Nevada's original net-metering law for renewable-energy systems was enacted in 1997 and amended in 2001, 2003, 2005 and 2007. Systems up to one megawatt (MW) in capacity that generate electricity using solar, wind, geothermal, biomass and certain types of hydropower are generally eligible, although systems greater than 100 kilowatts (kW) in capacity may be subject to certain costs at the utility's discretion. Systems must be designed to offset part or all of a customer-generator's electricity requirements.