 In 2001, the Australian government introduced a mandatory renewable energy target (MRET) designed to ensure renewable energy achieves a 20% share of electricity supply in Australia by 2020.The MRET was to increase new generation from 9,500 gigawatt-hours to 45,000 gigawatt-hours by 2020.The MRET requires wholesale purchasers of electricity (such as electricity retailers or industrial operations) to purchase renewable energy certificates (RECs), created through the generation of electricity from renewable sources, including wind, hydro, landfill gas and geothermal, as well as solar PV and solar thermal.