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Energy on demand

Energy on demand

A patented power-storing device designed by a team of electrical engineering researchers can harness green energy from multiple sources for use during peak periods, substantially reducing electricity costs.

Babak Fahimi may one day be known as the man who made electricity for businesses and homes an easily managed task.

Think the power equivalent of TiVo.

“We store our music and videos for the time when we need them,” the electrical engineering associate professor says. “Why not do the same thing for electricity?”

Storing adequate amounts of electricity when it’s produced cheaply in non-peak hours or when it could be produced inexpensively by renewable solar or wind sources would take pressure off both the power grid and consumers’ pocketbooks. It also would be useful for crisis moments like the record winter 2010 snowfall that left an estimated 500,000 people in North Texas without electricity, some for days.

Unfortunately, today’s power grid is either on or off. And if it’s off, there’s not much we can do since electricity in useful quantities can’t be stored. Likewise, we can’t easily store energy when it’s being produced cheaply for a time when it becomes more costly.

Or can we?

Babak Fahimi

Babak Fahimi, electrical engineering associate professor

Dr. Fahimi has designed the Intelligent Power Controller (IPC), a patented power-storing device. Essentially, the IPC stores enough energy to run a small business or large home from a few hours to days, depending on how much capacity the customer wants. Though such a computerized smart system would come in handy during blackouts, the idea is to substantially reduce electricity expense all the time.

“One of the problems the power grid faces today is that the cost of production is too high,” Fahimi says. “This is primarily because the production capacity has to be designed to accommodate peak power demand by customers.

“This peak demand changes according to the season, according to the region, and the type of industries that are located in areas. So the system has to be over-designed. That fact results in increased costs in both dollars and environmental impact.”

Some sources of renewable green energy are inconsistent. Solar panels don’t make electricity after the sun sets. Wind generators don’t turn when there’s no wind. Further, power that is produced by some sources does not meet the technical requirements of the utility grid because voltage and frequency can vary.

“You need energy compatible with what is acceptable on the grid,” Fahimi says. “The IPC accepts energy from all kinds of sources, stores it, and converts it into a form compatible with the grid.”

For instance, IPC owners might have solar panels producing power that could be stored to supplement utility power or run a plug-in hybrid or electric auto. They might want to load up with power late at night when the commercial grid is producing lower cost electricity. Down the road the IPC might enable entire communities to provide all of their electric energy with renewable sources.


UT Arlington and Fahimi’s energy laboratory have worked on the technology for more than four years, and Fahimi says commercial marketing could begin by year’s end.

Businesses will likely be the first customers because they typically pay higher electricity charges during peak usage periods. IPCs will let them store energy purchased during off-peak times and use it during peak periods. The devices also are computerized and capable of learning consumption patterns.

A 50-kilowatt IPC—enough to run a 2,000-square-foot house for a day or more—is about the size of a three-drawer file cabinet. Units can be connected to increase storage.

“We’re building a 50-kilowatt in the lab for about $2,000,” Fahimi says. “Once commercial construction begins, IPCs will no doubt become cheaper and cheaper. The ultimate idea is to have a huge energy storage capacity spread in a decentralized way across the marketplace.”

Fahimi sees a time when virtually every home will have a green IPC as standard equipment. He believes the devices will pay for themselves in two years or less.

- O.K. Carter