Even the founders and an enthusiastic governor admit it sounds crazy: Charge up a train full of massive batteries with clean solar or wind energy out on the plains, then roll the trains to Denver or any other spot that’s low on power without using billion-dollar electrical lines.
The train track becomes the transmission line. “Trainsmission,” by the company’s coinage.
SunTrain, Gov. Jared Polis, Xcel Energy and national clean energy advocates said Monday the idea is ready, and if they land a $10 million federal grant, a demo project charging trains at Pueblo and plugging into the grid at Denver’s Cherokee power station could be ready by 2026.
SunTrain says each one of its train car-sized iron phosphate batteries holds enough power for 20,000 homes for an hour, or 1,000 homes for a full day. The first-of-its-kind demonstration in Pueblo would start with 20 battery-packed rail cars, with the electrical and rail technology eventually supporting 100-car battery trains providing temporary power for hundreds of thousands of people.
SunTrain’s first demonstration at Pueblo would charge a train full of batteries at the solar farms that have sprung up around the Comanche coal-fired power plant run by Xcel. The trains would then run 115-odd miles north to Denver’s Cherokee plant, which is a former coal-fired plant converted to natural gas generation by Xcel.
The initial trains would be diesel powered, but even those would still make the battery power some of the cleanest energy around, SunTrain officials said in a rollout at Xcel’s Cherokee plant in north Denver. Rail power is an efficient use of fossil fuels, and train-delivered electricity reduces carbon by about 88%, they said. As San Francisco-based SunTrain and partners begin to use electric locomotives that can themselves run on renewable energy, rail delivery of charged batteries would become a 100% carbon-free operation.
Fighting climate change, keeping the electric grid reliable and keeping energy affordable for consumers all require dozens of innovative renewable energy ideas, Polis said at the presentation.
“There’s lots of exciting technologies to be looked at,” Polis said. “Of course, not everything that entrepreneurs are trying will work out, but the fact that we have dozens of ideas being pursued that at least pencil out with projections on paper — we’re going to need some of those solutions.”
Colorado surpassed California and other states in the percentage of car sales for electric vehicles in the third quarter, Polis said, citing a new national analysis. Colorado being No. 1 in electric sales for the first time means the state more than ever needs reliable, affordable electric power, Polis said.
Xcel executives said they are continuing to push forward their multibillion dollar Colorado transmission upgrade called the Power Pathway, but it’s a years-long project for approvals and construction. Batteries on trains use existing infrastructure — the cost of running trains is variable, but the capital costs are small by comparison and improve as battery technology advances.
Railroads are willing to work with the newer lithium iron phosphate batteries because they are not flammable, and much less volatile than older lithium ion batteries, executives said. The newer batteries also use fewer rare-earth metals whose mining is causing environmental problems around the world. Hauling batteries can help replace business lost to the closure of coal-fired or oil-fired power plants around the nation.
SunTrain and other backers mentioned multiple scenarios where the battery trains could be attractive:
- Bridging deliveries of solar or wind energy not yet connected to a power grid, and at times of the day when urban areas see demand surges. Train-based batteries can store wind power generated at nighttime off-peak hours, and deliver it to substations or be parked as backup.
- Powering remote needs that are not on the grid but are near current or abandoned rail lines. Music festivals similar to Coachella have already expressed interest, SunTrain said.
- Providing new or backup power to artificial intelligence data centers without further stressing existing power plants or transmission lines. Some AI executives have even started pursuing their own nuclear power plants as a reliable source of energy as data centers explode.
SunTrain has been financed by venture capital so far. If the federal grant does not come through, SunTrain executives said they could seek more private capital or an alternate combination of research and development grants.
If the project proves out, SunTrain could have 100-car trains waiting at either end and run charged and discharged trains in either direction, every day, SunTrain co-founder and chief technology officer Chris Smith said. If the project fails, “it’s all on wheels,” Smith said, meaning the powerful batteries can be rolled elsewhere for other projects or uses.
Xcel is “well on its way” to stated goals of 80% renewable generation of Colorado power by 2030, and needs innovative ideas to get to 100% by 2050, said the company’s Colorado president, Robert Kenney.
“Crazy ideas are usually the ideas that solve crazy problems,” Kenney said. “And climate change is one of those.”