https://www.citylab.com/environment/2018/01/portlands-drinking-water-is-powering-the-grid/550721/
by Alastair Boone, January 17, 2018, CITYLAB
Portland, Oregon—known to some as “Bridge City”—has an intimate relationship with the water that flows beneath it. During hot summer months, residents cool off by floating down the Willamette River. Its iconic bronze drinking fountains (also known as Benson Bubblers) have been gushing with cool, clean water during daylight hours since 1912. And most recently, LucidEnergy—a Portland-based startup that launched in 2007—has discovered a way to use the city’s drinking water to generate electricity without any negative environmental impacts.
Since 2015, the city of Portland has been partnering with LucidEnergy to install electricity-generating turbines in its gravity-fed water pipes. A new video produced by the Van Alen Institute, in collaboration with CityLab, shows how the system works.
As water flows through the pipes freely, the turbines spin, collecting excess energy that is then purchased by Portland General Electric, and put on the city’s power grid. Portland has installed 50 feet of so-called “LucidPipes,” which generate an average of 1,100 megawatt-hours of electricity every year. That’s enough renewable energy to power about 150 homes.
That may not seem like much. But according to Laura Wisland, a senior energy analyst for the Union of Concerned Scientists, for cities aiming to reduce their reliance on fossil fuels in a cost-effective way, every little bit counts.
“If a city is making this investment because they have committed to being even more aggressive than state requirements for clean electricity, that’s a significant impact,” she said.“I think any electricity provider that’s interested in relying on carbon free electricity should diversify the types of resources they invest in as much as possible, to mitigate any potential risk that one of those supplies may not be as available as expected.”
And unlike the hydropower systems that are installed in dams across the country, Portland’s system uses existing infrastructure, which allows it to avoid killing fish and other marine life, or otherwise significantly altering aquatic habitats.
LucidEnergy has also installed hydropower pipes in a few other cities around the world, including Riverside, California, and Johannesburg, South Africa. But what’s keeping LucidPipe technology from being installed in cities across the U.S.? For one, the geography that surrounds a city determines how useful in-pipe hydropower can be. Portland sources the majority of its water from Bull Run Watershed, which sits in the mountains above the city. That means that gravity does the work of pulling the water down the pipes and dispersing it throughout the city. “It’s a net positive to generation because it doesn’t require any electricity to pump the water through,” Wisland said, “Obviously that’s not going to be the case in every single municipal water supply system.”
Replacing existing infrastructure with LucidPipe also costs money, and requires coordination between a given city’s electrical and water utilities. But there are some offsetting financial benefits, too. While Portland’s hydropower project cost about $1.7 million, it is expected to produce $2 million in clean energy over its 20 year contract.
“The city is very energy conscious. Wise use of water is always something that’s in the front of our minds,” Stan Vande Berge, a principal engineer at the Portland Water Bureau, said in the video. “It’s kind of the DNA that we have here.”
Van Alen Sessions is presented by Van Alen Institute with CityLab. Season Three, “Autonomous Infrastructure,” is directed and produced by Lucy Wells. The series is made possible with support from the National Endowment for the Arts, and is supported, in part, by public funds from the New York City Department of Cultural Affairs in partnership with the City Council. Connect with Van Alen Institute on vanalen.org.
