Pictured – Navajo Generation Station via US Bureau of Reclamation
January 22nd, 2020 by Tina Casey
Whelp, that was fast. No sooner does the notorious coal-fired Navajo Generating Station shut its doors, when a massive renewable energy project jumps in to take its place. We’re talking about the proposed Navajo Energy Storage Station in Arizona, and it’s not just any old renewable energy project. It’s a 10-hour, 2,200 megawatt system, which puts it in the long duration storage category, which is something the US Department of Energy has been lusting after quite lustily.
Navajo Generation Station via US Bureau of Reclamation
Long Duration Energy Storage In The Time Of Trump
To be clear, the so-dubbed NESS project is still in the proposal and permitting phase. If all goes according to plan, it will be online in 2030 — just in time to absorb new wind and solar development in the area.
If and when NESS does go online, it could pull the rug out from under future plans for gas-fired power plants. The developer, Daybreak Power, is anticipating that NESS will provide wind and solar power to Los Angeles, Las Vegas, and Phoenix for 10 hours, lasting from peak daytime hours and into the night.
That 10-hour energy storage capability is key. The Energy Department has a whole initiative dedicated to long duration storage, which it defines as a minimum of 10 hours and up.
If you’re guessing that’s a recipe for decarbonizing the electricity grid, run right out and buy yourself a cigar.
That’s right, regardless of the Commander-in-Chief’s pro-coal rhetoric, the Energy Department has been promoting the coal-killing combo of renewables and energy storage hand over fist all throughout his tenure (for that matter, the recently impeached President* seems to have lost interest in coal, but that’s a whole ‘nother can of worms).
The Energy Department’s ARPA-E office for cutting edge R&D explains:
“Long-duration energy storage systems address grid needs beyond those covered by daily cycling. Such systems could provide backup power for several days, improving grid resiliency, or allow for the integration of even larger amounts of intermittent renewable sources like wind and solar.”
ARPA-E notes that long duration systems also have a role in daily cycling, which is where a 10-hour system like the NESS project would fit in.
“Such systems could help shape the output from individual wind and solar installations, improving the reliability of these resources and thus greatly increasing their value to the grid,” ARPA-E explains.
Massive Pumped Hydro Energy Storage Project For Arizona
For those of you new to the topic, the former Navajo Generating Station was the largest power plant in the US west, and one of the nation’s single largest carbon emitters, too. It was built in the 1970s and finally closed for business last year.
That finally brings us to the workings of the proposed NESS project. As a pumped hydro storage system, it will require the construction of a reservoir, to be built on the Cummins Plateau above Lake Powell. The project will deploy wind and solar power to pump water from the lake up to the reservoir during daily periods of low use. As needed, the water will flow by gravity down through a generating station to produce electricity.
For those of you new to the pumped hydro topic, there is a general advantage in terms of environmental impacts. Given the right site, an upper reservoir can be built near an existing water body without the need to build a new dam or otherwise interfere with a natural waterway.
Because the system recycles water, the upper reservoir also does not create additional stress on groundwater resources.
Daybreak is pretty confident that the Cummings Plateau site addresses concerns over impacts on wildlife habitat, but that will be a matter to hash out among numerous stakeholders. Daybreak lists the National Park Service, the Navajo Nation and other First Nations, public interest groups, water users, and recreationists among the parties with a say in the matter.
Who’s Gonna Pay For All This?
The big question in all of this is financing, and that’s where things get interesting. Pumped hydro plays a big role in the Energy Department’s plans for the electricity grid of the future. However, electricity markets are shifting so fast that 8-10 year projects like pumped storage can’t keep up without an assist.
The Energy Department already has an initiative under way to help reduce the cost of pumped hydro, and Daybreak also has a trick or two up its sleeve.
The company is planning to make use of the existing 16-mile, 500-kilovolt transmission line that previously connected the Navajo Generating Station to the grid, which cuts a great deal of time and expense out of the picture.
Daybreak also plans on attracting investors with the prospects for future wind and solar development in the region as well as the overall economic development involved in creating hundreds of new clean tech jobs.
Our friends over at Utility Dive anticipate that NESS could make use of the now-familiar PPA financing platform to fund the project, especially if it can prove that there is a demand for bulk storage.