Comments on: A startup that squeezes electricity out of city water

By: joan mccaffrey

joan mccaffrey — Tue, 04 Dec 2012 20:13:37 +0000

In the State of California, nearly 30% of electricity is used for the movement of water. Pumping water up to reservoirs and then capturing the generation as it went back down the pipe network has been used as a method for balancing the load on the grid for a long time. Hydro power, likewise, is used for balancing the grid against intermittent renewables such as wind and solar in places such as Bonneville Power Authority. We should see a lot more generation from water treatment plants as they take a new look at assets they have had but did not capitalize on.

By: Frank Zammataro

Frank Zammataro — Wed, 28 Nov 2012 16:38:39 +0000

Innovyze has a large array of water services including some of the monitoring that Rentricity can supply as part of an energy recovery installation. However, I do not believe they provide energy recovery. Innovyze would be a good partner to Rentricity.

By: Partha

Partha — Wed, 28 Nov 2012 15:08:54 +0000

How this compared to the likes of Innovyze that actually reduces the supply pressure?

By: Frank Zammataro

Frank Zammataro — Wed, 28 Nov 2012 13:39:49 +0000

Hi Michael,

Glad to see you are still tracking Rentricity. I would be happy to give you an update which should demonstrate not only market progress, but technology development. Feel free to reach out to me directly!

Best regards,

Frank

By: Ucilia Wang

Ucilia Wang — Wed, 28 Nov 2012 06:26:38 +0000

Rentricity’s goal is to offset the energy used to pressurize the water/operate the water plant. The company claims that its project in Keene has created an energy neutral water treatment plant.

By: michael kanellos

michael kanellos — Tue, 27 Nov 2012 21:59:53 +0000

They have to pressurize it to process it. They are recovering some of the energy used in that first, necessary step and coverting it to electricity. It’s like waste heat, but instead it is waste pressure. The issue with Rentricity is that they have been saying they same exact thing since 2007 with very little progress. The customer base–municipal water agencies–is the worst you can imagine. They are always one step away.

By: Al

Al — Tue, 27 Nov 2012 20:46:50 +0000

Maybe I’m missing something, but doesn’t it take energy to pressurize the water in the first place? Therefore making this a net-zero (best case, likely a net-negative) source of energy?

I’m sure I’m way off, but that’s the impression I get from this.