaan unjuk kerja mesin diesel, kemudian dibandingkan unjuk kerja PLTDG menggunakan bahan bakar LNG dan minyak solar dan dianalisa secara keekonomian. Hasil yang didapat yaitu unjuk kerja PLTDG menggunakan minyak solar lebih besar tetapi dari sisi keekonomian hasil BPP PLTDG menggunakan gas LNG lebih ekonomis. Demand for electric energy has increased, as population growth increases and the number of industries. The high demand for electrical energy becomes a challenge for electricity producers, in meeting the needs of customers for electrical energy. The largest power producer in Bali is PT. Indonesia Power UP Bali. The power plant owned by PLTDG with 200 MW electricity production capacity is operated using LNG gas and diesel fuel (HSD/LFO). Due to the use of diesel fuel is limited, the PLTDG is operated with LNG gas. The difference in fuel used affects the performance of the plant. Performance analysis gives an overview in terms of engineering and BPP analysis provides an overview of the economy side. This research is done by calculation using diesel engine performance equation, and then compared the performance of PLTDG using LNG and diesel fuel and analyzed economically. The results obtained are the performance of diesel powered PLTDG larger but in terms of economics of BPP PLTDG results using LNG gas is more economical.

scholarly journals Glazed Photovoltaic-thermal (PVT) Collectors for Domestic Hot Water Preparation in Multifamily Building

2020 ◽  
Vol 12 (15) ◽  
pp. 6071
Author(s):  
Nikola Pokorny ◽  
Tomáš Matuška
Keyword(s):  
Thermal Energy ◽  
Simulation Study ◽  
Water System ◽  
Hot Water ◽  
Electrical Performance ◽  
Electricity Production ◽  
Thermal System ◽  
Conventional System ◽  
Domestic Hot Water ◽  
Photovoltaic Thermal System

Photovoltaic–thermal collector generates electrical and thermal energy simultaneously from the same area. In this paper performance analysis of a potentially very promising application of a glazed photovoltaic–thermal collector for domestic hot water preparation in multifamily building is presented. Solar system in multifamily building can be installed on the roof or integrated in the façade of the building. The aim of this simulation study is to show difference of thermal and electrical performance between façade and roof installation of a glazed photovoltaic-thermal collectors at three European locations. Subsequently, this study shows benefit of photovoltaic-thermal collector installation in comparison with side-by-side installation of conventional system. For the purpose of simulation study, mathematical model of glazed photovoltaic-thermal collector has been experimentally validated and implemented into TRNSYS. A solar domestic hot water system with photovoltaic–thermal collectors generates more electrical and thermal energy in comparison with a conventional system across the whole of Europe for a particular installation in a multifamily building. The specific thermal yield of the photovoltaic–thermal system ranges between 352 and 582 kWh/m2. The photovoltaic–thermal system electric yield ranges between 63 and 149 kWh/m2. The increase in electricity production by the photovoltaic–thermal system varies from 19% to 32% in comparison with a conventional side-by-side system. The increase in thermal yield differs between the façade and roof alternatives. Photovoltaic-thermal system installation on the roof has higher thermal yield than conventional system and the increase of thermal yield ranges from 37% to 53%. The increase in thermal yield of façade photovoltaic-thermal system is significantly higher in comparison with a conventional system and ranges from 71% to 81%.

Performance Evaluation of an Asymmetric Hybrid Solar Collector: Effect of Nanofluids on the Electrical and Thermal Energy Production

2016 ◽  
Author(s):  
M. T. Nitsas ◽  
I. P. Koronaki ◽  
A. S. Kontos
Keyword(s):  
Performance Evaluation ◽  
Thermal Energy ◽  
Solar Collector ◽  
Energy Production ◽  
Calculated Data ◽  
Electrical Energy ◽  
Hot Water ◽  
Cell Efficiency ◽  
Asymmetric Hybrid ◽  
The Mediterranean

