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InPipe Energy: Power through Pressure

It’s the new hydropower. Not dams, no reservoirs, just pipes. With help from Oregon State engineering researchers, an Oregon startup company is developing a system to generate carbon-free electricity from a previously untapped water source: the pipes under our streets.

InPipe Energy is taking advantage of the difference in pressure between the major arteries of water distribution networks and the smaller branches that feed homes and businesses. Water suppliers routinely use valves to reduce pressure from high to low, but the energy produced in that step dissipates like heat from a campfire.

In a community the size of Corvallis, enough energy might be available in the water system to power the equivalent of 200 homes, says Gregg Semler, company president and CEO.

After installation costs, “this is free energy,” adds John Parmigiani, Oregon State professor of mechanical engineering who led a project to test InPipe Energy’s technology. “The idea is to use some of that water to spin a turbine and produce electricity. Water is returned to the system at the right pressure for consumers. They would see no difference in their water pressure. It’s drop-dead simple.”

With financial support from Oregon BEST, which supports clean technology research, Parmigiani and Nick Aerne, engineering graduate student, worked with InPipe Energy to design and construct a prototype system at the O.H. Hinsdale Wave Laboratory on the OSU campus. They installed hydropower turbines in a loop parallel to a normal distribution line. At water pressures similar to those found in municipal water systems, they measured power output at startup, under continuous operation and at shutdown. The turbines achieved efficiencies between 60 and 80 percent.

“This test proves that InPipe Energy’s hydropower system is safe, reliable, efficient and can be a valuable tool to help water agencies reduce their operating costs and carbon footprint,” Semler says. “We’re using existing infrastructure to produce renewable energy. It’s predictable and low cost and has no environmental impact. Oregon BEST’s investment provided us the capital we needed to build and test our prototype and helped us achieve this critical commercialization milestone.”

Operations in the nation’s water infrastructure, including pumping and purification, consume about 6 percent of the total energy used in the United States. In California, where big agriculture distributes vast amounts of water for irrigation and food processing, the energy used approaches 20 percent.

Parmigiani and his students are continuing to look at improvements in the technology. Meanwhile, InPipe Energy is in discussions with water agencies and industrial companies on the next phase of commercialization.

About Tom Breunig (203 Articles)
Tom Breunig is principal at Cleantech Concepts, a market research firm tracking R&D projects in the cleantech sector. He is a technology industry veteran and former international marketing and communications executive who has worked with organizations in semiconductor design, water monitoring, energy efficiency and environmental sensing. He has spoken at numerous technology and energy conferences.
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2 Comments on InPipe Energy: Power through Pressure

  1. There is no explanation as to the source of the pressure being converted. Generally Water supplies rely on water towers to create “head pressure”in a water man. Sometimes this is supplemented by captive air tanks where a suitable bladder separates the water from a compressed ir charge which may need to be topped up on a regular basis. Pumps operate to fill the tanks to a normal level thereby compressing the Gas / air which gives up an inflate gate amount of space to the water rising thereby further impressing the air. So there is some energy source used to fill water towers by pumping a steady amount of water to the tower and the water level in the tank rises and falls per the demand of the system which declines during high demand daytimes and rises in the evenings. So in either situation you are using energy to produce water pressure in water mains. While you may be harvesting excess pressure that pressure is created by some other energy consumption. Very bizarre Alt renew scheme

    • Thanks, Tim. The point is that while yes, some form of energy was used to pump the water up to a higher point, this InPipe application leverages that pressure to create more electricity, whereas normally that pumping power would only have served one purpose — to get water up a hill. This is energy harvesting in the same way that you might collect industrial heat from a factory. The heat was generated by a power source but can be captured to create additional energy.

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