Hydro Green Energy, which wants to plumb America's waterways for electricity, has received $2.6 million in funding.
The company wants to create somewhat small, modular turbines and then set them down in arrays in waterways. Each turbine would be capable of harvesting 250 kilowatts of power. The size of the array would then depend on the size and power of the waterway.
It hopes to plant these arrays in Minnesota, Louisiana, Mississippi, and other states.
Many other companies, such as Ireland's OpenHydro, are building large machines that look like oil derricks for harvesting power. These larger machines go in the ocean.
Tidal power has a number of advantages over other renewables. For one thing, it's predictable. Computer simulations can calculate the amount of electricity that can be generated from tides decades in advance. Besides being predictable, tides are also constant, unlike wind or solar.
The bad part? It's still experimental. Most companies haven't even tested out full-scale prototypes yet. These machines will also have to survive in harsh, unpredictable environments. The impact on fishing fleets and marine life is also unknown. Commercial tidal power, however, should begin to start in a few years and will likely hit before commercial wave power, according to some experts.
Here's one interesting tidbit: The Quercus Trust was the lead investor. Quercus is also an investor in LiveFuels, which wants to make fuel out of algae, and some unusual lighting projects. It's one of those investment outfits that swings for the fences.