The scope of this work is the analysis of the electrical and thermal performance of an asymmetric hybrid solar collector PVT and the prospect of the installation of a system consisting of these collectors in the Mediterranean region. For the purpose of this work, the Solarus V11 PVT collector (readily available in our laboratory) was chosen and numerically modeled. The main asset of this collector is its asymmetric reflector that consists of a circular and a parabolic part leading to a maximum thermal energy production even in winter as the solar radiation is concentrated in the edge of the reflector rather than in the center of it. Using a software developed in Matlab, the calculated data are presented for both thermal and electrical energy and they are compared with the hot water and electrical energy requirements (per month) around the Mediterranean territory. Furthermore, a parametric study is conducted in order to investigate the effect of the mass flow rate and the PVT array configuration on the thermal and electrical production, as well as the efficiency of the solar cells of the system. Moreover, in order to increase the PV cell efficiency, nanofluids, i.e. mixtures of nanometer size particles well-dispersed in a base fluid, are proposed as heat transfer fluids and the analysis for the performance evaluation is conducted for different nanoparticle loadings.

scholarly journals Improving performance of direct expansion air conditioning systems while reducing electricity consumption through using hybrid energy

2021 ◽  
Vol 289 ◽  
pp. 01014
Author(s):  
Ahmed Al–Okbi ◽  
Yuri Vankov ◽  
Hakim Kadhim
Keyword(s):  
Energy Consumption ◽  
Thermal Energy ◽  
Air Conditioning ◽  
Electrical Energy ◽  
Coefficient Of Performance ◽  
Electricity Production ◽  
Conventional System ◽  
Solar Thermal Energy ◽  
Continuous Power ◽  
Air Conditioning Systems

At the present time, operating hybrid air-conditioning systems that use solar energy to saving electrical energy while improving the performance has become necessary to protect the environment, reduce pollution and emissions caused by using fuels and gases. In Iraq, temperatures reach half the boiling point at summer, therefore the demand for air conditioning systems increases, air conditioning systems consume more than half of average electricity production which affects on reliability and stability of the electrical energy thus leads to a continuous power outage. So, the issue of using renewable energies becomes more attractive. Because of saving energy leads to ensuring the reliability of electricity and reduces the consumption of fuels and gases that pollute on the environment and negatively affect on the ozone layer. In the current research, the atmosphere of Baghdad city was used to collect solar thermal energy and convert it into thermal energy through an evacuated solar collector by water and combine it with a conventional air conditioner in the part that follows the compressor in order to reduce the electrical energy consumption on the compressor and increase coefficient of performance. Several tests were conducted on the proposed system to compare results with the conventional system and evaluate performance. The results showed that the coefficient of performance with the hybrid system became 8.97 more efficient instead of 4.27 compared to the conventional system, and the energy consumption decreased by 52%.

Experimental investigation of the novel BIPV/T system employing micro-channel flat-plate heat pipes

2018 ◽  
Vol 39 (5) ◽  
pp. 540-556 ◽  
Author(s):  
Zhangyuan Wang ◽  
Zicong Huang ◽  
Fucheng Chen ◽  
Xudong Zhao ◽  
Peng Guo
Keyword(s):  
Heat Transfer ◽  
Flat Plate ◽  
Water Flow ◽  
Thermal Energy ◽  
Thermal Efficiency ◽  
Heat Pipes ◽  
Micro Channel ◽  
Plate Heat ◽  
Electrical Efficiency ◽  
T System

In this paper, the micro-channel flat-plate heat pipes-based BIPV/T system has been proposed, which is expected to have the characteristics, e.g. reduced contact thermal resistance, enhanced heat transfer area, improved heat transfer efficiency and building integration. The proposed system was constructed at the laboratory of Guangdong University of Technology (China) to study its performance. The temperatures of the glass cover, PV panel, micro-channel flat-plate heat pipes, and tank water were measured, as well as the ambient temperature. The thermal and electrical efficiency was also calculated for the system operated under the conditions with different simulated radiations and water flow rates. It was found that the proposed system can achieve the maximum average overall efficiency of 50.4% (thermal efficiency of 45.9% and electrical efficiency of 4.5%) for the simulated radiation of 300 W/m2 and water flow rate of 600 L/h. By comparing the proposed system with the two previous systems employing the conventional heat pipes, the thermal efficiency of the proposed system was clearly improved. The research will develop an innovative BIPV/T technology possessing high thermal conduction capability and high thermal efficiency compared with the conventional BIPV/T system, and helps realise the global targets of reducing carbon emission and saving primary energy in buildings. Practical application: This novel BIPV/T employing micro-channel flat-plate heat pipes will be potentially used in buildings to provide amount of electricity and thermal energy. The generated electricity will be used by the residents for electrical devices, and the thermal energy can be used for hot water, even for space heating and cooling.

