Battery Than Can Produce Utility-Scale Power

Think of an aluminum plant running in reverse, generating electricity instead of consuming it.

That's the concept behind a new stationary battery large enough to produce utility-scale power, a technology being developed by MIT Professor David Sadoway.

The battery produces power by making a sandwich out of 2 layers of liquid metal alloy with a layer of a salt in between, and then placing the entire sandwich in an electrolyte. Ions flow from one metal layer through the electrolyte to the other layer, generating electricity. The whole system is maintained at 700° C.

Sadoway's project has already received a grant of nearly $7 million over 5 years from the Department of Energy's Advanced Research Projects Agency-Energy, or ARPA-E. Soon after that, the French oil company Total announced a $4-million research agreement with MIT to jointly develop a smaller version of the battery.

In its press release announcing the grant for the battery (along with names of other grant recipients), ARPA-E said:

If successful, this battery technology could revolutionize the way electricity is used and produced on the grid...

Batteries to Store Wind Power in California

More news from the energy-storage front. I tell you, this sector is hopping!

The Modesto Bee reports that Primus Power Corp. in Alameda, Calif., recently won a $14 million federal grant to develop batteries that will store 25 megawatts of green electricity. The Modesto, Calif., Irrigation District's wind energy will send juice to the batteries, and the stored energy will be sold during periods of peak demand.

Doing so will displace some of the power generated from natural gas.

The Modesto Irrigation District provides electricity, irrigation and surface water treatment to parts of California's Central Valley. It wants to get 20% of its power from renewable sources by 2017, according to the Bee. The District will take part in a 5-year demonstration of the batteries at no cost to its ratepayers.

California Might Use Compressed Air to Generate Electricity

Wind farms produce more than enough electricity at night -- when demand is lowest. One option for storing the excess energy is to capture the resource that generates it. In effect, to bottle the wind.

Or cram it into caves.

Which is what Pacific Gas & Electricity would like to do. The utility just received a $25 million award from money set aside in stimulus funds for smart-grid projects. The award will help pay for a study to find out if California can pack away pressurized air in underground caverns.

Here's how a compressed-air power plant would work. At night, wind turbines would force air into porous rock in Kern County, Calif. In the morning, the compressed air would be released to rotate turbines, which would generate up to 300 MW of electricity.

The generating plant will cost about $365 million. According to CleanTechnica, building a fossil-fuel plant that supplies the same amount of energy would come to $850 million.

Nanotech Batteries Deliver High Power at High Energy Density

Electrostatic nanocapacitors formed in nanoporous anodic aluminum oxide (darker yellow) film by sequential atomic layer deposition of metal (blue), insulator (yellow), and metal. Insert: cross-section of actual structure, represented as rescaled scanning electron micrograph. (A. James Clark School of Engineering, U-Md.)

Electricity is normally stored in batteries and capacitors. The problem is, these devices have inherent limitations that prevent them from meeting our electricity needs.

They can't deliver the high power, high energy density, and fast recharge that modern electrical usage demands.

Batteries store energy but can't provide high power or fast recharge. You have to connect a lot of batteries to achieve high power.

Electrochemical capacitors can generate high power but have low energy storage density.

And electrostatic capacitors deliver high power and fast recharge, but like their electrochemical counterparts, suffer from low energy storage density.

High power, high density, fast recharge. You need all 3 -- but can only have 2.

Still, all is not lost. Nanotechnology comes to the rescue.

Researchers at the University of Maryland's NanoCenter have built electrostatic nanocapacitors out of billions of nanostructures, increasing the energy storage capacity of the capacitors by a factor of 10 over that of conventional devices.

According to the story in InTech, a publication of the International Society of Automation:

This advance brings electrostatic devices to a performance level competitive with electrochemical capacitors and introduces a new player into the field of candidates for next-generation electrical energy storage.

These nanocapacitors could be mass-produced as energy storage panels layered one on top of the other. Multiple panels could stack together inside a car battery system or solar panel.

Long term, nanotech could give us new energy capture technology that would integrate with storage devices used in manufacturing.

Batteries are Big

I've written about batteries and energy storage a few times on this blog. Batteries are key to ensuring the future of renewable energy. Without reliable high-capacity batteries, wind and solar energy will always be adjuncts to electricity derived from fossil fuels.

