The U.S. must first develop unsubsidized, cost-effective energy storage technologies, validate reliability and safety, establish an “equitable” regulatory environment, and boost industry acceptance before it will see the widespread deployment of energy storage systems, says a report released today by the Department of Energy (DOE) to members of the U.S. Senate.
Commissioned by Sen. Ron Wyden, who chairs the Senate Energy and Natural Resources Committee, the 67-page report, “Grid Energy Storage December 2013,” seeks to identify efforts to address each of the four key challenges outlined by the DOE that is says are hampering grid storage.
The DOE notes that the U.S. lags behind Europe and Japan in grid storage development. It has only about 24.6 GW of grid storage (or about 2.3% of total electric production capacity). About 95% of that capacity is pumped storage, and the remainder is from technologies such as compressed air energy storage, thermal energy storage, batteries, and flywheels.
The report also presents a brief overview of a variety of storage technology, including primary applications, what is currently known about developing technologies, and key challenges. It lists electrochemical capacitors and thermochemical energy storage technologies as “currently cost-prohibitive.”
But while it details a number benefits storage could provide, including as a critical component of grid stability and resiliency, the future of energy storage in the U.S. must be “cost competitive (unsubsidized) with other technologies providing similar services,” the DOE says. Also, “energy storage should be recognized for its value in providing multiple benefits simultaneously; and ultimately, storage technology should seamlessly integrate with existing systems and sub-systems leading to its ubiquitous deployment.”
Achievement of cost-competitive energy storage technology will entail requiring attention to factors such as life-cycle cost and performance (round-trip efficiency, energy density, cycle life, and capacity fade), the report suggests. “It is expected that early deployments will be in high value applications, but that long term success requires both cost reduction and the capacity to realize revenue for all grid services storage provides,” it says.
Strategies recommended by the DOE to increase storage technology cost competitiveness include targeting scientific investigation of fundamental materials, transport processes, and phenomena enabling discovery of new or enhanced storage technologies with increased performance. It also calls for materials and systems engineering research to resolve key technology cost and performance challenges.
“Validation of the safety, reliability, and performance of energy storage is essential for user confidence,” it adds, suggesting increased research and development on degradation and failure mechanisms and accelerated life testing. It also calls on the development of standard testing protocols.
Meanwhile, “value propositions for grid storage depend on reducing institutional and regulatory hurdles to levels comparable with those of other grid resources,” the report acknowledges. These could be resolved with collaborative public-private sector characterization and evaluation of grid benefits of storage, exploration of technology-neutral mechanisms for monetizing grid services provided by storage, and development of industry and regulatory agency-accepted standards for siting, grid integration, procurement, and performance evaluation.
Finally, the DOE says “Industry adoption requires that they have confidence storage will deploy as expected, and deliver as predicted and promised.” To boost that, the agency suggests collaborative, co-funded trials and demonstrations to enable experience and evaluation of performance, especially as it applies to facilitate renewable integration.
—Sonal Patel, associate editor (@POWERmagazine, @sonalcpatel)