Fuel were present at the sites. As a fuel, wood has remained in use up until the present day, although it has been superseded for many purposes by other sources. Wood has an energy density of 10–20 MJ/kg. Recently biofuels have been developed for use in automotive transport (for example Bioethanol and Biodiesel), but there is widespread public debate about how carbon efficient these fuels are. Fossil fuels are hydrocarbons, primarily coal and petroleum (liquid petroleum or natural gas), formed from the fossilized remains of ancient plants and animals by exposure to high heat and pressure in the absence of oxygen
Economics of nuclear power plants significantly different evaluation of the risk of investing in new nuclear power plants. Two of the four EPRs under construction (the Olkiluoto Nuclear Power Plant in Finland and Flamanville in France), which are the latest new builds in Europe, are significantly behind schedule and substantially over cost. Following the 2011 Fukushima Daiichi nuclear disaster, costs are likely to go up for some types of currently operating and new nuclear power plants, due to new requirements for on-site spent fuel management and elevated design basis threats. Although the price of new plants in China is falling rapidly, approaching $1500/kW (or about