Throughout the U.S., dozens of proposed photo voltaic, wind, and battery tasks—encompassing hundreds of gigawatts of potential energy—are backlogged as they wait to be allowed to plug into the power grid. And, even in areas the place renewable vitality tasks are already on-line, their output is often heavily curtailed. This clear vitality bottleneck stems from the truth that, as demand for renewable vitality rises, the U.S. isn’t building new transmission strains fast enough to move massive quantities of unpolluted vitality from level A to level B.
Now, there’s an organization seeking to tackle that drawback with a easy but radical resolution: Placing renewable vitality into big batteries and transporting these batteries by practice.
SunTrain is a San Francisco-based firm based by inexperienced vitality developer Christopher Smith, who now serves as the corporate’s president and chief know-how officer. The concept, he explains, is to make use of the present U.S. freight practice system—which covers round 140,000 miles of terrain—to deliver renewable vitality that’s being curtailed by transmission bottlenecks to the areas that want it most.
SunTrain is at the moment engaged on a pilot undertaking that may run between Pueblo, Colorado, and Denver. If it’s accredited by regulators, Smith says, he expects the pilot could possibly be off the bottom in simply two years.
Present challenges to transporting renewables
Clear vitality is the fastest-growing supply of electrical energy within the U.S. Based on a report from American Clean power, 93% of the brand new vitality capability final 12 months was photo voltaic, wind, and battery storage. The difficulty, Smith says, is that transmission line infrastructure lags far behind the speed of unpolluted vitality progress.
“The USA wants 300,000 miles of latest transmission strains, like, proper now. That’s the quantity that we want instantly to maintain up with present demand,” Smith says. “It’s additionally estimated that, to achieve 100% renewables, in addition to the electrification demand that we’ll have by 2050, we’ll want over one million miles of latest transmission strains by 2050. Presently, we’re constructing lower than 1,000 miles a 12 months.”
Constructing new transmission strains is difficult for a variety of causes, together with environmental rules, the time it takes, and the truth that any new strains must cross hundreds of miles of privately owned land.
In Colorado, for instance, Smith says there’s plenty of renewable vitality within the state’s southeast nook, which flows by way of the grid to Pueblo. Nevertheless, as a result of there’s not sufficient transmission line capability between Pueblo and Denver, a lot of that energy can’t finally be used.
“As soon as that renewable vitality will get to Pueblo, there’s not sufficient transmission line capability to get it into downtown Denver,” Smith says. “In order that vitality principally will get curtailed—a flowery phrase for being wasted.”
Till now, the expensive development of latest transmission strains has been the primary resolution that’s obtainable. However Smith says this dialogue overlooks a useful resource that’s been used to move vitality for nearly 200 years: railroads.
“The freight railroad community already strikes just about each single type of vitality identified to man that’s utilized in an actual method: pure gasoline, coal, oil, ethanol, biomass, spent nuclear waste, varied fossil fuels, and the listing goes on and on,” Smith says. “So there’s this big quantity of overlap of our nice railroad community and our electrical methods already. There isn’t any purpose why we can’t be transferring battery trains over the freight rail community like we transfer each different type of vitality.”
SunTrain’s resolution
For its pilot undertaking, SunTrain is partnering with Xcel Power, Colorado’s largest electrical utility. Xcel owns a coal plant in Pueblo (Comanche Producing Station) and a pure gasoline plant in Denver (Cherokee Producing Station) which are each set to be decommissioned throughout the subsequent a number of years. By way of a collaboration with SunTrain, these vegetation may doubtlessly be re-powered with battery saved vitality.
Smith says SunTrain would use the present substation inside Comanche Producing Station—which already has in depth railroad infrastructure from its historical past as a coal plant—to cost its batteries from Pueblo’s bottlenecked grid. In the course of the day, Smith says, the vitality will possible be 100% renewable. Then, the batteries could be transported to Denver and the vitality offloaded on the Cherokee Producing Station onto Denver’s grid. (Charging and discharging take between 4 and 6 hours every, and the 139-mile journey from Pueblo to Denver takes about 5 hours by practice.)
“A substation can flip vitality right into a format that may cowl lengthy distances with out dropping a lot vitality,” Smith says. “A substation may also flip electrical energy generated from an influence plant right into a format that can be utilized by native houses and companies. For SunTrain’s functions, the Pueblo substation permits us to get the electrical energy formatted correctly for our batteries whereas additionally collectively accessing all the varied renewable vitality mills within the area.”
SunTrain’s proposed railcars might be manufactured from 20-foot delivery containers, every of which will hold about 40 tons of batteries. The corporate designed proprietary charging and discharging methods that “permit the vitality to stream proper from the place it’s generated, whether or not it’s a photo voltaic array or a substation, proper below the batteries on the railcar,” Smith says. Then, as soon as the practice arrives at its vacation spot, the discharging system would equally permit the vitality to stream proper off the batteries. The entire course of is designed in order that the batteries by no means truly should be faraway from the practice.
In an interview with the podcast In the Noco, Smith mentioned SunTrain’s first era railcars are designed to match the freight railroad’s present requirements for coal trains, to make sure that the system itself doesn’t want to vary something to ensure that SunTrain to return to market. Primarily based on these parameters, every practice might be constructed at between 8,000 and 9,000 ft lengthy, with the capability to hold round two gigawatt hours of energy in whole. That’s sufficient to energy a metropolis of 100,000 for a full day.
Smith says the crew has already examined a proof-of-concept practice on a number of journeys amounting to greater than 10,000 miles on the Union Pacific community, touring from SunTrain’s San Francisco testbed to discharge areas throughout California, Nevada, and Colorado. Now, the corporate is ready for Colorado’s Public Utilities Fee to approve Xcel’s expenditure of about $125 million to start development on the pilot undertaking.
“We examined the know-how, the feasibility, made positive the mechanical requirements have been there,” Smith says. “Our manufacturing companions can ship whole unit trains of those—which means 200 rail automobiles of batteries that might carry about 1.75 gigawatt hours of vitality. So this isn’t one thing that’s far-off, coming within the pipeline, or needing some type of technological breakthrough. That is an instantly executable thought. It simply wants the capital.”
