What are the most cost-effective innovations for reducing the cost of long-duration energy storage

The most cost-effective innovations for reducing the cost of long-duration energy storage (LDES) focus primarily on advancing several key technologies to bring their levelized cost of storage (LCOS) closer to or below the U.S. Department of Energy’s (DOE) target of $0.05/kWh by 2030. According to recent DOE assessments and reports, the following innovations and technologies stand out for their potential to dramatically lower costs:

Key Cost-Effective Innovations and Technologies

1. Sodium-ion and Lead-acid Batteries
   • Sodium-ion batteries and lead-acid batteries hold the greatest potential for cost reductions among battery technologies, with projected cost decreases of roughly $0.31/kWh LCOS. These technologies are more mature and can leverage incremental innovation to reduce material and manufacturing costs.
   • Lead-acid batteries can benefit from enhancements in cycle life and depth of discharge to extend longevity and efficiency at lower capital costs.
2. Pumped Hydropower, Compressed Air Energy Storage (CAES), and Flow Batteries
   • Pumped hydropower and compressed air storage technologies have strong scalability and are expected to achieve LCOS below $0.05/kWh by 2030 with targeted innovation. These are physical storage technologies that benefit from improvements in site engineering, materials, and efficiency.
   • Flow batteries, particularly vanadium redox flow batteries (VRFBs), stand out because of their scalability, safety, longevity, and environmental benefits. VRFB innovations focusing on reducing electrolyte costs and improving energy density can reduce overall costs significantly.
3. Electrochemical Double Layer Capacitors and Zinc Batteries
   • These technologies also show potential for cost reduction in the range of $0.11/kWh LCOS. Innovations here include materials science advancements to improve energy density and cycle life, which can enhance cost-effectiveness over the long term.
4. Above and Below Ground Hydrogen Storage
   • Hydrogen storage solutions have wide-ranging cost reduction potential due to ongoing innovations in electrolyzers, storage methods, and fuel cells. The range of cost reduction estimates is large, indicating significant untapped potential if technology breakthroughs can be achieved.

Innovation Strategies to Achieve Cost Targets

• DOE’s Long Duration Storage Shot initiative highlights the need for integrated portfolios of innovation, addressing materials, manufacturing, system design, and operational efficiency to drive costs down across these technologies.
• Cost reductions arise from:
  • Improved materials reducing raw material costs.
  • Enhanced energy density and cycle life extending system durability.
  • Scalability allowing economies of scale.
  • System integration optimizing performance and reducing balance-of-plant costs.

Broader Impact of LDES Innovations

• LDES technologies not only help reduce costs but also enable deeper integration of renewable energy sources into the grid, increasing grid resilience and reliability.
• Cost-effective LDES supports clean energy transitions by making 24/7 renewable power more affordable and accessible, avoiding reliance on fossil fuels.

Summary Table of Most Cost-Effective Innovations

In conclusion, the most cost-effective innovations for reducing long-duration energy storage costs involve a combination of advanced battery chemistries like sodium-ion and lead-acid, physical storage methods such as pumped hydropower and compressed air, and scalable electrochemical storage like flow batteries. Achieving DOE’s aggressive $0.05/kWh target by 2030 requires continued focused R&D, deployment scale-up, and integration improvements across these technologies.