Seite - 105 - in Clean Water Using Solar and Wind - Outside the Power Grid

Solar PV 105 The  open circuit voltage will typically decrease by 0.4% for every degree K deviation from the reference, while the short circuit current will increase by 0.05% for every degree increase. Since the voltage depends more on temperature than the current, the power will decrease as the temperature increases. Example 8.2: Power Requirement for Irrigation Pumping Temperature will influence the required solar power for pumping. The required hydraulic energy is multiplied by a temperature factor 1 1 0− −α( )T Tcell where α is the PV module temperature coefficient, which is of the order 0.45%/°C (Campana et al., 2016). Tcell is the solar cell temperature and T0 a reference temperature of 25°C. So, with a cell temperature of 50°C the required power will increase with around 13%. Global warming because of climate change may increase the risk of lower efficiency, since the PV cells operate best at around 25°C. Efficiency loss caused by increasing temperature has been studied in Saudi Arabia (Adinoyi & Said, 2013). A module temperature increase from 38°C to 48°C resulted in 10.3% losses in efficiency. This corresponds to a temperature coefficient α = 0.9%/°C (now based on the reference temperature 38°C). The annual loss of energy due to high temperature was estimated at around 10%. 8.3.4 Floating PV systems In some areas of the world, notably in China, Japan, South Korea, India, the UK, France, Italy, Brazil, Portugal and the U.S., there has been a move towards floating solar panel technology, in which the panels float on the surface of water. This will have some appealing consequences including that the panels do not take up valuable space on land. Japan has implemented more than 55 MWp of floating solar across 45 plants. This includes the floating solar panels on the Solar power output decreases with increasing temperature. Downloaded from https://iwaponline.com/ebooks/book-pdf/520710/wio9781780409443.pdf by IWA Publishing user