Page - 182 - in Clean Water Using Solar and Wind - Outside the Power Grid

182 Clean Water Using Solar and Wind: Outside the Power Grid a power rating of more than 30 MW. Small hydropower is typically less than 10 MW. Intermittent electricity: electric energy that is not continuously available due to external factors that cannot be controlled. Sources of intermittent electricity include solar and wind power. Their electrical output cannot be used at any guaranteed time to meet fluctuating electricity demands. Inverter (solar): a power electronics device that converts power from solar PV modules or batteries in DC form into alternating form (AC) at a required frequency and voltage output. This can be used by a local, off-grid network. The inverter circuit’s AC output voltage waveform is not a sine wave but usually a square wave or a distorted sine wave. Levelised cost of energy/electricity (LCOE): measure of the total cost (for example, measured in cost per kWh) to produce electricity, including capital cost, operating, maintenance and fuel costs. The cost is discounted back to a common year using a discount rate. Levelised cost of storage (LCOS): the average cost to store and discharge energy (cost per kWh). The LCOS is calculated over the entire lifetime of the storage and includes the capital and operational costs. The cost is discounted back to a common year using a discount rate. Off-grid renewable energy: renewable energy generation that is not connected to a larger electricity system or network. Osmosis: the spontaneous net movement of solvent molecules (such as water molecules) through a semi-permeable membrane into a region of higher solute concentration (such as seawater), in the direction that tends to equalise the solute concentrations on the two sides. Photovoltaic: production of electric current at the junction of two  substances exposed to light. A photovoltaic cell (PV cell) is a specialised semiconductor diode that converts visible light into direct current (DC). Some PV cells can also convert infrared (IR) or ultraviolet (UV) radiation into DC electricity. Reverse osmosis: type of membrane filtration (see osmosis). Downloaded from https://iwaponline.com/ebooks/book-pdf/520710/wio9781780409443.pdf by IWA Publishing user