The December 2022 issue of IEEE Spectrum is here!

Close bar

New York City to Explore Electricity from Water Mains

It sounds like a nifty idea, but will it ever be much more than that?

2 min read
New York City to Explore Electricity from Water Mains

It sounds so sensible, you have to wonder why everybody isn't already doing it: Tap the excess pressure found in many urban water mains to drive small turbines that could feed electricity into the grid, block-by-block. Often such pressure has to be relieved by means of specially installed valves that do no work. Why not exploit it to generate power?

It took a New York City wireless company executive, musing idly about emergency power shortly after 9/11, to dream up the idea of electricity from water mains. The startup he founded and leads, Rentricity, has been attracting attention and interest locally. It has obtained modest R&D funding from the New York State Energy Research and Development Authority (NYSERDA) and is a tenant of the  New York University Polytechtechnic Institute Incubator that was started by the New York City Accelerator for a Clean and Renewable Economy. On 1 May, NYC Mayor Michael Bloomberg signed into law a city council resolution calling on New York to do an 18-month study of the feasibility of widely deploying electricity-from-water-main technology throughout the city.

The city, which gets all its drinking water from reservoirs that at are much higher elevations upstate, has a water distribution system that is inherently highly pressurized. As such, it would seem to be ideal for what Rentricity is proposing to do. It is not, however, the site of the first test installation. That honor goes to Keene, N.H., a town close to that state's southern border and Boston's high-tech periphery. Rentricity has also installed a 30-kilowatt generator at a reservoir near Pittsburgh; though that setup is in a water distribution system, it is basically a standard low-head hydro installation, and not an example of the power from water mains concept.

Could Rentricity turn out to be a company that is better at PR than engineering? To judge from its website, the opposite may be the case. The listing of its executive leadership makes a credible impression. The videos promoting its work, on the other hand, leave a good deal to be desired in terms of production values.

The Conversation (0)
This photograph shows a car with the words “We Drive Solar” on the door, connected to a charging station. A windmill can be seen in the background.

The Dutch city of Utrecht is embracing vehicle-to-grid technology, an example of which is shown here—an EV connected to a bidirectional charger. The historic Rijn en Zon windmill provides a fitting background for this scene.

We Drive Solar

Hundreds of charging stations for electric vehicles dot Utrecht’s urban landscape in the Netherlands like little electric mushrooms. Unlike those you may have grown accustomed to seeing, many of these stations don’t just charge electric cars—they can also send power from vehicle batteries to the local utility grid for use by homes and businesses.

Debates over the feasibility and value of such vehicle-to-grid technology go back decades. Those arguments are not yet settled. But big automakers like Volkswagen, Nissan, and Hyundai have moved to produce the kinds of cars that can use such bidirectional chargers—alongside similar vehicle-to-home technology, whereby your car can power your house, say, during a blackout, as promoted by Ford with its new F-150 Lightning. Given the rapid uptake of electric vehicles, many people are thinking hard about how to make the best use of all that rolling battery power.

Keep Reading ↓Show less