World's Cheapest Offshore Wind Farm to Power 600,000 Homes. Sweden's Vattenfall set a world record for the lowest price ever paid for offshore wind power. The state-owned energy company bid EUR 49.9 (or $54) per megawatt-hour to develop the Danish Kriegers Flak, a 600-megawatt offshore wind farm in the Baltic Sea, about 15 kilometers off the Danish island Møn. Kriegers Flak. For comparison, the average cost of offshore wind is around $126 per megawatt-hour.