Energy storage has become one of the hottest topics in the electric power industry today as penetration levels of variable energy resources (e.g. wind, solar) rise rapidly. However, from the perspective of the electricity industry, analyzing energy storage can be dauntingly complex, and financial incentives are weakened by depressed electricity prices.
A recent study summarizing the state of energy storage, “Energy Storage and Opportunities: A West Coast Perspective White Paper,” offers the following conclusions:
- Complexities in calculating and realizing the value of energy storage provides multiple system benefits that are often not fully valued, partly because of the complexity involved.
- Energy storage includes both mature technologies and others that appear to have much development potential.
- Energy storage deserves to be evaluated on a par with other resources in utility resource plans.
- Barriers to energy storage development suggest that policy intervention is warranted to promote competition among projects and technologies.
- Standardized integration with utility system energy management systems may be lagging and merits development.
A special challenge for systems operating with more than about 70% variable energy resources is the need for economical energy storage over weeks and months. A promising technology is being demonstrated in Germany, where Audi’s new utility-scale power-to-gas facility produces hydrogen and synthetic methane from renewable energy, water and carbon dioxide. Renewable-sourced methane could allow leveraging existing natural gas storage and generation infrastructure.
Given that the need for longer-term (weeks to months) energy storage may be two or three decades away, what is the appropriate role for the US in developing these technologies today? Should we be content to let other countries lead the way?