Hydroelectric Power in Los Angeles? It should happen in about a year.
A dam across the Los Angeles River won't generate the power. There's nothing like a trickle of water that flows through a concrete tube and figures prominently in ‘70s cop show car chases involved. Instead, a local water agency will install a micro-hydrokinetic power system from Rentricity that will effectively generate 225 kilowatts of electricity from pressurized water flows controlled by the agency. Specifications for L.A.'s Flow-to-Wire system for L.A. are being written and could be complete in nine months to a year. Another 30-kilowatt system is being designed for a municipal water agency near Pittsburgh.
Granted, these two experimental generators will barely provide enough power to light up a block in an urban neighborhood. And Rentricity has been plugging the concept for a while. But the two trials (and one completed earlier in Connecticut) will serve to prove the concept works, says president Frank Zammataro, who estimates that hundreds of megawatts could be harvested from public and private water facilities in the U.S.
Worldwide, Zammataro estimates that 25,000 potential sites for micro hydro exist. Potentially, the market for micro-hydro equipment could amount to $30 billion. The company already has six other proposals in the pipeline.
The key is that man-made pressurized water flows are not going away. Water agencies – along with heavy-duty private sector water consumers like oil refineries and agribusiness – have to pressurize water to purify it or move it. Approximately 19 percent of the electric power in the state of California is consumed in processing and moving water, said Chris Spain, co-founder of HydroPoint Data Systems, an irrigation monitoring company, in an interview earlier this year.
To get water to a particular elevation, for instance, a water agency might have to pressurize water to 67 pounds per square inch, said Zammataro. Once the water gets to the desired location, a large percentage of that pressure likely dissipates. Rentricity essentially wants to capture that pressure to create electricity before it disappears.
In the L.A. trial, for instance, Rentricity's system will sit in a transfer station between two reservoirs. In the Pittsburgh trial, the equipment will be at a mandated release point, i.e., a stream. Municipal agencies have to release some water in their reservoirs into streams to keep the environments that depend on the water flows alive. The equipment – technically called a reverse pump – will just extract some of the pressure. Right now, much of this pressure is bled off through a device called a pressure reduction valve.
"[Water treatment facilities] were put in place for the management of water, not for energy recovery," he said. "We don't take away the need for a pressure reduction value but we take a lot of the pressure."
The payoff for the system takes about five to seven years, he added. Buyers also quality for renewable energy credits as well as investment tax credits.
If it's so good, how come it's not popular now? For companies like General Electric, micro-hydro systems might be too small to spend much time on, he theorized. Water agencies, meanwhile, "have an energy efficiency mentality but they really don't know about generating electricity," he said. He's got a point: Water agencies are even considered stodgy within the highly conservative utility industry. New regulations, however, will force them to improve energy efficiency even more.
Micro-hydro systems can be used with both clean water systems that deliver water to homes and businesses as well as wastewater. After a storm, the city of Boston has about one billion gallons of runoff, according to Zammataro. Interestingly, water expert Laura Shenkar of the Artemis Group says the best way to think about the water industry is to consider runoff first.
"We're going to have to get a lot smarter" about managing water, said Zammataro.