Steam plants are expensive, but nothing compared to a large hydro electric plant. Let me put this into perspective for you... The fans on the cooling towers at Browns Ferry Nuclear Plant consume the entire electric output of Norris Dam. You can find pictures of both on the Web. Dams are majestic, impressive structures, but they're more for flood control and water supply than cranking out megawatts. If you want power, get a modern gas turbine and run the exhaust into a heat recovery steam generator to drive a steam turbine and turn a generator. Only the government can afford to build a dam these days because they don't answer to investors who want a return on their money.