Among the main attractions of setting up bitcoin mines at the edge of the Arctic Circle is the natural cooling for computer servers and the competitive prices for Iceland's abundance of renewable energy from geothermal and hydroelectric power plants. Johann Snorri Sigurbergsson, a business development manager at the energy company Hitaveita Sudurnesja, said he expected Iceland's virtual currency mining to double its energy consumption to about 100 megawatts this year. That is more than households use on the island nation of 340,000, according to Iceland's National Energy Authority. "Four months ago, I could not have predicted this trend — but then bitcoin skyrocketed and we got a lot more emails," he said at the Svartsengi geothermal energy plant, which powers the southwestern peninsula where the mining takes place. "Just today, I came from a meeting with a mining company seeking to buy 18 megawatts," he said. At the largest of three bitcoin "farms" currently operating within Keflavik — called "Mjolnir" after the hammer of Thor, the Norse god of thunder — high metal fences surround 50 meter-long (164 foot) warehouse buildings stacked with computer rigs. The data centers here are specially designed to utilize the constant wind on the bare peninsula. Walls are only partial on each side, allowing a draft of cold air to cool down the equipment. | 
