Troy McBride was soaking up the sun at Elizabethtown College's "solar cabin" last week and talking about the weak link in renewable energy systems:
Troy McBride talks about alternative energy inside the
solar house at Elizabethtown College.
Solar panels trap the sun's energy atop the solar house at Elizabehtown College and stockpiles it on a
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The battery.
A lot of systems use ordinary lead-acid units to absorb energy generated through solar panels or wind turbines. The batteries then provide power when the sky is dark or the air still.
But you have to frequently recharge or replace batteries, said McBride, an Elizabethtown assistant professor of physics and engineering.
In developing countries, noted Bill Ayres, an Elizabethtown professor of political science, batteries are expensive. People steal them.
Thus the experimental solar cabin perched on the east end of campus.
McBride and his students are developing new-school energy storage systems there. And in Project uGesi, a multidisciplinary initiative with Ayres, they're planning to soon export a solar-powered prototype to a Zulu village in South Africa.
The goal of the new village center: providing isolated farmers with a durable (more than 30 years), stand-alone, low-maintenance power source.
The energy generated at the center could be used to power lights and refrigerators, drive pumps, recharge cell-phone batteries and even run computers to access the Internet.
After that, said Ayres, who heads Elizabethtown's Center for Global Citizenship, who knows?
Any new technology must be competitive if it is to flower, Ayres said.
On the plus side, he added, "this can be done anywhere. If you think globally, there are a lot of places where this system would make sense."
Power to the peopleThe 200-square-foot cabin built by student power over the past two years showcases a conventional self-contained solar energy loop.
Last Thursday, rooftop panels caught the morning rays. Light played through south-facing windows and bounced off knotty-pine walls. Two 12-volt car batteries stockpiled the power from the sun.
But the future might belong to newer storage technology.
Scientific American spotlighted the trend last month in an article about converting solar energy to compressed air.
The topic is hot at Elizabethtown, where McBride will soon be occupying The High Laboratory for Engineering Research, a dedicated work space funded by a $50,000 grant from The High Foundation of Lancaster.
Besides a solar cabin, a solar boat and Project uGesi, McBride and his students are pursuing a hydrogen-fuel secondary-energy storage system as part of a U.S. Environmental Protection Agency contest.
At the core of uGesi — a Zulu term for "power to the people" — is an air-compression system that would hoard renewable power using hydraulic and pneumatic motors.
The fundamentals are well-known, explained McBride, who said he developed a passion for renewable energy research while at Dartmouth College.
A wind- or solar-powered electric motor forces hydraulic fluid into an accumulator. The apparatus pipes air into a tank and then releases it at a convenient time to drive a turbine.
But the captured energy diminishes with each step.
Creating a super-efficient system is the key, said McBride, who is using off-the-shelf components from two of the project's corporate sponsors, Rexroth Bosch Group and Airline.
The professor said he's eagerly waiting to see how the Elizabethtown-designed technology will perform.
So, presumably, is nKosi Thokozile, chief of the Project uGesi host settlement in the KwaZulu-Natal region, some seven hours southeast of Johannesburg by car.
The Elizabethtown team chose to build in South Africa because Ayres had connections there through a previous academic post at the University of Indianapolis.
When he heard about McBride's plans for a demonstration unit, Ayres recalled, "I said why build it in the United States? Why not go somewhere that has a ton of sunshine" and a faltering electrical grid?
The project, which McBride estimates will cost about $100,000, is being financed mostly with private-sector donations from contributors in South Africa and this country, including Elizabethtown College.
Ayres said that Bruce Alan Johnson Associates of South Africa is helping Elizabethtown forge connections there.
The community encompasses a couple of thousand widely scattered Zulus farming rolling hills reminiscent of Vermont, added Ayres, who first visited the site with McBride last March.
The physics professor has designed a village center in the form of three attached cinder-block rondavals, which are round African huts with conical, thatched roofs.
Three photovoltaic solar panels mounted on posts will rise in front of the center.
McBride said the installation will cover 2,000 square feet and generate about the same amount of energy consumed by a small house in the United States.
He and Ayres are planning to return to the village with students to frame the building this spring.
"As far as I know," McBride said, "it's the first [compressed air storage] application outside the laboratory."
He and Ayres emphasized that the center is a development project in which the South Africans will take an active role.
This kind of project "can't survive on altruism and good feeling," Ayres said.
The future of the technology is uncertain in a market in which solar and wind, though mushrooming, still total less than 2 percent of the energy mix.
"Making a dent is going to take a while" in the United States, McBride said.
Still, he added, the need for energy-storage solutions is growing along with intermittent generating sources such as wind and solar.
If it takes off, Project uGesi could become a model for many such stations.
At the least, Ayres said, it will kindle a new light — and a new way of life — in one African community.
"The leaders of that area understand the power of that. So they are very, very excited."
Jon Rutter is a staff writer for the Sunday News. His e-mail address is jrutter@lnpnews.com.
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