Pilot project could turn Southern Nevada Water Authority into hydropower producer
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| This rate-of-flow control valve on Southern Nevada Water Authority's water delivery system is one of three sites to be retrofitted with small hydropower units in a pilot project to harness its built-in power supply. |
Since 9 percent of Nevada's electricity comes from hydropower, it was natural for Southern Nevada Water Authority to see potential energy in its regional water distribution system and to contact the Colorado River Commission of Nevada to help turn that potential into power.
Founded in 1991 by seven local water purveyors, SNWA owns and operates the Las Vegas metropolitan area water treatment and delivery system. The CRC provides the electrical energy to power SNWA's water system and, for the past few years, has managed the water authority's energy portfolio with the goal to integrate more clean energy sources.
As the drinking water supplier for all of southern Nevada's local water agencies, "The authority is acutely aware of the pressures on water resources in the region, and we are totally committed to running a sustainable operation," said J.C. Davis, SNWA's public information coordinator.
Equipment replacement creates clean energy source
Harnessing the power of the water moving through its conveyance system was one way SNWA believed it could improve its energy efficiency. Small hydropower units could perform the same function as rate-of-flow control valves while capturing the otherwise wasted energy and converting it to clean electricity. ROFC valves maintain the desired pressures and flows at certain locations on the water delivery system.
"On one hand, SNWA had the goal of using more renewable energy," observed Davis. "On the other, we had this built-in power supply that could be tapped with relatively inexpensive equipment and installation; we even had funding through our capital budget. So we approached CRC about doing a pilot project."
The idea of turning ROFC points into electricity generators intrigued the commission. "Basically, they were talking about making some changes to existing infrastructure to turn wasted energy into clean, usable electricity," recalled CRC Renewable Resource Manager Eric Dominguez.
More generation sites possible if pilot succeeds
The project, currently in the feasibility stage, involves retrofitting three existing ROFC valves and building one new facility. All the proposed sites are near existing power stations and pumping facilities, so the energy would be produced and used close to the load center.
The generating capacity per station ranges from 500 kW to 3 MW. The total generating capacity at the four sites could reach 5 MW, based on flow and pressure projections. Another eight to 10 more sites on SNWA's own and its purveyor's systems are candidates for conversion if the pilot program proves successful. The total potential generation could exceed 20 MW. At this time, the water authority is the only customer for the power they hope to produce with the hydro network. "It's not going to make us energy independent," noted Davis, "but 20 MW is nothing to sneeze at, either."
Plan offers additional benefits in emissions reduction
The same can be said for the plan's environmental impact. Based on 1 MW of installed capacity, electricity generated from the units would displace the following emissions annually:
- 10 million pounds of carbon dioxide (approximately as much as 1,314 acres of trees absorb per year)
- 28,200 pounds of nitrogen oxide
- 27,600 pounds of sulfur dioxide
CRC expects the feasibility study to be completed by the first quarter of 2003. If all goes well in the construction stages, the new hydro unit would go online by 2004, with the retrofitted units following six months to a year later. "A lot of details still need to be worked out at this point," Dominguez admitted, "but the project offers so many benefits it's hard not to get excited about it."
The hydropower project reflects SNWA's dedication to environmentally responsible management. That may mean a comprehensive recycling policy and a company car fleet of hybrid and electric vehicles, or it may take the form of an innovative proposal to produce renewable energy. "We evaluate all our operations for sustainability. If they are not sustainable, we look for ways to change them," Davis explained. "When you weigh that priority into all your decisions, it's amazing how close you can get."
