Contributed by Hannah Hickey
In the past, hydropower developers scouting out the perfect location for power-producing devices relied on a combination of maps and stream gauges - and a lot of legwork. Even seasoned professionals describe knocking on the doors of strangers living near promising creeks. But a new tool allows people to find a promising site for hydropower development from the vantage point of their office chairs. The Virtual Hydropower Prospector, launched in July, displays the power potential of every stream in the country, and shows prime locations for development.
"This is an information tool that will assist people to develop the next generation of hydropower in the United States," says project manager Douglas Hall, an engineer at the U.S. Department of Energy's Idaho National Laboratory, in Idaho Falls.
The INL hydropower group evaluates the tool with team leader Doug Hall (left).
Funded by DOE's Wind and Hydropower Technologies Program, VHP is a free, Web-based geographic information system (GIS) application that can be used to locate and evaluate potential hydropower projects. No special software or license is required to use the application. Hall anticipates that users may include homeowners who want to generate electricity from a nearby stream; municipalities or Indian tribes that want to produce some of their own power; hydropower-development companies looking for new project sites; and utility companies seeking to expand their renewable-energy portfolios.
The application brings together topographic, hydrologic, demographic, infrastructure, land-use and water-energy resource information never before gathered in one place. INL collaborated with scientists at the United States Geological Survey, who used elevation maps and precipitation data to estimate the power potential of every stream. While many companies use computerized maps, Hall says, it would be difficult for a single private company to develop such a comprehensive tool.
Some members of the hydropower community are already prospecting using VHP. Wayne Krouse, president of Hydro Green Energy in Houston, says his company is happy with the new tool. "We're a start-up company and we don't have a lot of resources," Krouse says. "This application allows us to immediately identify a potential hydropower resource that's within a mile or two of a substation. It allows us to identify where the resource potential is greatest, and where it's most cost effective."
On the computer screen, VHP looks like a SimCity computer game for hydropower enthusiasts. The user can choose from sites that could be developed using conventional high-power technologies or a range of low-power technologies: conventional turbines, unconventional systems and microhydro, small-scale technologies that can power up to a few dozen homes. A map then shows every location in the country that would support that type of development.
The Web-based Prospector zooms to the scale of an individual stream, highlighting prospective locations for hydropower development.
Clicking on a potential site brings up the length of the stream, its gross power potential, flow rate and hydraulic head. If a stream section is a feasible project site, the application provides additional development information. A table at the bottom of the screen displays distances to the nearest road, population center, power line and substation. It also shows whether the stream is located in an area where development would be unlikely, such as a national park, components of the National Wild and Scenic River System or environmentally sensitive area.
Hydropower developers used to drive around remote areas looking for sites, says Trey Taylor, president of Verdant Power in Arlington, Va. Taylor recalls consulting kayakers and fishermen to find the best spots for the company's underwater turbines.
"VHP helps us identify where there are load pockets, it helps us locate where there are transmission lines, and thirdly, in the absence of velocity measurements, it gives some idea of where there are big flows," Taylor says. "The beauty of what they've done is this allows those of us in hydropower development to begin seeing where there could be opportunities for more development."
All of VHP's feasible sites fall under a broad category called "small hydropower" - plants that generate less than 30 megawatts, or enough to power about 25,000 homes. These systems generally do not dam the river or stream. They may include a high-tech version of a waterwheel, a propeller-like turbine or a submerged windmill. One type of technology even looks like a wing flapping in the current. Small hydropower systems have fewer environmental impacts than dams, Hall says. In addition, he believes they can provide greater reliability to local utility customers, because they usually generate electricity close to where it's being used.
VHP caps investigations led by INL on the potential for expanding hydropower in the United States. A recent study by Hall and his colleagues found the United States could roughly double hydropower output by building small hydroelectric plants. The study identified 130,000 project sites, using a set of feasibility criteria. Together, these sites could generate 30,000 megawatts of electricity. Currently, some 2,500 hydroelectric plants nationwide (including those with large dams) generate between 25,000 and 35,000 megawatts of electricity.
With the VHP, Hall hopes not only to show people what is out there, but to provide the tools to take action. "We wanted to go beyond just providing a wall chart map," Hall says. "VHP provides maps of where the sites are, but it also adds another dimension: attribute information you can't show on a map. This way, people can do their own assessments about the feasibility of developing a site."