California utility turning water pressure into electricity

East Bay Municipal Utility District (EBMUD) in California is piloting a forward-looking plan to harness water pressure within its system to generate electricity.

EBMUD is partnering with renewable energy supplier InPipe Energy to install a system that use the flow of water within its network of pipes to produce cost-efficient electricity. The electricity powers an on-site pump station and any excess can be sold back to the electric utility to offset EBMUD’s energy costs.

“We’re seeing the impacts of climate change today through extreme weather events, more severe droughts, and increasing wildfire risk,” said EBMUD General Manager Clifford Chan. The utility provides drinking water for 1.4 million customers and wastewater treatment for 740,000 customers in the San Francisco area. 

“We are taking aggressive steps to reduce our carbon footprint, contribute to the fight against climate change, and demonstrate effective and practical solutions toward that goal,” he added. “EBMUD’s board of directors has made this a priority with a goal of achieving carbon neutrality by 2030.”

The pilot program uses InPipe Energy’s Hydro XS system (pictured above), an in-conduit hydroelectric system that works like pressure regulating valves installed in EBMUD’s water distribution system.

“We’ve developed a system that basically replicates the functionality of a control valve, but instead of wasting pressure, it produces renewable energy,” said Gregg Semler, CEO and founder of InPipe Energy. “East Bay MUD got really excited about this concept because it really addresses their focus on reducing energy costs and getting to net zero.”

Chan explained that InPipe Energy’s micro-hydro turbine technology harnesses flowing water to spin a turbine inside the pipeline and generate hydropower using the same principles as at its dams, but on a much smaller scale.

“EBMUD is the first utility in California to install InPipe Energy’s technology,” Chan said. “We will evaluate the performance and economics of the pilot to determine if this site or other locations can offer a cost-effective source of zero-emission energy.”

The returns, so far, have been positive. Semler said EBMUD’s system has generated twice the amount of energy than was predicted. Other U.S. water systems also are beginning to install energy recovery systems.

“Whatever’s coming down that pipe, we take it, but what we do is we convert pressure, we take out pressure,” Semler said. “We don’t change the flow, but we take out pressure. That’s how you create hydroelectricity.”