June 21, 2023: Trains with Batteries: A Viable Backup Power Solution for the Grid. As the demand for electricity in the United States continues to rise due to the growing use of electric cars and the shift to electric building energy, the country’s power grid is facing increasing pressure. At the same time, the effects of climate change are causing more extreme weather events. While events like the 2020 heatwave and subsequent blackouts in California are uncommon, they happen more frequently, requiring utilities to be prepared.
A recent study from the U.S. Department of Energy’s Lawrence Berkeley National Laboratory suggests that batteries on trains could be a flexible and cost-effective solution for backup power during such extreme events. Previous research has already demonstrated the potential role of rail-based energy storage in meeting daily electricity needs.
However, the Berkeley Lab researchers wanted to explore whether rail-borne batteries could provide reliable backup power during exceptional events and whether this scenario was feasible using the existing U.S. rail network.
The study found that the extensive U.S. rail network, which spans nearly 140,000 miles, can transport energy where it’s needed during extreme events. This approach could be more cost-effective than building new infrastructure. The researchers compared the cost of deploying batteries on trains for low-frequency events with the investment costs of stationary energy storage and transmission lines.
They found that rail-based energy storage could be more cost-effective for distances up to approximately 250 miles than stationary battery banks, which are used for supply gaps that occur less than 1% of the year. For longer distances, over 930 miles, rail becomes cheaper than transmission lines for low-frequency events, potentially saving the power sector significant costs.
The study highlights the potential benefits of rail-based mobile energy storage in areas like New York State, where robust freight capacity and transmission constraints exist between clean energy generation in upstate regions and downstate load centers. In some cases, it may be advantageous for multiple states to share the capacity provided by a rail-based battery bank, similar to an insurance policy covering a broad geographic region.
While there are regulatory and infrastructure challenges to address, such as interconnections to integrate the power from trains into the grid and establishing appropriate policies for mobile energy assets, the researchers believe that rail-based energy storage could complement existing infrastructure like transmission lines.
The study’s findings offer a high-level overview of the benefits of rail-based mobile energy storage for the current grid and climate conditions. Rail-based energy storage could become an even stronger component of the overall energy mix as the future brings more electrification, fluctuating renewable energy, and increased extreme events.
The William and Flora Hewlett Foundation provided funding for this research.