Page - 10 - in Clean Water Using Solar and Wind - Outside the Power Grid

10 Clean Water Using Solar and Wind: Outside the Power Grid a few kW to several hundred MW. Solar PV is at this moment probably the most attractive option for mini-grids (see also 3.2) for small villages (REN21, 2017a). Renewable energy delivered by solar photovoltaic (PV) or wind will have a profound impact on water delivery and water treatment over the next decades. Any domestic user will require two kinds of energy: electric energy for illumination, machines, pumps, water treatment units and other equipment and thermal uses of solar energy for (1) process heat (including cooking), (2) ambient comfort, depending on the actual location. We will describe how three kinds of renewables can satisfy these needs: solar photovoltaic (PV), wind power and solar heating. It should be noted that the direct use of solar energy for cooling via thermal processes has been tested in several situations, but so far it does not work satisfactorily. Biogas is an important and environmentally friendly source of energy, and many rural areas depend on it. In this book we refer to biogas as a by-product of used water treatment but will not specifically consider the production of biogas as an energy source. We purposefully exclude some energy technologies, like geothermal energy, concentrating solar thermal energy and large-scale wind energy. In fact, the growth of bioenergy, concentrating solar energy and geothermal energy represented only 4% of renewable energy capacity growth in 2016 (IEA, 2017b). We will show the potential of small-scale solutions that realistically can be used by individual households as well as small villages or a subdivisions of a city. Naturally, small-scale hydro can be considered an alternative energy source. This is already practised in regions with water resources but is not available in water-scarce areas. Regions with water scarcity or insufficient sanitation are certainly not areas where hydropower is an alternative. For the ongoing discussion we will exclude hydropower since our focus will be towards regions with water scarcity. 1.4.3 Providing water using renewables Water is the critical element for a decent life and sustainable growth. Once the very basic needs connected to electric power are met, such as lighting and low-load production, new avenues open up. Renewable energy technology is already used to meet energy demand in many Downloaded from https://iwaponline.com/ebooks/book-pdf/520710/wio9781780409443.pdf by IWA Publishing user