Energy Storage Technology at Renewable Market’s Edge

A host of new technology developments in energy storage are at the edge of the massive commercial market for solutions to renewable energy intermittency. While storage prices must continue to drop prior to mainstream adoption, there are a few substantial niche markets where storage already makes overwhelming sense. While high performance batteries today can cost between $700 and $800 per kilowatt hour (kWh), and lower performance batteries cost between $400 and $500/kWh, prices are headed downward drastically for those battery companies that survive, several sources at the Renewable Energy Storage Symposium said in San Diego last week.

Microgrids a Natural Energy Storage Host

The rising development of microgrids is the single greatest factor that will drive the energy storage industry, suggests Christopher Kuhl, the team leader for global sales at ZBB Energy Corp., in Menomonee Falls, WI., one speaker at the symposium. “The microgrid is the next step in the value chain of renewables and energy storage. Unfortunately it has taken a couple of disasters to show people what they are worth,” he says. Following the grid outages caused by Hurricane Sandy, several communities and states in New England are developing microgrids for emergency planning. “Connecticut alone is investing $30 million in microgrids now,” he points out. Such emergency planning projects will not be as sensitive to battery cost reduction as more commercial clients, and thus are a strong niche for early adoption. 

Reducing Battery Price Key to Growth

One innovative battery maker, Ionex Advanced Energy Storage Systems, of Long Beach, is developing a battery based on a silicon and graphene anode, that will discharge “faster than any other battery on the market,” says Phillip Roberts, the company CEO, also spoke at the symposium. Utilizing technology originally developed at Argonne National Laboratory, Ionex is currently working with global battery manufacturers, targeting a price of $350 per kilowatt hour for its batteries. “We hope to get down to $150/kwh over the next 18 months or two years, with a 5,000-cycle lifetime,” he says.

Pricing will make or break some battery makers over the next year or two, others suggest. “This is a year of shakeout after all the DOE money that was spread around last year; some of those participating companies aren’t in business any longer,” points out Lee Kosla, the sales manager for energy storage at French lithium-ion battery company Saft America, in Larkspur, Calif. Kosla spoke at the symposium. Saft batteries were incorporated into German residential PV solutions by Bosch earlier this month.

Cutting Spikes Off Time of Day Use

Valerio De Angelis, the vice president of grid storage systems at Urban Electric Power, based in New York, points out the clear need for peak energy shaving in cities with time of use charges like New York, Los Angeles and other urban centers. Speaking at the symposium, he described his company’s commercialization of an innovative Ni-Zn flow-assisted 100-kW battery system. Supported by a grant from City University of New York, his company is commercializing research done at the school. Their power battery can discharge 85 percent in 30 minutes, or 100 percent over 4 hours; the life of the battery is 10 years, compared with a lead acid battery that would fail after 250 cycles or so.

“Our building consumes 1 MW, and by chopping 15 minutes of peak use time, we can amortize the cost of our energy storage system in three years,” De Angelis says. The project is expected to begin operating by the end of August pending fire safety inspection. “ConEdison sees the use of building-based energy storage as a way to shave peak use in the future rather than bringing more power into the system, which is already maxed out in terms of infrastructure,” he notes.

Urban Electric Power also has developed a Zn-MnO2 energy battery that can be used for industrial applications where the use peak is flatter than commercial use spikes,” De Angelis says. “This battery is available for $70/kwh but the operating cost works out to a few cents per kW cycle — that’s cheaper than you can buy a car battery,” he says.

Robust Operating System Software Needed

The need for robust energy storage operating systems becomes more apparent as the number of disparate assets in the total energy system increases. One energy storage developer offering a sophisticated computational approach is Greensmith Energy Management Systems, of Sterling, VA. “The operating system question is not how to optimize just a few renewable systems but hundreds or thousands of systems,” says John Jung the CEO of Greensmith, also a speaker at the symposium. His young company has sold over 20 systems since 2011, ranging from 50 kW to multi-MW capability, he says.

“Energy storage systems have the capability of being a very flexible appliance that does multiple things simultaneously,” Jung says. “Most clients are past crawling in terms of energy storage data usage, and are walking now, but we want them to run,” he says. His control system includes multi-relational databases that help predict site-specific usage after accumulating three months of data. “You start out small, study the overall system behavior, and then size the energy storage appropriately,” he says.

While the company assembles the best-of-breed battery and inverter components for its modular systems, it has worked with six different battery chemistries. Although the energy storage systems Greensmith has shipped to date have typically included only one type of battery thus far. “But we envision that in the near future we will have multiple types of battery systems in our modules,” Jung says. Pairing so-called “power” batteries, which can discharge in a matter of minutes, with so-called “energy” batteries, which discharge at a lower rate over a period of hours, will add flexibility to the functions the energy storage system can provide, improving ROI, he says.

Greensmith has installed systems on islands, in microgrids like buildings or campuses, and at utility sites. One recent installation was a 1.5-MW unit for San Diego Gas & Electric that was tasked with optimizing the intermittency of a photovoltaic installation. Among the many functions that a basic energy storage system can offer, Jung says, are: load following; renewable ramp rate; solar PV following; EV charge stations; frequency regulation; voltage and VAR control; energy arbitrage; peak shaving; time of use optimization; demand charge rate management; grid islanding, backup power and microgrid management; and calibration and battery maintenance. “You still have to cherry pick the environment and get an ROI from various value streams,” Jung suggests.

Among clients, Jung estimates that 70 percent are on the customer side of the utility meter. Of that figure, about 40 percent are independent power producers, he notes. Renewable energy generation curtailment by the utilities is one factor driving that new client set, he notes.

Read more energy storage news here.

Lead image: Train tracks via Shutterstock

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Charles W. Thurston is a journalist who specializes in renewable energy, from finance to technological processes. He has been active in the industry for over 25 years, living and working in locations ranging from Brazil to Papua New Guinea.

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