Renewable energy law is a particular kind of energy law, and relates primarily to the transactional legal and policy issues that surround the development, implementation, and commercialization of renewable sources of energy, such as solar, wind, geothermal and tidal. Renewable energy, (RE) law also relates to the land use, siting, and finance issues encountered by developers of renewable energy projects. Renewable energy support laws Renewable energy law also encompasses policies that relate to renewable energy and legislative instruments that further encourage its growth. Feed-in tariffs One such form of legislation is feed-in tariffs, which provide economic incentives to the developers of renewable energy projects by setting a fixed price for the sale of energy produced from renewable sources. Feed-in tariff laws also provide financial certainty, are more cost effective and less bureaucratic than other support schemes such as investment or production tax credits, quota based renewable portfolio standards (RPS), and auction mechanisms. In addition, the feed-in tariff generates more competition, more jobs, and more rapid deployment for manufacturing; it also does not pick technological winners, for instance between more mature wind power technology versus solar photovoltaics technology. Renewable Portfolio standards This type of law is in force in 37 of the States within the United States, as well as Australia and a minority of European nations. It works by fixing the quantity of renewable electricity that must be produced, and leaving it to the market at what price this extra renewable electricity will be produced. This form of legislation typically employs a tradeable certificates mechanism, where 1 Megawatt Hour of electricity is equivalent to 1 renewable energy certificate. Sector Regulation The Role of the Sector Regulator is specified in the enabling legislation. For example, regulatory oversight of feed-in tariff programs is essential, whether the price is based on a predetermined number (and with some maximum capacity), an auction/bidding process, or avoided cost. In each case, the regulator monitors activities to ensure abuses do not arise. How external (environmental and health) costs are factored into program evaluation is partly dependent on the enabling legislation (or executive order). If the law establishes Renewable Portfolio Standards, the energy regulator will need to oversee the system and evaluate its effectiveness in meeting RE objectives. Generally, some other agency is responsible for certifying the generators and handling the certification system. The sector regulator has a number of roles and responsibilities for operationalizing and implementing RE.