Avery Thompson for Popular Mechanics:  The first tidal generator in North America has gone online this month in the Bay of Fundy, and is expected to generate enough electricity to power 500 homes.

While most hydro generators harness the energy of falling water, or the energy of the waves, tidal power uses the energy of the high and low tides. At the Bay of Fundy in Nova Scotia, which has the largest tides in the world, that energy is being harnessed to generate 2 megawatts of electrical power.

In the Bay of Fundy, the difference between high and low tide is about 56 feet. Approximately 115 billion tons of water flow in and out of the bay every tidal period. Two renewable energy developers, OpenHydro and Emera, decided to build turbines on the seafloor that could harness that power.  Cont'd...