Utilities tap water ‘microgrid’ tech for new supply – E&E News

As drought continues to strangle the American West, some small water providers are exploring new technologies to boost their supplies.

The technologies range in size and scope. One involves towing buoys off the coast of California that desalinate water and pipe it ashore. Another can recycle nearly all the water within an apartment building on site.

They are like electric microgrids for water. And experts say they provide a glimpse into a possible future that is drastically different from the past, when boosting water supply required large utilities — and often the federal government — to invest billions of dollars in infrastructure projects.

“The important thing is modularity,” said Newsha Ajami, director of urban water policy at the Stanford University Woods Institute for the Environment. “We are sort of getting into this era of moving away from building more centralized infrastructure-heavy systems to more modular and distributed solutions.”

Perhaps the most ambitious endeavor comes from the Santa Barbara, Calif.-based Ecomerit Technologies. Its plan calls for deploying “SeaWell Buoys” that will desalinate water at sea, then pipe it to water stations built along the coast. The stations are about the size of lighthouses, and from there, the water would be added to a local utility’s water supply.

The buoys themselves are about 15 feet in diameter, rise 6 feet above water and plunge 40 feet below. They’d be moored to the seafloor. The desalination process takes place below the surface, making it more cost- and energy-efficient than an onshore plant, where water is pumped in and pushed through a reverse osmosis system before brine is pumped back out.

“The beauty of this is you are not sucking in seawater to process on land, then half of it goes back out,” said Ecomerit founder Jim Dehlsen. “You are just delivering fresh water in — that’s two-thirds less energy.”

Each buoy would cost about $2 million to $4 million and would produce as much as 950 acre-feet per year, Ecomerit says. That puts the total price tag at about $2,000 per acre-foot, a few hundred dollars less than the going rate for onshore desalination plants.

Ecomerit has developed an ambitious proposal to deploy 204 of the buoys up and down the coast, connecting them to 56 of the lighthouse-like water stations by 2026. They’d produce some 200,000 acre-feet of water.

It sounds futuristic, but Ecomerit says it is working as quickly as it can as the state dives deeper into drought. It plans to deploy its first buoy in 2023, possibly near its home in Santa Barbara.

“There’s a need — an urgency,” said Peter Stricker of Ecomerit. “Where we …….

Source: https://www.eenews.net/articles/utilities-tap-water-microgrid-tech-for-new-supply/