- SunTrain, a US-based energy transportation innovator, is tackling the challenge of renewable energy distribution with a novel solution: battery-powered trains rolling fully charged from sunny and windy locations to where the energy is needed.
The company was founded in 2021 on the back of the concept of shipping energy, in the same way oil and coal are shipped by rail for use in far-flung locations.
SunTrain aims to use the existing US rail network to move 120-wagon battery trains to deliver renewable energy. In its initial phase, each wagon will host a 9.6 MWh battery, weighing 80 tons. The total payload therefore is around 1.15 GWh, or enough to power the daily needs of 120,000 homes.
The envisaged idea is to charge from solar farms, and ship the green power to where it is needed. Essentially, the idea creates a bridge before transmission lines are installed, which can take 5-10 years from planning and approval to installation and commissioning.
So far, the company has tested a custom 750 KWh train car, fully charged with solar energy at SunTrain’s San Francisco testbed and transported over 6,500 miles on the Union Pacific network in California.
A further announcement is pending, with SunTrain previewing “a partnership with a major utility and a Department of Energy national laboratory” to develop a 20-railcar, 384 MWh grid-connected pilot project. The project would move wind and solar energy 125 miles to be discharged at a location to reduce gas peaker plant use and emissions.
In an interview with ESS News, SunTrain CTO Christopher D. Smith discussed the vision and technology behind the plan.
“SunTrain reimagines energy transmission and storage by leveraging existing rail infrastructure to deliver scalable, grid-connected solutions that accelerate decarbonisation and renewables,” said Smith. The aim is to utilize the network of over 100,000 miles of rail lines across the United States to move grid-ready electricity, similar to how coal and other energy sources are currently transported.
While the core of SunTrain’s technology comprises customised battery containers mounted on rail cars, the most significant challenge concerns charging and discharging infrastructure
“Getting 2 GWh of power to discharge in four hours was no easy feat,” said Smith. Developing a seamless and durable charging/discharging system that would allow our trains to entirely charge/discharge simultaneously without removing the batteries from the railcar was our biggest challenge. At the same time, this capability is critical for SunTrain’s strategy of targeting peak demand periods in the wholesale energy markets.
“This is the standard block of time used by grid operators utilising energy storage systems in the wholesale market,” said Smith.
Economics
The company’s current levelised cost of energy (LCOE) is approximately $60/MWh and decreasing, which opens the door to operating profitably within the volatile energy market. SunTrain projects the ability to sell energy at prices ranging from $100 to $150 per MWh, depending on regional market conditions. The company is also investigating alternative revenue streams, such as PPAs, and participating as an EPC contractor in build-own-transfer projects, as demonstrated by a partnership with Xcel Energy.
Addressing potential regulatory concerns, Smith affirmed, “No, regulatory hurdles have been carefully researched and primed. There are no regulatory barriers that we’re aware of. Energy already runs over the freight railroad network, and we’re just a different form.”
The company is also raising money via an equity-raising crowdfunding scheme.
Author: Tristan Raynor
This article was originally published in pv magazine and is republished with permission.
