The puzzle of how best to store electricity — whether at grid scale or building scale — has huge implications for the future of renewable energy and the smart grid.
It's been about 212 years now since Alessandro Volta demonstrated the first “voltaic pile” — what we know today, in English, as a battery. An electro-chemical device for storing and releasing electrical charge is a wonderfully useful thing. Over the past two centuries, and in particular the past few decades, batteries have become a fundamental source of power for what we consider the modern way of living. They're everywhere — they're in our phones and our toothbrushes and our children's sneakers — but there's a lot of people investing a lot of time and money and brain-sweat in the search for ways to extend the reach of batteries to a whole new level. And it's not just about batteries.
Batteries are just one of many options for addressing the stubborn problem of storing energy on a large scale. Utilities adopting renewable energy, especially wind and solar power, need batteries or some other technology that will allow them to store the output from these intermittent sources so they can maintain power quality and the ability to respond to demand peaks when the wind isn't blowing and the sun isn't shining.
California is a good example. The Golden State's 2020 target of getting 33 percent of its power from renewable energy sources will depend heavily on its ability to solve the puzzle of energy storage. Studies indicate that California may require 3,000 to 4,000MW of fast-acting energy storage by 2020 to integrate the projected increase in renewable energy, says a Nov. 2011 report from the California Energy Commission's Public Interest Energy Research (PIER) Program.
The Federal government is also heavily involved in promoting energy storage technology R&D. In November, the National Electrical Manufacturers Association (NEMA), Rosslyn, Va., which has an Energy Storage Council devoted to the subject, endorsed legislation intended to spur deployment of energy storage technologies. The “Storage Technology for Renewable and Green Energy” (STORAGE) Act of 2011 (S 1845), which is now in committee, is a set of investment tax credits to promote adoption of the spectrum of energy storage technologies, including batteries, flywheels, superconducting magnetic energy storage and other technologies.
“The ability to store energy during times of low demand and deploy it during peak demand reduces costs, improves efficiency, and precludes the need for new electrical generation,” said NEMA President and CEO Evan Gaddis. “By remaining technology-neutral, the STORAGE Act promotes competition in the electroindustry and allows the marketplace to determine which technologies are best suited for any given application.”
The STORAGE Act would offer a 20 percent investment tax credit to energy storage used in connection with the power grid, with no project eligible to receive more than $40 million. To promote efficiency and distributed generation in the commercial and residential markets, the bill offers a 30 percent credit (up to $1 million) for on-site application of energy storage.
The need for energy storage is huge, and the payoff likely will be, too. It's no surprise, then, that research and development efforts to find the best large-scale energy storage solutions have been popular investment choices for venture capital firms lately. A report cited by the Electricity Storage Association (www.electricitystorage.org) — based on analysis by Ernst & Young of data from Dow Jones Venture Source — found that the energy-storage segment led cleantech investment, raising a total of $865.2 million throughout 2011.
Energy storage is not just an issue at grid scale, of course. An increasing number of options are in the market or under development to allow commercial buildings to have their own energy storage systems for backup power, power conditioning and small-scale deployment of renewable energy.
Lithium-ion batteries are one of the hottest areas for energy-storage research because they are the preferred technology for powering small electronics and electric vehicles, but at grid scale, lithium-ion technology has proven more difficult as larger versions are expensive, prone to overheating, and susceptible to electrical shorting. Research is attacking all these fronts and pilot projects are underway.
Battery developer and manufacturer A123, Waltham, Mass., is engaged in some large-scale deployments of its “Nanophosphate” lithium ion systems, such as two it announced last month — one in Hawaii and another in New England.
A123 agreed to supply its grid battery system (GBS) to Maui Electric Co. (MECO), which serves residents and businesses on the islands of Maui, Lanai and Molokai. The system will be installed at the utility's Wailea substation on Maui designed to deliver one-megawatt (1MW) of power for a full hour to reduce the peak energy load on one of the substation's transformers, which is expected to increase grid stability and improve power quality to help MECO meet the objectives of the Maui Smart Grid Project .
The GBS turnkey storage system is expected to help MECO meet the objectives of its smart grid project, which include reducing distribution circuit peak load, minimizing emissions, enabling greater utilization of renewable energy sources and improving power quality and grid stability. The A123 system will provide a number of services in addition to peak-load shifting, including regulating voltage fluctuation, reactive power (VAR) support and relieving wind curtailment.
A123 also announced a deal in December with investor-owned electric and gas utility NSTAR, which serves 1.4 million customers in central and eastern Massachusetts, to connect one of its 2MW GBS systems to the power grid at NSTAR's substation in Medway, Mass. It will be owned and operated by A123, and will be designed to provide area regulation services, which are used to address momentary differences between electric power supply and demand. The pilot project is expected to allow A123 to learn more about how its GBS performs in real-world applications in order to facilitate further product improvements designed to reduce total cost of ownership.
The use of energy storage technologies at the scale of a building, campus or neighborhood opens the way for more distributed approaches to grid balancing and presents more realistic opportunities for electrical distributors to take part in growing and serving this market. A study released in November by cleantech market research firm Pike Research found that the market for energy storage in commercial buildings is poised for significant growth in the years ahead. In 2016, the firm forecasts, total revenue from energy storage systems will reach at least $4.9 billion. Under a more aggressive, high-growth scenario, total energy storage revenue for commercial buildings could reach $6.7 billion, the firm said.
Today the main energy storage applications in commercial buildings are backup power — where the major players are Eaton Corp., Schneider Electric and Emerson Electric — and time shifting using thermal energy storage (TES). These will continue to lead the market in the foreseeable future, Pike Research said, but added that significant opportunity also exists for commercial buildings to utilize flow batteries and lithium-ion batteries for energy storage as the economics of those technologies continue to improve.
According to the report, “The total potential value of various benefits to building occupants of energy storage — in terms of reliability of electricity, power quality, firming the capacity of renewables, and so on — could reach the $150 billion range over the next decade, although the actual value of the market will likely be smaller than the potential.”