Wednesday, February 1, 2012
Water Power: Out with the New, In with the Old by Zachary Shahan
Solar and wind energy are well-known renewable energy options that are quickly growing in use around the world. Both have seen record-breaking growth in the past few years. Tremendous growth is projected to continue in the years to come, as well. But solar and wind won’t provide the world with all of its energy needs. They may not be ideal for some locations, and they may need to be supplemented by other energy sources in some locations.
Other than the ubiquitous wind and the tremendously powerful sun, one of the most abundant natural resources on our planet is water, and flowing water carries a great deal of energy. Just think of the feeling you had when you walked into a medium- or fast-flowing river or stream, or decided to test your strength against a breaking wave.
While wave power, tidal power, ocean thermal power, and other “water power” options exist, this article only discusses the most readily available water power option today — small or micro hydro.
Small Water Power (or Micro Hydro) Potential
New micro hydro (aka microhydro or micro-hydro) could produce 30,000 megawatts of decentralized, local power in the U.S. alone, according to a 2006 study. To put that into perspective, that’s enough power for up to about 30 million homes.
“We keep telling lawmakers that there’s tremendous growth potential in the industry. We are far from tapped out,” Jeff Leahey, director of government affairs for the National Hydropower Association, says. “We can access existing infrastructure today and build tens of thousands of megawatts in communities around the country.”
The map below shows what percentage of a state’s electricity sales could be provided from new micro hydro.
All of this small hydro potential could be tapped with “run-of-river” projects (projects not requiring dams) or projects that make use of existing dams.
“There are over 81,000 dams around the U.S. and only 2,400 of them have any electrical generating capacity,” Stephen Lacey of Climate Progress reports. “Many of the power-less 78,600 dams are close to existing infrastructure, making it easier to build and maintain a project compared with a centralized wind or solar farm located far away from where the electricity is used.”
The question, however, is what technology will be able to capture that energy and efficiently turn it into electricity for a home, business, or community.