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Photograph by Skye Dunlap

Garth Lynch installs the inverter which converts the DC sunlight energy into AC current that powers Johnson's home.

Circuit Soleil

New silicon-made semiconductors could give solar power an energy boost

By Justin Berton

People who drive by Suzanne Johnson's Sunnyvale home stop their cars in front of her house.

They get out, march up the front steps, knock on her door and ask her, "What is that on your roof?"

This being July, it sure isn't Santa Claus.

On her roof are six panels that resemble large sheets of black glass.

Inside those sheets is a new solar technology that will fully power Johnson's home using only sunlight.

Not only is she using the energy collected by sunlight, she is also storing the energy she doesn't use.

Once her storage batteries fill up, the excess energy will go back into the area's power grid, owned by the Pacific Gas & Electric Co.

If Johnson sends more energy to PG&E than she uses, her meter will spin backward.

In other words, according to PG&E senior tariff analyst Keith Forsman, the eye-catching black sheets on Johnson's roof could make her the first homeowner in the state of California to actually collect a monthly check from PG&E.

"That is certainly a possibility," Forsman conceded. "But in the end, she should use just as much as she gives, so we should break even."

As for Johnson, an Internet consultant, she's amazed the black sheets have caused such a reaction.

"I got the feeling not a lot of other people were doing this," she said, as workman put the finishing touches on the project last week.

Johnson is just one of eight people in the Bay Area to power their homes using new silicon-made semiconductors.

There are 70 units similar to Johnson's in all of California.

Though Johnson's energy unit is currently a novelty in Sunnyvale, the move to promote solar energy on a national level has gathered unprecedented momentum in the last year.

In June 1997, President Clinton announced a goal to help put solar panels on top of a million homes by the year 2010.

Under project Team Up, the Department of Energy began doling out multimillion-dollar grants to manufacturers of solar-energy products in hopes of dropping consumer costs to a reasonable price.

According to a White House press release issued in April, the goal of one million homes has already been halved just one year after the grant-issuing began.

And, just two months ago, General Motors Acceptance Corporation became the first major fossil fuel-dependent company to start financing solar energy companies.

Jeff Oldham, a special projects manager for Real Goods, the solar company that provided the panels for Johnson's unit, said the action by GMAC, coupled with the current administration's solar friendliness, has those in the industry applauding these efforts.

"If we could just shift the support we give fossil fuels to photo voltaic energy, then we'll be able to see solar panels on every roof top," Oldham said.

In October, the first March for Peaceful Energy will take place in Washington, D.C. The march is being organized by a student from the University of Maryland at College Park. According to their Web site, the marchers hope to "demonstrate renewable and alternative technologies in the attempt to help improve the global environment and economy for the long term, as well as help put an end to oil-related disputes."

For Johnson, she sees her choice to power her house by the sun not only as a sound economic decision (the panels will pay for themselves, hopefully within 10 years) but also as an environmentally conscious one.

"I really do believe this is tremendous for the environment and an underutilized source of energy. I hope to see it more common in the United States," she said.

The nuts and bolts of Johnson's unit are quite simple: The panels will convert sunlight into energy using a semiconductor made from silicon.

The energy travels through conduits from the panels into a box located on the side of Johnson's home.

Half the box works as an inverter, changing the DC sunlight energy into AC current that powers her home and appliances.

The other half of the box is where the storage batteries are located. Another conduit runs from the box to the neighborhood grid, allowing Johnson to send excess energy to PG&E.

Previously, cumbersome panels without the silicon semiconductors were limited to heating water units such as swimming pools. The semiconductor panels, Oldham said, can withstand hail the size of golf balls coming down at 60 mph.

"This is a very durable product," Oldham said. The life span of the panels is about 60 years, he added.

Thanks to the state and federal incentives, the costs for solar energy are dropping.

For Johnson's unit, the cost began at $16,700. But with state and federal rebates, Johnson's out-of-pocket cost will be closer to $11,300.

Forsman estimated it will take Johnson a decade to break even on her unit, where before the technology of semiconductor panels along with government incentives, it took at least 25 years.

"The average resident pays 2 or 3 cents a kilowatt hour," Forsman said. "But she is paying about 11 cents a kilowatt hour, which means that's how much PG&E could be paying her back. This is a really good deal for people taking advantage of this."

Besides the one-time high cost for installing solar energy panels, which could deter potential clients, there are other drawbacks to living under an independent energy unit.

Lightning and other extreme natural elements could wipe out the power supply to Johnson's house in a matter of seconds. Also, a prolonged string of cloudy days and dirty panels could affect Johnson's power source.

Still, Johnson doesn't fear the worst. More likely, she said, when her neighbors are wandering in the dark because of a PG&E power failure, she'll be the only house on the block with all lights on.

If she did lose power for any reason, her storage batteries could last at least one day and possibly more.

As far as answering the door to answer questions for passersby, Johnson said she will happily continue to do so. She added that collecting sun for energy in Sunnyvale is certainly apropos.

"After all, we do live in Sunnyvale, and 'sun' is in the name," she said.

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This article appeared in the Sunnyvale Sun, July 29, 1998.
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