Last month, on the high prairie east of its hometown, Denver-based Peak Energy powered up what it says is the United States’ and “the first ever fully passive megawatt-hour scale battery storage system” anywhere in the world.
Peak’s 3.5-MWh project marks a big step forward for the electrochemical battery chemistry that many experts believe is the most viable lithium ion battery, which today dominates the energy storage market for discharge durations shorter than four hours.
Sodium-ion batteries’ allure is growing amid volatile commodity pricing and an on-again, off-again trade war between the United States and China affecting lithium-ion batteries.
“Lithium-ion costs remain highly sensitive to raw material prices, meaning that spikes in lithium, nickel, or cobalt prices could improve sodium-ion’s relative competitiveness,” she said.
“Expectations among [sodium-ion battery] manufacturers have cooled as LFP prices continue to trend downward, leading to a reduction in our expectations for sodium-ion to scale,” she said.
China charges ahead on sodium-ion
As debate rages over sodium-ion batteries’ place in the global energy mix, sodium-ion battery manufacturers and developers are moving forward — particularly in China.
China’s sodium-ion push is reminiscent of its decade-long strategy to dominate the market for lithium-ion battery precursors, materials and components. Its head start leads some Western analysts and entrepreneurs to conclude that China will also dominate the sodium-ion battery market, at least for grid-scale energy storage applications.
Others, including Peak Energy, are making a different bet. As production scales up in China and eventually the United States, they expect sodium-based battery producers to carve out a sizable share of the rapidly-growing stationary storage market worldwide — not only in China.
High-profile failures sow doubts in U.S. market
Yet even sodium-ion skeptics like Stanford University scientist Adrian Yao, lead author on a questioning the technology’s near-term commercial potential, warn against reading too much into Natron’s failure. Yao said earlier this month that Natron may have been too early to its chosen niche: high-powered, short-duration batteries for data centers and large industrial facilities.
Where ‘sodium excels’
According to Unigrid cofounder and CEO Darren Tan, less energy-dense but higher-power sodium battery modules are indeed better suited to shorter-duration applications. Those include backup and demand response for commercial and industrial users, a niche Natron aimed to fill with its first products.
That’s one reason Tan believes sodium-ion is not in a position to challenge lithium-ion in grid-scale stationary storage. He also blames China’s head start on commercialization and its ruthlessly competitive clean tech culture, which drives prices far below levels Western manufacturers can match.
In the longer run, Tan said sodium-ion chemistry could eat into lithium’s dominance in behind-the-meter storage at shorter durations.
Because they’re less energy-dense, sodium-ion batteries have a lower risk of thermal runaway, the electrochemical process that can lead to battery fires like the January conflagration that consumed a 300-MW battery array on the central California coast. communities around the country have tightened restrictions on lithium-based energy storage or frozen their development entirely since the fire at the Moss Landing energy facility.
Peak Energy says its time has come
Peak Energy’s Mossburg has a different view. He believes a particular variety of sodium-ion battery can compete at utility scales and that price parity with lithium will come sooner than the skeptics expect.
One big advantage is a 90% reduction in auxiliary power use — a direct benefit of passive cooling. Grid-scale LFP batteries draw significant amounts of power to run the active cooling systems needed to prevent thermal runaway, reducing their cost-effectiveness. Peak says the difference can save operators $1 million or more per year, per GW.
Peak also says its batteries are more durable, degrading 33% more slowly over a projected 20-year lifespan. All told, lifetime costs come in 20% lower than comparable LFP systems, Peak says.