The decision by Warren Buffett ’s utility company to order about $1 billion of wind turbines for projects in Iowa shows how a drop in equipment costs is making renewable energy more competitive with power from fossil fuels. Turbine prices have fallen 26 percent worldwide since the first half of 2009, bringing wind power within 5.5 percent of the cost of electricity from coal, according to data compiled by Bloomberg. MidAmerican Energy Holdings Co., a unit of Buffett’s Berkshire Hathaway Inc., yesterday announced an order for 1,050 megawatts of Siemens AG wind turbines in the industry’s largest order to date for land-based gear. Wind is the cheapest source of power in Iowa, and the deal indicates that turbines are becoming profitable without subsidies, according to Tom Kiernan , chief executive officer of the American Wind Energy Association trade group. That’s a boost for suppliers including Siemens, […]