Utility-ScaleStorage:MovingFrom Trialsto the RealWorld

Any day now or not for a decade, depending on whom you

ask

KATHERINE TWEED: AUGUST 5, 2011

Utility-scale storage is the Holy Grail to many in the industry. Some would

say it is just around the corner, while others argue it is floundering outside

of the realm of commercial viability.

During a recent webinar, Utility-Scale Storage: Determining the Best

Investment Strategy for Utilities, a group of experts tried to tease out the

drivers that are pushing the industry forward, as well as those that are

holding it back.

There were varying opinions about what holds the most promise for

storage on the grid, but there was also a consensus that it was time to

move out of the starting gate and ramp up the real-world learning curve.

“In the past year, a lot of good things have happened,” said Imre Gyuk,

program manger for energy storage research at the U.S. Department of

Energy. He pointed to the deployment of $185 million in stimulus funds for

storage projects and federal and state legislation.

Gyuk also highlighted many of the demonstration projects, from wind

firming in California to community battery storage at American Electric

Power to flywheel projects with New York Independent System Operator, as

examples of technologies making forays into the field.

Storage, of course, is not monolithic. Flywheels, like those erected in New

York by Beacon Power, only store energy for a few moments: the devices

serve to balance power delivery. Batteries -- which sport a chemistry

cookbook that includes lithium ion, sodium, zinc, fiberglass and other

variants -- store energy for intermediate periods. For persistent power

storage, there's a raft of compressed air startups like Bright Energy and

SustainX, as well as energy storage via water and gravity. In general, the

less time you have to store energy, the more market-ready your technology

is at the moment. Further out: ammonia and liquid metals.

The leap out of the lab is significant, but huge challenges remain. The

community storage projects, for example, which could someday make use

of electric vehicle batteries after their useful lifespan inside the car, have

some basic issues. “Are there issues with the transformer and this [battery]

sitting next to each other?” asked Melanie Miller, senior project manager at

Duke Energy. “It’s easy to put storage in a lab setting. You don’t have to

worry about digging up someone’s front yard.”

The logistics of simply finding a suitable site for storage is just one issue.

Duke also has battery storage paired with solar projects to understand how

to most effectively use it for peak shaving and, in a separate project, for

frequency regulation. “We’re trying to pair multiple components to get the

biggest value,” she said.

More bang for your buck will be the secret for storage success in coming

years. While some technologies regulate voltage and others can store

more energy to dispatch at peak, experts agree that solutions that meet the

specific needs of a utility are going to get deployed even if they’re not

completely optimized. For project managers, it’s really important to

understand those hyper-local issues to get the most out of storage,

according to Rahul Walawalkar, vice president of emerging technologies

and markets for customized energy solutions. He also said that round trip

efficiency will be a key issue for any technology.

Others agreed that carefully weighing the different options for specific

applications will be key. “When we talk about benefits, they’re entirely

dependent on the time you operate and where you are,” Haresh Kamath,

strategic program manager for EPRI, said during the webinar, which was

hosted by Smart Grid Today. “If you’re justifying cost on those very variable

targets, you have to be careful.”

Many demonstrations are already underway to better understand how

storage can work best in different applications. The DOE helped fund 16

projects, including a 25 MW/3-hour battery plant for the Modesto, Calif.

Irrigation District to firm 50 MW of wind. At PJM, stimulus funds helped

install a 20MW flywheel storage facility. Pacific Gas & Electric is planning a

300 MW/10-hour compressed air storage facility in Tehachapi, Calif. Unlike

utility projects, which can be viewed as proprietary, storage is likely to

result in a lot of information sharing, as the need for it is already overdue.

AEP Ohio, which is just starting a community energy storage pilot, said that

all of its data from the project will be open source.

Aside from gaining a more complete understanding of how storage will

impact the grid, FERC’s ruling earlier this year about pay for performance

for grid storage, which requires grid operators to pay more for faster-

ramping resources, is also pushing the market towards commercial viability.

Walawalkar is optimistic, betting that there’d be at least a half-dozen

technologies on the market by 2015. Even with changes in the market,

Kamath didn’t expect to see a standardized grid-ready product until after

2015, and maybe closer to 2020. “We need to have something that’s a lot

more than a science project,” he said.

Tags: caes, community energy storage, compressed air energy storage,

energy storage, flywheel, grid storage, storage