While subsidies for solar energy helped make green energy more available, the sector is supported by unsustainable economy policies, a British official said. Germany in 2010 installed more solar power than the entire world added to its grid in 2009. Solar power in the United States and Japan, meanwhile, is double 2009 levels, a U.N. panel found in July. Europe for the first time last year added more solar power to its grid than wind energy, though across the board, wind power experienced the most expansion. British Energy Minister Greg Barker, in an article for the Guardian newspaper, writes that solar energy is a \"vital component\" of an emerging green economy. He said costs for solar technology are down by around 30 percent since a subsidy was put in place in April 2010. \"But the uncomfortable truth is that, with overgenerous subsidies failing to keep pace with plummeting costs, this boom has been built on unsustainable foundations,\" he writes. He warns that the $1.3 billion secured for a feed-in tariff scheme is close to running dry. \"Used wisely the tariff scheme offers the potential for millions of consumers to generate more of their own green electricity and break the grip of the over-dominant energy companies,\" he writes.