Seite - 38 - in Clean Water Using Solar and Wind - Outside the Power Grid

38 Clean Water Using Solar and Wind: Outside the Power Grid diesel-generated power is about twice as high as the average footprint from grid-connected power in Africa. Despite the low cost of solar PV there is still an unfavourable competition with diesel generators. One important reason is lack of financing possibilities (see also Chapter 12). Diesel-generated power is two to three times more expensive than solar PV and the fuel cost is a significant contributor. For solar PV the up-front cost is higher while the fuel is free. So, even if diesel-generating power is more expensive to operate in the long run, diesel generators are cheap to buy. 3.5 SOLAR PV GLOBAL EXPANSION The energy available from solar radiation is huge. The global average solar radiation received by the average m2 can in one year produce the same amount of energy as a barrel (159 litres) of oil, 200 kg of coal or 140 m3 of natural gas. The solar energy obtained directly from the sun is termed solar radiation. There are two types of solar energy technologies: photovoltaic (PV) and thermal collectors. A PV cell will produce electricity directly from the solar radiation. Solar thermal collectors have been used for a long time for domestic heating and for providing hot water. The term solar irradiance is the measure of power from the sun over a certain area, typically measured in W/m2. Solar insolation is a measure of the energy from the sun and is averaged over a long time, and expressed in Ws/m2 per day or kWh/m2 per year. The use of the two terms across literature is not fully consistent. Global installed capacity for solar-powered electricity has seen an exponential growth, reaching around 227 GWp (gigawatt peak electric) at the end of 2015 (WEC, 2016, Chapter 8). At the end of 2016 320 GWp had been installed (Fraunhofer, 2016). It produced 1% of all electricity used globally. Solar PV installations are certainly not distributed equally over the continents; they are led by China, India, Germany and the United States (IEA, 2016a). Figure 3.5 shows that major solar installations have been made in regions with relatively less in terms of solar resource (Europe and China), while potential in high-resource regions (Africa and the Middle East) remains untapped (WEC, 2016, Chapter 8). There is a huge potential for solar PV in Africa, developing Asia and South America, where sunshine is abundant. This is further illustrated in Chapter 8. Downloaded from https://iwaponline.com/ebooks/book-pdf/520710/wio9781780409443.pdf by IWA Publishing user