Most wave-power systems sit on the water's surface. Not CETO, which is mounted on the ocean floor in 50 to 150 feet of water. Rows upon rows of balloons sway back and forth and up and down in response to the wave motion above. This motion drives a pump just below the balloon that sends high-pressure seawater to shore. From here, the seawater can be diverted to a desalination plant, which requires high pressures to pump saltwater through a series of membranes, or to a power plant. In the power plant, the pressurized water spins a turbine and produces electricity for the grid. Construction on the first commercial-scale farm is set to begin by 2010. When finished, the 300 units should produce 50 megawatts of electricity, or about enough to power 30,000 households.