How much does U S consume fossil fuels and renewables

United States is still the worlds largest energy consumer. Despite the growing popularity of renewable energy sources such as solar power, wind power and biofuels, fossil fuels are still the dominant energy sources in United States and satisfy most of the nations energy demand.

The recent data shows that fossil fuels currently account for 84% of nations energy demand. Oil still accounts for approximately 40% of nations energy demand, while coal is the major source of US electricity accounting for around 49% of total US generated electricity. The third member of fossil fuel triad, natural gas, currently supplies around 23% of US energy demand, with many energy experts expecting natural gas share to grow in years to come, especially after the ever-growing shale gas extraction.

These numbers clearly show that fossil fuels are still the most important energy sources in United States, and that renewable energy industry still has plenty work ahead in order to challenge the dominance of fossil fuels.

Hydropower and biomass are currently the most important renewable energy sources in United States, wind is also looking quite good, while solar energy sector is fast developing.

Hydropower currently satisfies around 7% and biomass around 4% of nations energy demand. In the period from 2000-2010 wind power was the fastest growing renewable energy source in United States, and nation has even set a goal of achieving 20% of electricity coming from wind by 2020. If U.S. really wants to achieve this goal it will have to put a lot more emphasis to offshore wind energy.

The much talked about solar power is more making headlines in media instead of actually having significant impact in nations energy use. Many Americans believe in solar power as the best possible renewable energy option but despite the huge popularity solar power currently satisfies less than one percent of nations energy demand. This is mostly because solar panels are still relatively expensive, and somewhat inefficient compared to efficiency of fossil fuels.

US is global leader in installed geothermal capacity but this doesnt mean much when it comes to energy use because geothermal energy currently meets less than 1% of nations energy needs, which is way too little given the geothermal potential of some US states such as California and Nevada.

Given the current situation it is logical to expect that fossil fuels will continue their dominance when it comes to nations energy use simply because renewable energy needs time to develop desired efficiency and costs. Without reaching competitiveness in terms of efficiency and costs renewable energy cannot seriously challenge fossil fuels, even with the strong federal and local support.

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Liquefied Air to Store Energy on U K Grid

IEEE Spectrum has an article on a variant of compressd air energy storage being trialled in the UK - Liquefied Air to Store Energy on U.K. Grid.

U.K.-based Highview Power Storage last week said that it has been awarded an £8 million grant from the U.K. Department of Energy and Climate Change to build a commercial-scale facility that uses liquified air to store energy. Highview is already running a smaller pilot plant, but the full-scale version will be able to store enough energy to deliver five megawatts of power for three hours. That puts it on a scale that would entice utilities to use the technology, says company CEO Gareth Brett. ...

Liquid air energy storage is similar to compressed air energy storage in that air is compressed and released to store and then generate power. With Highview’s technology, though, ambient air is compressed, then cooled and liquified. That liquefied air, which is almost -200 °C, is stored in large tanks.

When power is needed, the liquid air is released and pumped to high pressure. That causes the liquid to evaporate, turning it into a high-pressure gas which is then run through a turbine to generate power. The planned demonstration plant will be located at a waste processing center. Heat from the waste plant’s gas turbines, which run on captured landfill methane, will be piped in to improve the efficiency of the evaporation process.

One of the advantages of liquid air storage is that it uses off-the-shelf equipment. The tanks for storing liquid air, for instance, are the same as those used in the industrial gas industry.

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