The ocean may supply Canada with power for the first time if the Canadian company B.C. Hydro proceeds with plans to build wave-energy plants in British Columbia. Although a few such plants exist in Europe and others are being tested in Washington state, the ocean is a relatively untapped energy source. The Canadian plants would produce between three and four megawatts of electricity, enough to power up to 4,000 homes. B.C. Hydro will make a final decision on the plants in November.