Author :
Eveloy, Valerie ; Rodgers, Peter ; Bojanampati, Shrinivas
Author_Institution :
Dept. of Mech. Eng., Pet. Inst., Abu Dhabi, United Arab Emirates
Abstract :
Despite the abundance of solar energy in the Middle East, the efficiency and reliability of photovoltaic (PV) modules is severely affected by elevated cell operating temperature, which reduces the effectiveness of sun tracking techniques. In this study the potential of water-cooling to improve the electrical performance of stationary and sun-tracked PV modules is experimentally investigated for application at off-shore oil and gas facilities in the Persian Gulf. In parallel with measurements of PV module electrical characteristics and operating temperature, global solar irradiation, ambient air and cooling water temperatures, wind velocity and relative humidity are also recorded. In autumn conditions in the United Arab Emirates (24.43°N, 54.45°E), water-cooling is found to reduce PV module operating temperature by up to 30°C relative to passive cooling conditions, depending on operating conditions. Using water-cooling, power output is enhanced for a significant portion of the day for fixed geographical South facing modules (e.g., 22% at solar noon, and 13% at 2 p.m.) relative to passive cooling, and even more significantly for sun-tracked modules (e.g., 20% at 2 p.m.). Sun tracking enhances power output by 16% and 24% for passively- and water-cooled modules, respectively, at for example 2 p.m. The incorporation of water-cooling and sun tracking is the most effective, with enhancements in output power of on order 40% at for example 2 p.m. relative to passively-cooled, fixed South facing operation. In winter conditions (e.g., December), modest reductions in operating temperature and improvements in electrical performance are obtained using water-cooling and/or sun tracking, which may not justify the associated capital and operating costs.
Keywords :
cooling; humidity measurement; photovoltaic power systems; power generation reliability; solar cells; solar radiation; temperature measurement; velocity measurement; December; Middle East; PV module electrical characteristics measurements; Persian Gulf; United Arab Emirates; ambient air temperatures; autumn conditions; capital costs; cooling water temperatures; electrical performance; elevated cell operating temperature; geographical South facing modules; global solar irradiation; offgas facilities; offshore oil; operating costs; passive cooling conditions; photovoltaic modules efficiency; photovoltaic modules reliability; photovoltaic solar module performance; power generation; relative humidity; solar energy; solar noon; sun tracking techniques; sun-tracked PV modules; sun-tracked modules; water-cooling potential; wind velocity; Cooling; Ocean temperature; Radiation effects; Sea surface; Sun; Temperature measurement; Water heating; Photovoltaic; thermal management; water-cooling;