Within a few years, Colorado's largest utility plans to use renewable energy as its main source of power. Doing that could require it to break new ground on one of the trickiest problems for solar and wind power: Where do you store it?
So, the new plan from Xcel Energy would include some of the largest batteries ever built in the United States, along with hundreds of megawatts of new solar and wind power.
Here's what they would build:
The plan calls for Xcel to deactivate the coal Comanche plants in Pueblo county, replacing them with about 525 megawatts of solar panels, plus storage. The coal plants would be shut down by 2025.
The Pueblo facility would include the largest battery in the country if it were built today, according to Jason Burwell, vice president of the Energy Storage Association -- although a bigger one is coming to Southern California.
Adding batteries is a crucial step for renewables. They allow the utility to capture energy when the wind's blowing or the sun's shining, and then dispense it when it's needed. Nationwide, the amount of energy storage could triple in 2018 alone.
The Colorado plan also calls for:
- 72 megawatts of solar panels in Park County
- 110 megawatts of solar, plus storage, in Adams County.
- 800 megawatts of new wind turbines on the plains east of Denver, in Kit Carson and Cheyenne counties
- 169 megawatts of turbines near the Wyoming border in Weld County.
In all, the proposal would cost $2.5 billion, according to Xcel. It would take the utility from 29 percent to 55 percent renewable power in Colorado.
The plan isn't pie-in-the-sky.
Xcel received more than 400 bids from companies that want to build renewables -- and the proposed costs came in shockingly low, according to Amelia Myers, an energy expert for Conservation Colorado.
The proposal is based on "Xcel’s analysis of all the bids — looking at how it fits, how it can get the cheapest energy for its customers, and also looking at the future of how it’s going to be generating electricity," she said.
She thinks that part of the rush is due to the potential expiration of federal tax credits in the years ahead.
"They’re getting really good federal benefits by having these online within the next four years," she said. Plus, demand is growing. "I think Xcel has seen also that its customers in terms of cities, larger tech companies, they’re asking for this product."
Xcel needs the approval of the Colorado Public Utilities Commission before it can move forward, which could happen in September. The PUC will assess whether the proposal ultimately benefits Coloradans and utility customers.
