close this window
The Empowering Power of Ice
Blocks of ice are joining molten salt and compressed air as ways to deliver yesterday’s energy when it’s wanted today.
Just when most of the country has “had it up to here” with ice, a coalition of publicly run electric utilities in Southern California say it has plans to cool the state’s energy problems by making even more.
The Southern California Public Power Authority announced last month it plans to construct a 53 megawatt energy storage project over the next two years to store power — in blocks of ice.
David Walden, energy systems manager for the authority, said on-peak power demand is the one of the biggest problems facing the region’s electric utilities. He told Miller-McCune that power purchased during peak hours is not only “expensive,” but that the generators “typically dispatched within the industry to meet peak demand are the most inefficient units that we have.”
In a press release, the authority said its new project will “permanently reduce California’s peak energy demand by shifting as much as 64 gigawatts of on-peak electrical consumption to off-peak periods.” How? By switching off air conditioners and instead, using thousands of tons of ice to cool commercial space.
The authority plans to deploy an energy storage system called Ice Bear, developed by Windsor, Colo.-based Ice Energy. The units will be distributed among 1,500 rooftop and commercial air conditioners over the authority’s 7,000-square-mile service area. Tied in to normal rooftop air conditioners, Ice Bear units will be used to freeze hundreds of gallons of water nightly, when demand for power, and its price, are lower.
During torrid working hours when air conditioners are the major draw on California’s power grid, Ice Bear switches off air conditioning and circulates the warm air from the building’s interior over special panels chilled by melting ice. The resulting cool air is then pumped through the ventilation system back into the building.
Once the ice is completely melted, which Ice Energy said takes about six hours, the air conditioning system switches back into normal operation and the cycle starts again. By that time, the power authority said, the peak-load period will have passed, resulting in less strain on the power grid and “an overall 8 percent efficiency advantage” for the customer.
Shifting energy generation away from demand has become more common, especially with renewable sources that can’t produce on demand. Solar projects, for example, may use molten salt or compressed air to release the sun’s energy once it’s gone down. Other projects have called for pumping water into upstream reservoirs at night when rates are cheaper, then letting it gush through hydroelectric facilities during peak hours.
Ice Energy, for its part, likens its product to using a battery, but without heavy metals or noxious chemicals.
Much of California’s historical summer electricity shortfalls have occurred on hot days when air conditioners suck up to a third of the state’s electricity and either generation or transmission can’t keep up. Meanwhile, climate change, not surprisingly, is expected to make the pinch worse.
Bill Carnahan, the authority’s executive director, said the project “is a convenient and cost-effective solution for managing peak demand. By using storage to change how — and more importantly when — energy is consumed by air conditioning, we can offset enough peak demand in the region to serve the equivalent of 10,000 homes.”
This isn’t the Ice Energy’s first foray into California, having worked on much smaller scales with the Pacific Gas and Electric Company’s “Shift and Save” program since 2007, and the city of Redding since last summer.
Walden said signing up for the program is relatively simple. “We do all the installation,” he said. Customers need only provide an access agreement similar to that used for any other piece of utility equipment, such as a transformer or meter.
“The system is compatible with 85 percent of existing air conditioning units,” he said. And cooling with ice made overnight consumes less electricity than running air conditioners during the day, “partly because it’s cooler at night, and partly because the small compressors used to make ice are more efficient than the larger compressors used on commercial air conditioners.” He added that air conditioners’ life spans increase because they aren’t on as much.
Walden said the authority has been using the system on its own buildings “for over five years. … There’s a lot of history behind the product showing that it works.”
Sign up for our free e-newsletter.
Are you on Facebook? Become our fan.
Follow us on Twitter.
word on the street
- ACRobbins
more in this section
Why Robot Maids Won’t Do the Dishes
20,000 Robots Under the Sea
San Francisco Bay Model Is Flush With Life
Teens Weigh Ethical Animal Research Dilemmas
Animal Research’s Changing Equation
Feds Put Chimp Experiments in Cage
Scientists Deflated by Obama’s Policy Decisions
Engaging Iran Through Vaccine Diplomacy
Does This Make My Antenna Look Big?
The iPod Touch as a Crop Saver
also by this author
David RichardsonDavid Richardson began his journalism career operating a video news service in Washington, D.C., that covered federal agencies and Congress. His film ...
Among Antibiotics, Resistance Knows No BoundsA microbiologist on the front lines of antibiotic resistance sees a lot of ways to improve the search and development of new antimicrobials.
Building Cities With Sustainability in MindMunicipal waste — from poop to heat — can be a valuable resource that could run our cities more cheaply and sustainably, says a hands-on Canadian ecologist.
Pollinating Local Is the New BuzzAn annual Woodstock for honeybees highlights one of the factors leading to the pollinators’ decline in North America. Perhaps keeping bees at home is the solution.
Teaming with Technology to Fight TB and HIVTuberculosis and HIV are both high-profile global health scourges, but surprisingly little focus has been paid on treating them when they team up.
Balancing the Power of Offshore WindFears that wind only provides power when it’s blowing outside could be neutralized by drawing from a wide area — like the U.S. Atlantic coast.
Receive 1 year (6 issues) of our print magazine for just $14.95. Miller-McCune features polished, in-depth reports on research and solutions across the policy spectrum — from health care, education and energy to international affairs, poverty and the global economy. It's a must read for well-informed and solutions-driven individuals.
follow us on:
join our newsletter:
from the source
A lot of people say they watch the Super Bowl mostly for the ads. But it turns out a good game surrounding those ads makes them seem better.
After decades of obstacles hindering the voting process, new laws will allow overseas and military voters to submit their votes in time for the 2012 election.
World health leaders announce coordinated push to eradicate or control neglected tropical diseases.
A survey of award-winning children’s picture books from 1938 to 2008 suggests our increasing estrangement from the natural environment.
Rather than moaning about too many cars on the road, the Ridesharing Institute says the real key to battling traffic congestion and pollution is filling empty passenger seats.