It seems Warren Buffet believes in the importance of batteries, too. At his urging, MidAmerican Energy Holdings, a utility holding company that Berkshire Hathaway owns 80% of, recently invested in BYD. BYD is a Chinese company that makes batteries and electric cars.

Not just any batteries. Batteries that can store 2 MW. And if they test well, they could lead to systems that can store 100 to 200 MW.

That's utility scale, and a game-changer.

GE to Invest $100 million in Green Battery Plant

This blog has brought up the significance of electricity storage in at least a couple of posts. In a sign that major market players are taking storage seriously, General Electric announced this week it will invest $100 million in a new battery plant near Albany, N.Y.

The plant will start producing batteries by 2011. At full capacity, it will turn out 10 million cells a year, with a total storage capacity of 900 MWh.

GE has so far invested more than $150 million in battery technology. The first batteries from its new plant will find applications in GE's hybrid locomotives. Long-term, the batteries will be used in the rail, marine, telecommunications and utility industries.

GE believes over the next decade, the advanced battery business could be a $1 billion business.

New Battery Could Solve Household Electrical Storage Problem

What if you got all your household's electricity from a battery?

Thanks to a company in Utah, it could happen.

According to the Department of Energy, Americans in 2007 consumed an average of 936 kWh of electricity per month. Or 31 kWh (kilowatt-hours) per day.

Ceramatec, a subsidiary of CoorsTek (yes, that Coors), has developed a battery about the size of a refrigerator that generates 20-40 kWh of electricity per day.

That is truly a remarkable breakthrough. Batteries with high energy density typically use molten sodium and operate at around 600 degrees C. Aside from being too large to fit into your house, they're not something you want to hang around. Sodium in its normal state is fairly reactive. In its molten form, it's extremely toxic and corrosive.

Ceramatec's battery contains sodium too, but the metal stays in a user-friendly state. It is separated from a sulfur compound by a thin ceramic membrane. The thinner the membrane, the cooler the sodium. This membrane is paper-thin, keeping the sodium at a balmy 90 degrees C.

The company says its battery produces a steady 5 kW of power for 4 hours, or 20 kWh, on one charge. It can take 3,650 discharge/recharge cycles over its lifetime, or 1 cycle per day for 10 years. That's a total power production of 73,000 kWh before you have to buy a new battery.

Each battery will cost about $2000. Which means your cost per kWh is 2.7 cents.

My electricity from the local utility in Connecticut costs 23.3 cents per kWh, including all generation, transmission and distribution costs.

A customer could use clean energy from solar panels or wind turbines to charge her Ceramatec battery. If this energy costs less than 20.6 cents per kWh, the battery puts money in her pocket.

Ceramatec says it is 6 months away from commercializing the battery.

Let's hope the product fulfills its promise. Reliable electricity storage is just the shot in the arm renewable energy needs.

Storing electricity from wind and solar systems

The wind wavers. The sun sets. And the electricity they produce stops flowing.

In small-scale installations, this is not a problem. Batteries provide sufficient backup power, or the system is simply connected to the grid.

But what happens when wind and solar systems start supplying substantial amounts of our nation's electricity? Will today's batteries fill the need for gigawatts of power?

Not without some technology changes. As this story from the Christian Science Monitor explains, conventional lead-acid batteries aren't up to the job. Researchers are turning to newer technologies like sodium-sulfur and lithium-ion to meet our immense storage needs.

Some companies are going beyond these electro-chemical solutions, to technologies like compressed air, flywheels and molten salt that store energy from solar power.

While technology is important, so is size. Some of the batteries being built are as large as a double-decker bus and can accumulate megawatts of energy. (By comparison, the battery in your car supplies a maximum of about 1 kilowatt of power.)

But while some companies are betting on size, others believe salvation lies at the microscopic end of things.

Gary Rubloff, director of the Maryland NanoCenter at the University of Maryland, believes nanoscience is the answer.

Rubloff and his fellow researchers are using nanotechnology to increase the amount of electricity a conventional capacitor can store. "Batteries are too big, too heavy, too expensive," he says. He estimates his team can increase a capacitor's power by a "factor of 40 to a couple hundred."

The technological hurdles to ecomomical renewable energy are getting lower day by day.