SubtleGuest writes: The National Energy Administration has approved a plan allowing China Datang Corp, the nation's second biggest power producer, to construct a $659 million wind farm facility that will generate 400 megawatts. At $0.10/kWh, it will pay for itself in about two years. $659,000,000 to generate 400,000,000 watts of power, or 400,000 kW. That's a constant income of $40,000 at $0.10 per kWh. Divide $659 million by $40K and it's 16,475 hours. Divide that by 24 and it's 686 days. Divide that by 365.25 and it's 1.9 years.