Sunrise brief: The future of long-duration energy storage looks bright, but costs need to fall…a lot


Researchers from MIT and Princeton University took a deep dive into the role of long-duration energy storage (LDES) technologies in transforming energy systems. They found that innovative and low-cost LDES technologies could have a big impact, potentially making a deeply decarbonized electricity system more affordable and reliable.

The team defined LDES as a range of emerging technologies that can respond to the variable output of renewables, discharging electrons for days and even weeks and providing resilience to the electric grid.

In their paper, published in Nature Energy, the researchers looked at whether LDES paired with renewable energy sources and short-duration energy storage options like lithium-ion batteries could power a big and cost-effective move to a decarbonized grid. They also looked at whether LDES might end the need for low-carbon energy sources such as nuclear power and natural gas fitted with carbon capture and sequestration.

The researchers surveyed technologies including pumped hydropower storage, vanadium redox flow batteries, aqueous sulfur flow batteries, and firebrick resistance-heated thermal storage, among others.

Key takeaways included:

  • LDES technologies can offer more than a 10% reduction in the costs of deeply decarbonized electricity systems if the storage energy capacity cost remains below $20/kWh. The value could rise to 40% if energy capacity cost of future technologies is reduced to $1/kWh. The current storage energy capacity cost of batteries is around $200/kWh.
  • LDES energy capacity cost must fall below $10/kWh to replace nuclear power; for LDES to replace all firm power options, the cost must fall below $1/kWh.

The researchers said that niche market opportunities for LDES exist now, such as in places with a lot of solar and wind already deployed and where transmission limits exist. In those places, storage could fill up when transmission is at its limit then export power later while maximizing use of the power line capacity.

Virtual Solar Decathlon

The U.S. Department of Energy’s Solar Decathlon is slated to open on April 12 as a virtual event with competing homes “located” on the National Mall in Washington, D.C., where the first event was launched in 2002.

Due to the Covid-19 pandemic, the scheduled 2020 event was postponed and moved to a format in which teams build their homes in their local communities where they will remain after the competition. Future Solar Decathlons will follow this local-build model, with the next competition scheduled for 2023.

For this year’s event, 63 finalist teams were selected, representing 57 collegiate institutions. They will compete in one of seven Divisions: Suburban Single-Family Housing, Urban Single-Family Housing, Attached Housing, Mixed-Use Multifamily Building, Elementary School, Office Building, and Retail Building. In addition to U.S. institutions, college teams from Canada, the U.K., India, Egypt, South Africa, Tunisia, South Korea, and Australia will take part.

Massachusetts has a climate law

Massachusetts Gov. Charlie Baker signed a climate bill into law. After accepting Baker’s “more technical” amendments, the state legislature sent the bill to him a third and final time in mid-March.

The law aims to cut state emissions by 2030 and reach net-zero emissions by 2050. It includes renewables goals, environmental justice provisions, and tax certainty for solar projects. Although solar and environmental groups applauded the law, they called for more action on climate policy.

Nextracker books Spanish order

California-based Nextracker was selected by Solaria Energía y Medio Ambiente to supply 125 MW of solar tracker technology for multiple project sites in Spain.

The company will supply its single-axis NX Horizon product. Solaria based its decision in part on Nextracker’s wind design expertise, which should benefit locations with persistent wind forces due to Spain’s cierzo wind phenomena, which occurs mostly in the autumn and winter and is known for its strong, persistent winds.

Associate Editor Joe Bebon contributed to this brief.

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