Green Science Image Gallery
Green Science Image Gallery

Bourne Energy's RiverStar is small and easy to install. See more green science pictures.

Image courtesy of Bourne Energy

Energy efficiency and environmental protection are two of the biggest issues facing the world today. Recent efforts have focused on shifting energy production away from environmentally unfriendly fossil fuels such as coal and oil, toward cleaner, renewable energy sources like solar, wind and hydropower.

Hydropower is currently the largest source of renewable energy in the United States. Hydroelectric plants supply about 6 to 8 percent of all the electricity produced in this country [source: Nelson]. Typically, hydroelectric power is harnessed by building a dam on a river and storing the water in a large reservoir. As the water flows through gates in the dam, it turns turbines, which are connected to the generators that produce energy.

Hydroelectric power plants are effective energy generators, yet they tend to be large and expensive to build. One company says it has created a smaller, more portable, and even more environmentally friendly way to produce clean and efficient hydropower. Bourne Energy, based in Malibu, Calif., has designed a power system that harnesses energy not from dams, but directly from flowing rivers.

Bourne Energy's RiverStar harvests energy all along a river, rather than at one site, so it is smaller and easier to install [source: Bourne Energy]. RiverStar modules are placed in arrays of 20 units across the width or length of a river. They are held in place by high-tension steel cables that are attached to either side of the river. Each floating module is made up of a turbine that looks like an upside-down windmill, as well as a stabilizer, energy absorber, mooring system and energy conversion system. Flowing water passes through the turbines, and as they spin, they collect energy, which drives a generator module.

Read on to learn just how much energy RiverStar might be able to produce.