| Work Detail |
Solar modules from Trina Solar, Canadian Solar and Felicity Solar were tested in a prototype photovoltaic-thermal collector that uses excess heat from photovoltaic elements to heat water.
Researchers at Dschang University in Cameroon have tested solar modules from three Chinese manufacturers -Trina Solar, Canadian Solar and Felicity Solar- on photovoltaic-thermal water collectors.
In the proposed system configuration, the heat produced by the photovoltaic panel is recovered through a thermally isolated helical coil heat exchanger and used to heat the water. A south-facing system with a six-degree tilt angle was built using monocrystalline solar modules from Canadian Solar (305W), Trinasolar (305W), and Felicity Solar (250W).
The installation also uses a solenoid valve to allow water recirculation when the temperature below the photovoltaic module rises considerably. "The temperature under the modules and the system is managed by a microcontroller that switches the different interfaces and two controls that allow the adjustment of different temperature ranges," explained the scientists, noting that the solenoid valve turns on and the cold water It circulates through the coil, passing through a water collector when the temperature of the module exceeds 59 degrees Celsius. The heat exchanger located under the panel was thermally insulated with polyurethane foam and an aluminum foil behind the insulation.
The system was tested on the second level of the building of the local company Solaring, in the climatic conditions of the city of Bafoussam, in the western region of Cameroon. Temperature sensors were used to measure the different temperatures of the hybrid system, as well as the temperature of the water at the outlet of the exchanger. Current and voltage sensors were used to evaluate the performance of the photovoltaic modules. Measurements were made over four days at five minute intervals.
Scientists found that the PV/T system with Canadian Solar modules had the best overall efficiency, at 57.59%. With an average irradiation of 877W/m2, these modules achieved an average energy conversion efficiency of 16.8%, an average water thermal photovoltaic electrical efficiency of 18.89%, a 12.3% growth in energy yield , an average water thermal photovoltaic thermal efficiency of 38.7% and an average hot water temperature of 41 degrees Celsius.
For comparison, the Trina module achieved an average energy conversion efficiency of 16.0%, a water thermal photovoltaic electrical efficiency of 18.42%, an 11.8% growth in energy yield, an efficiency thermal photovoltaic thermal water of 39.1% and an average temperature of hot water of 41.5 degrees Celsius.
Felicity Solars panel had the worst performance, with an average energy conversion efficiency of 15.8%, a water thermal photovoltaic electrical efficiency of 17.02%, an 11.0% growth in energy yield, a photovoltaic thermal water thermal efficiency of 38.7% and an average hot water temperature of 41 degrees Celsius.
"This approach allowed us to recover part of the electrical power of the modules that is lost as heat, while determining the amount of hot water that a photovoltaic module can produce," the scientists conclude. "The prototype [that was] built and tested also allowed us to verify that the electrical performance of PV/T water systems also varies depending on the type and brand of solar module chosen."
The results of the tests can be found in the article " Experimental study on the electrical and thermal characteristics of a hybrid photovoltaic/thermal water solar collector model using photovoltaic solar modules of different brands " of photovoltaic/thermal solar water collector that uses photovoltaic solar modules of different brands), recently published in Energy Conversion and Management: X. |
