VentureBeat

Hydro Green Energy, another player in the burgeoning hydrokinetic sector, has just capped a $2.6 million first funding round led by the Quercus Trust.

The Houston-based company holds 13 preliminary permits from the Federal Energy Regulatory Commission (FERC) for projects in Alaska and Mississippi; it expects its first project, on the Mississippi River in Minnesota, to begin operations in late August. Another four projects that will be built downstream of existing U.S. Army Corps of Engineers’ dams in Mississippi will generate close to 100 megawatts.

Similarly to Verdant Power, which we wrote about a few days ago, Hydro Green’s turbine arrays don’t require large structures or a damming of water to work. The arrays are mounted on barges, which allows for the raising and lowering of individual units — greatly facilitating control and maintenance operations. They also have a relatively benign environmental impact and, unlike bottom-anchored turbines, have little effect on the riverbed. Each turbine array has a maximum average capacity of 250 kW.

In 2006, a NASA-sponsored study estimated that Hydro Green’s turbine design would produce at least 240% more power than similar technologies in the U.S. and the U.K. — a finding that was corroborated by two independent energy consulting groups, Concepts NREC and Hatch Energy.

Another hydrokinetic firm, Massachusetts-based Free Flow Power, just unveiled a $3 billion plan to install thousands of in stream electric turbines at 59 sites along the Mississippi River. CEO Daniel R. Irvin believes the turbines will generate 1,600 megawatts, enough to power 1.5 million homes. The turbines, which will be made of carbon fiber or another lightweight composite material, will be attached to pilings in the river bed.

The project is facing close scrutiny from state and federal environmental regulators and the Army Corps, which have both expressed concerns about the turbines’ impact on river navigation and the river’s wildlife. This extra oversight has done little to dampen activity in the sector, however, with Hydro’s funding round just the latest in a series of investments over the last year.