Energy storage: drivers and goals
EPRI and dozens of utilities focused on applications
I recently spoke at some length with Dan Rastler, the director of energy storage and distributed energy resources at the Electric Power Research Institute (EPRI). We touched on his newly released study, "Electricity Energy Storage Technology Options," in Monday's cleverly titled column, "Energy Storage Research Just Published."
EPRI, of course, produces primary research for its electric utility sponsors. And industry drivers for storage make it a hot topic, even if some of the technologies involved and the business cases for them remain somewhat nascent.
Rastler recited EPRI's storage mission statement—"Enable a portfolio of storage options by 2015 that are 'grid ready,' safe, reliable and cost-effective"—and expressed confidence that the efforts are on track. He emphasized that EPRI focused on near-term results, which he defined as one to three years.
"Storage isn't a silver bullet for everything, so we need to figure out where storage can make the most valuable contribution," Rastler told me.
That comment echoed remarks made last week to the California Energy Commission (CEC) by Southern California Edison's Mark Irwin, SCE's director of technology advancement. Irwin told the CEC that "storage may provide the means to solve particular challenges, but is not an end in itself. Identifying where and how storage may be used on the electric system (i.e., applications) is a logical and ideal starting point for discussions about it."
This is the thinking that produces the mantra that storage can only be thought of in terms of its application, which then leads to technology choices and the development of business cases that must precede actual investments.
According to Rastler, industry drivers for storage include:
- higher renewable portfolio standards (RPSs) at the state level
- increasing distributed solar photovoltaics (PV) at the distribution system level
- the need to defer capital investments in distribution systems to meet peak load
These drivers are motivating the roughly three dozen utilities that sponsor EPRI's storage research program, which seeks to identify the functional and technical requirements for storage applications that solve a problem.
Technical requirements, of course, must go hand-in-hand with the value proposition and business case. Thus EPRI and its sponsors are analyzing capital costs in an effort to reduce them and developing analytics that the support a business case for prudent investments and, thus, cost recovery, particularly for investor-owned utilities.
By communicating utilities' technical requirements and specifications to vendors, EPRI assists suppliers in meeting the market's needs, which should result in lowered costs through economies of scale once standardized products reach the manufacturing stage.
Among the technologies getting a close look are compressed air energy storage, or CAES, for large-scale wind penetration, a wide variety of battery technologies, as well as storage systems at the substation, community and home levels.
"It's all about understanding value and quantifying benefits," Rastler said.
Thus, EPRI is working on analytical tools for utilities. Among the factors considered in assessing the relative merit of storage options: capital cost, round-trip efficiency and operations and maintenance costs.
While various parties work diligently on analyzing the complexities of the cost-value gap and beneficial business cases, that cannot replace real-world experience with actual equipment. Beyond pumped hydro power, there is relatively little data on the robustness and long-term field operating issues related to various solutions, according to Rastler.
"By 2015 we should have better information on what works well," Rastler concluded. "And we'll have updated information on costs that, hopefully, will lead to more standard products for certain applications."
Intelligent Utility Daily