Query: Electricity rates are 40 percent higher in states that have required utility companies to use a certain amount of renewable energy such as solar power.

Relevant passages:
Smart grid <=SEP=> A smart grid is an electrical grid which includes a variety of operational and energy measures including smart meters , smart appliances , renewable energy resources , and energy efficient resources . Electronic power conditioning and control of the production and distribution of electricity are important aspects of the smart grid .   Smart grid policy is organized in Europe as Smart Grid European Technology Platform . Policy in the United States is described in § 17381 .   Roll-out of smart grid technology also implies a fundamental re-engineering of the electricity services industry , although typical usage of the term is focused on the technical infrastructure .

Wind power in the United States <=SEP=> Wind power in the United States is a branch of the energy industry that has expanded quickly over the latest several years . For calendar year 2016 , wind power in the United States amounted to 226.5 terawatt-hours , or 5.55 % of all generated electrical energy .   As of January 2017 , the U.S. nameplate generating capacity for wind power was 82,183 megawatts ( MW ) . This capacity is exceeded only by China and the European Union . Thus far , wind power 's largest growth in capacity was in 2012 , when 11,895 MW of wind power was installed , representing 26.5 % of new power capacity .   In 2016 , Nebraska became the eighteenth state to have installed over 1,000 MW of wind power capacity .  Texas , with over 20,000 MW of capacity , had the most installed wind power capacity of any U.S. state at the end of 2016 . Texas also had more under construction than any other state currently has installed . The state generating the highest percentage of energy from wind power is Iowa . North Dakota has the most per capita wind generation . The Alta Wind Energy Center in California is the largest wind farm in the United States with a capacity of 1548 MW . GE Energy is the largest domestic wind turbine manufacturer .

Solar power <=SEP=> Solar power is the conversion of energy from sunlight into electricity , either directly using photovoltaics ( PV ) , or indirectly using concentrated solar power . Concentrated solar power systems use lenses or mirrors and tracking systems to focus a large area of sunlight into a small beam . Photovoltaic cells convert light into an electric current using the photovoltaic effect .   Photovoltaics were initially solely used as a source of electricity for small and medium-sized applications , from the calculator powered by a single solar cell to remote homes powered by an off-grid rooftop PV system . Commercial concentrated solar power plants were first developed in the 1980s . The 392 MW Ivanpah installation is the largest concentrating solar power plant in the world , located in the Mojave Desert of California .   As the cost of solar electricity has fallen , the number of grid-connected solar PV systems has grown into the millions and utility-scale solar power stations with hundreds of megawatts are being built . Solar PV is rapidly becoming an inexpensive , low-carbon technology to harness renewable energy from the Sun . The current largest photovoltaic power station in the world is the 850 MW Longyangxia Dam Solar Park , in Qinghai , China .   The International Energy Agency projected in 2014 that under its `` high renewables '' scenario , by 2050 , solar photovoltaics and concentrated solar power would contribute about 16 and 11 percent , respectively , of the worldwide electricity consumption , and solar would be the world 's largest source of electricity . Most solar installations would be in China and India . Currently , as of 2016 , solar power provides just 1 % of total worldwide electricity production but growing 33 % per annum .

Carbon tax <=SEP=> A carbon tax is a tax levied on the carbon content of fuels . It is a form of carbon pricing . Carbon is present in every hydrocarbon fuel ( coal , petroleum , and natural gas ) and converted to carbon dioxide and other products when combusted . In contrast , non-combustion energy sources -- wind , sunlight , geothermal , hydropower , and nuclear -- do not convert hydrocarbons to . is a heat-trapping `` greenhouse '' gas which represents a negative externality on the climate system ( see scientific opinion on global warming ) . Since GHG emissions caused by the combustion of fossil fuels are closely related to the carbon content of the respective fuels , a tax on these emissions can be levied by taxing the carbon content of fossil fuels at any point in the product cycle of the fuel .   Carbon tax offers social and economic benefits . It is a tax that increases revenue without significantly altering the economy while simultaneously promoting objectives of climate change policy . The objective of a carbon tax is to reduce the harmful and unfavorable levels of carbon dioxide emissions , thereby decelerating climate change and its negative effects on the environment and human health .   Carbon taxes offer a potentially cost-effective means of reducing greenhouse gas emissions . From an economic perspective , carbon taxes are a type of Pigovian tax . They help to address the problem of emitters of greenhouse gases not facing the full social cost of their actions . Carbon taxes can be a regressive tax , in that they may directly or indirectly affect low-income groups disproportionately . The regressive impact of carbon taxes could be addressed by using tax revenues to favour low-income groups .   A number of countries have implemented carbon taxes or energy taxes that are related to carbon content . Most environmentally related taxes with implications for greenhouse gas emissions in OECD countries are levied on energy products and motor vehicles , rather than on emissions directly .   Opposition to increased environmental regulation such as carbon taxes often centers on concerns that firms might relocate and/or people might lose their jobs . It has been argued , however , that carbon taxes are more efficient than direct regulation and may even lead to higher employment ( see footnotes ) . Many large users of carbon resources in electricity generation , such as the United States , Russia , and China , are resisting carbon taxation .

Energy policy of the United States <=SEP=> The energy policy of the United States is determined by federal , state , and local entities in the United States , which address issues of energy production , distribution , and consumption , such as building codes and gas mileage standards . Energy policy may include legislation , international treaties , subsidies and incentives to investment , guidelines for energy conservation , taxation and other public policy techniques .   Several mandates have been proposed over the years , such as gasoline will never exceed $ 1.00 / gallon ( Nixon ) , and the United States will never again import as much oil as it did in 1977 ( Carter ) , but no comprehensive long-term energy policy has been proposed , although there has been concern over this failure . Three Energy Policy Acts have been passed , in 1992 , 2005 , and 2007 , which include many provisions for conservation , such as the Energy Star program , and energy development , with grants and tax incentives for both renewable energy and non-renewable energy .   There is also criticism that federal energy policies since the 1973 oil crisis have been dominated by crisis-mentality thinking , promoting expensive quick fixes and single-shot solutions that ignore market and technology realities . Instead of providing stable rules that support basic research while leaving plenty of scope for American entrepreneurship and innovation , congresses and presidents have repeatedly backed policies which promise solutions that are politically expedient , but whose prospects are doubtful , without adequate consideration of the dollar costs , environmental costs , or national security costs of their actions .   State-specific energy-efficiency incentive programs also play a significant role in the overall energy policy of the United States .  The United States refused to endorse the Kyoto Protocol , preferring to let the market drive CO2 reductions to mitigate global warming , which will require CO2 emission taxation . The administration of Barack Obama has proposed an aggressive energy policy reform , including the need for a reduction of CO2 emissions , with a cap and trade program , which could help encourage more clean renewable , sustainable energy development . Thanks to new technologies such as fracking , the United States has in 2014 resumed its former role as the top oil producer in the world .