Electrical enhancement period of solar photovoltaic using phase change material
Temperature management in photovoltaic (PV) is critical for the power output. Phase Change Material (PCM) usage enables one to remove heat from the system and achieve enhanced electrical output. This study aims at finding the period of PV electrical enhancement, the increase in power and increase in electrical efficiency achieved using PCM under different working circumstances. Results suggest that as the angle of approach of wind changes from 75° to 0° the electrical enhancement period elevates from 7.0 h to 8.6 h for 5 cm deep PCM box. But, the increase in power drops from 17.6 W/m 2 to 13.6 W/m 2 . As wind speed changes from 6 m/s to 0.2 m/s, the electrical enhancement period drops from 9.1 h to 6.4 h. But, the increase in power rises from 11.8 W/m 2 to 22.8 W/m 2 . The rise in ambient temperature 289 K to 299 K leads to decrement of electrical enhancement period from 12.6 h to 7.1 h. But the increase in power rises from 15.9 W/m 2 to 21.4 W/m 2 . Elevation in temperature for liquification from 291 K to 301 K leads to increment of electrical enhancement period from 6.5 h to 12.3 h.
Novel thermal conductivity enhancing containers for performance enhancement of solar photovoltaics system integrated with phase change material
Phase change material (PCM) has capability to increase the power production of solar photovoltaics (PV) by effective temperature regulation. In this work, Thermal Conductivity Enhancing Containers (TCEC) are proposed. They allow the PCM to extract the heat from all sides of the containers instead of only front which improves the thermal conductivity of the PCM containers and increases the PV electrical efficiency. PCM was filled inside the TCECs and pasted at the back of the PV. Systems with and without PCM, with and without TCEC and systems with different tilt angles have been investigated. The melting of PCM, rate of thermal energy storage, charging efficiency and enhancement in PV performance are analyzed. The behavior of the systems is analyzed for the climates of Portsmouth, UK and Chennai, India. It is seen that the average charging efficiency of PCM can be increased from 49% to 62% using proposed TCEC. Moreover, the average rate of thermal energy storage can be increased from 249 W/m2 of aperture to 302 W/m2 and the PV electrical efficiency can be increased from 17.6% to 19.2% using TCEC-PCM. It is also seen that as the inclination of PCM container decreases from 45° to 0°, the charging efficiency decreases by 32%.
Three dimensional analysis of dye-sensitized, perovskite and monocrystalline silicon solar photovoltaic cells under non uniform solar flux
For low/high concentration, when the distribution of solar radiation is non-uniform over the surface of the solar cell, it gets heated up non-uniformly which affects the cell efficiency. Thus, in the present work, three dimensional analysis of the solar cells is carried out under non-uniform solar flux. It involves partial differential equations. For silicon cells, studies are available that use numerical techniques (involving iterations) to solve the differential equations. However, if the differential equations can be solved analytically, one can get an analytical expression for three dimensional non-uniform temperature distribution of the cell. The current work aims at it. Dye-sensitized (DSSC), perovskite and mono-Si cells are investigated. The effects of wind direction, its speed, inclination and solar irradiance on the three dimensional temperature distribution, heat losses and cell efficiency have been investigated. It is concluded that with increase in wind azimuthal from 0° to 90°, the efficiency decreases from 22.1% to 21.3% for mono-Si, 19.0% to 18.0% for perovskite and 12.0% to 11.9% for DSSC.
Solar photovoltaic panels with finned phase change material heat sinks
Phase change material (PCM) based passive cooling of photovoltaics (PV) can be highly productive due to high latent heat capacity. However, the low rate of heat transfer limits its usefulness. Thus, the presented work aims at the improvement in PV cooling by using finned PCM (FPCM) heat sinks. In the present study, PCM heat sink and FPCM heat sinks were investigated numerically for PV cooling and the extracted heat is used for space heating. 4 kWp PV, PV-PCM and PV-FPCM systems were studied under the weather conditions of Southeast of England. It was observed that the PCM heat sinks can drop the peak PV temperature by 13 K, whereas FPCM heat sinks can enhance the PV cooling by 19 K. The PCM heat sinks can increase the PV electrical efficiency from 13% to 14%. Moreover, the daily electricity generation can be boosted by 7% using PCM and 8% by using FPCM heat sinks. In addition, 7 kWh of thermal output was achieved using the FPCM heat sink, and the overall efficiency of system increased from 13% to 19%.
Optimization of fins fitted phase change material equipped solar photovoltaic under various working circumstances
The present work aims at the optimization of fins fitted phase change material equipped photovoltaic system under different working circumstances for proper power enhancement. Setup has been modelled and the best deepness of fins fitted phase change material enclosure has been computed for a range of daily collective solar flux at photovoltaic panel surface, wind pace, wind azimuth, surroundings temperature, melting point, successive fins distance, fins deepness and fins width in order to analyse the influence of working circumstances. It is shown that the change in wind pace from 0.2 m/s to 6 m/s results in reduction of best deepness of phase change material enclosure from 5.2 cm to 3.7 cm, 5.6 cm to 4.0 cm, 5.8 cm to 4.2 cm, 5.9 cm to 4.3 cm and 5.9 cm to 4.3 cm for successive fins distance of 1 m, 1/2 m, 1/3 m, 1/4 m and 1/5 m respectively for daily collective solar flux at photovoltaic panel as 5000Wh/m2. The change in wind azimuth from 0° to 75° results in increment in the best deepness of enclosure from 3.9 cm to 4.8 cm, 4.3 cm to 5.2 cm, 4.5 cm to 5.4 cm, 4.6 cm to 5.5 cm and 4.6 cm to 5.5 cm for respective fins distances. The power production is increased from 125 W/m2 to 137 W/m2, 140 W/m2, 142 W/m2, 143 W/m2 and 143 W/m2 with fins width of 0 mm, 0.5 mm, 1 mm, 2 mm and 4 mm respectively.