scholarly journals A Parametric Study of a Hybrid Photovoltaic Thermal (PVT) System Coupled with a Domestic Hot Water (DHW) Storage Tank

Energies ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 6481
Author(s):  
Madalina Barbu ◽  
George Darie ◽  
Monica Siroux
Keyword(s):  
Storage Tank ◽  
Consumer Demand ◽  
Demand Curve ◽  
Electrical Energy ◽  
Hot Water ◽  
Water Tank ◽  
Domestic Hot Water ◽  
Electrical Efficiency ◽  
Outlet Flow ◽  
The Impact

Photovoltaic-thermal panels are hybrid systems that combine the two types of conventional solar energy technologies (photovoltaic and thermal panels) and simultaneously generate both thermal and electrical energy in a micro-cogeneration system. Like any co-generation system, there is an optimal balance that can be achieved between the thermal and electrical energy produced. For this reason, it is important to establish the relationship and inter-connection between the two. Limited research is available on the cogeneration interaction in a PVT system, so the novelty of this article lies in the consideration of the entire energy system connected to the PVT panel, including the storage tank and the consumer demand curve, and the investigation of the thermal parametric variation. This study analyses the impact of the variation of some thermal parameters of a domestic hot water tank on the electrical efficiency of a photovoltaic-thermal panel. A model of a system of photovoltaic-thermal panels is built in a transient systems simulation program (TRNSYS) and a one-factor-at-a-time analysis is carried out for the cold-water main temperature, tank size, tank outlet flow and consumer demand curve. The results show that the variation of the outlet flow to the consumer has the highest impact on the electrical efficiency, of about 6.8%. The next highest impact factor is the size of the tank with a variation of 4.7%. Matching the profile of the consumer is also an important aspect. It was observed that the peak electrical efficiency occurs during peak consumer demand. Finally, the instantaneous variation of the thermal and electrical power of the system was analysed as a function of the temperature at the inlet of the photovoltaic-thermal panel.

scholarly journals Modelling and Feasibility Study on Using Tidal Power with an Energy Storage Utility for Residential Needs

Inventions ◽  
2019 ◽  
Vol 4 (1) ◽  
pp. 11
Author(s):  
Gianmaria Giannini
Keyword(s):  
Energy Storage ◽  
Thermal Energy ◽  
Energy Demand ◽  
Tidal Energy ◽  
Hot Water ◽  
Energy Output ◽  
Mature Stage ◽  
Tidal Power ◽  
Potential Cost ◽  
Storage Facilities

Tidal power technology is at its mature stage and large deployments are soon expected. The characteristics of tidal energy and its advantage to be predictable make it an ideal type of resource to be coupled with energy storage facilities. Despite this, most energy storage facilities are expensive. The fact that water has a high specific heat capacity makes this a potential cost-effective medium to be used for storing large amounts of thermal energy for balancing renewable energy output. This paper is an investigation on the possible application of integrating hot water reservoirs for storing tidal energy during power output peaks for domestic use. The main objective of this study is to evaluate the major factors incident on the proposed solution and to provide considerations on which real remunerations the proposed idea could bring to communities or to single families. For this purpose, a simplified numerical analysis, concerning three different scenarios, was performed. These scenarios differ by type of buildings and type of thermal energy demand. The study mainly concerns remote communities. Findings indicated that the proposed idea is technically feasible and if applied in the context of residential compounds, this could be more attractive in economic terms.

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