SUNRISE FOR SOLAR ENERGY Recent advances may make systems more popular


Sun power makes sense right now for Sam Droege. That's because Baltimore Gas and Electric Co. wants nearly $10,000 to hook up his Davidsonville log cabin home to the nearest electric power pole, a half-mile away.

Mr. Droege's answer was to spend $9,000 on a solar electric system, avoiding the utility altogether. Mr. Droege's 26-foot-by-26-foot home won't feature an electric stove or heater, but it will have a few of the gizmos of modern society, including a washing machine.

Still, it will take a cheaper solar system than that to convert the rest of us to solar. And that's exactly what a number of big-name players are working on.

Power from "the grid," as solar advocates refer to electric utilities, now costs between 5 cents and 12 cents per kilowatt hour -- 8.35 cents in the mid-Atlantic states. The current cost for solar electric power is in the neighborhood of 25 cents to 35 cents per kilowatt hour.

But solar cell research is proceeding at a brisk pace. Within a decade, industry experts say, technological breakthroughs should lower the price of solar power to half of today's levels, making solar cheap enough to entice some suburban homeowners who are "on the grid."

Photovoltaic power, or PV, "is definitely going to get big," says Jack Stone, who is in charge of PV research at the National Renewable Energy Laboratories in Golden, Colo.

Already, he says, solar can compete head-on with diesel generation in remote areas, because it is more reliable and because operating and maintenance costs are much less. Solar is being used to power portable street signs, billboard lights -- even some Baltimore stoplights.

The "next step," he said, is the U.S. residential market. That's going to be a big step. Only 20,000 to 30,000 U.S. homes use PV as their main source of power, according to Home Power magazine, whose husband-and-wife editing team surveys subscribers from their own remote home near Hornbrook, Calif.

The worldwide solar industry attracted interest -- and millions of dollars in investment -- during the oil embargo of the 1970s. The end of tax credits for solar power put a damper on sales in the mid-'80s, and the industry has yet to live up to its promise.

But the industry has been quietly improving the way it makes solar modules, and the modules' efficiency. And technological improvements are expected to drive down costs dramatically.

"There are about 60 companies worldwide who are in a race to pick the right technology and develop low-cost manufacturing," says Bill Howley, chief of staff at the largest PV module maker in the world, Siemens Solar Industries of Camarillo, Calif.

Siemens, part of the West German industrial giant Siemens A.G., is working hard to stay ahead of challenger Solarex Corp. of Rockville, which is backed by U.S. oil giant Amoco Inc.

The basis for solar electric power is the photovoltaic effect, first discovered in 1839 by a French scientist, Edmund Becquerel. PV cells employing this principle have been used for more than a quarter of a century to power satellites.

A silicon solar cell is actually a sandwich of two types of specially prepared silicon, a positive type in back and a negative type in front.

The science

When sunlight hits the cell, it excites electrons in the positive region. Some travel through the junction with the negative material and get trapped there, creating a voltage difference between the back and front of the sandwich. If you connect the negative and positive regions through an electrical load such as a light bulb, electrons will flow through and generate electricity. This is a continuous process, because the sunlight continues to make electrons move.

Today, 90 percent or more of the solar modules being sold are made from solid chunks of the highest-quality silicon. Siemens grows its own crystals in tanks, while No. 2 Solarex Corp. buys high-grade silicon scrap and melts it into bricks at its main plant in Frederick.

Either way, making the solar module is a time-consuming process that requires slicing the silicon into thin wafers, making individual cells out of the wafers, and piecing the cells together into 2-foot-by-4-foot panels with glass covers.

Both Siemens and Solarex are beginning to sell a new type of module called "thin film," made by spraying solar electric material onto a glass plate in much the same way that one would apply a spray tint.

There are trade-offs, though. While the crystal-built modules cost more to make, they are much more efficient, converting 11 percent or more of the sunlight that hits them into electricity. The thin films currently are only 5 percent efficient.

Both companies are working to push up those percentages. Solarex Chairman and Chief Executive John Corsi believes his company can increase thin film's efficiency in two giant steps -- to 10 percent and eventually to 18 percent.

The dark horse in the race is Texas Instruments, which has a joint venture with Southern California Edison to develop solar technology.

TI announced in April that it had come up with a new way to make solar panels using cheaper-quality silicon. TI melts the silicon into BB-size pellets, purifying them in the process. These are bonded to a sheet of heavy aluminum foil that has squares etched into it to hold each pellet.

Like thin film, the TI process lends itself much more to automation than do the crystal approaches. While TI will be selling its first panels within a year, the company is three years away from having a large-scale production plant and the cheap prices that such a plant would allow.

Starting from the premise that a system like Mr. Droege's produces power that costs 25 cents to 30 cents per kilowatt hour, TI believes "that we can get that down by about half," said Eric Graf, marketing manager for TI's photovoltaic program.

He assumes that, along with cheaper panels, there will be corresponding price drops in the other equipment needed, such as batteries and the device that converts power to alternating current, called an inverter.

Other experts agree that costs can come down, and some are even more optimistic than TI.

"You're going to have to get down to $2,500 to $3,000 for the total system," said Bob Kauffman, president of Photocomm Inc., a large solar distributor and installer based in Scottsdale, Ariz. "That's with today's electricity cost."

He points out that the solar industry may get a free ride from a large-scale research project now being undertaken by the U.S. automotive industry. The nation's big carmakers, with government blessings, have formed a consortium to improve battery performance so that electric cars will become more practical.

"What they're trying to do is exactly what we need for the PV industry," said Mr. Kauffman. He added, "There's no way in hell this industry can invest that kind of money."

The United States Advanced Battery Consortium, which was started early this year, will spend in excess of $200 million through 1994, according to Beryl Goldsweig, a Ford spokeswoman. Half the money comes from carmakers, the other half from the federal government.

Moving to the next stage

A melange of remote-power applications has helped the major manufacturers of the panels to stay in business and gradually expand, but it's still only a half-billion-dollar a year industry.

"A number of the companies are just beginning to break even around the world," said Bob Johnson, vice president of Strategies Unlimited, a research firm in Mountainview, Calif., that monitors the industry.

"They are saying to their parents, 'It's time to move into the next stage of mass production.' . . . As that occurs, there is going to be a resumption of competition, and prices will move."

Both Solarex and Siemens are expanding, but they need bigger orders to make the leap to large-scale production.

Ironically, it is the electric utilities themselves that may provide the breakthrough orders.

A number of U.S. utilities are interested in installing PV arrays next to their utility substations to meet peak load demands without firing up expensive diesel and natural gas auxiliary generators.

In addition to Southern California Edison, other utilities that are known to be interested are Pacific Gas & Electric, Arizona Public Service, Florida Power & Light and Philadelphia Electric.

Until those big orders fall into place along with improved technology, prices are expected to remain where they are -- cheap historically, but still pricey.

Mr. Droege paid $362 apiece for a dozen 60-watt solar electric panels -- a total of $4,344. The solar panels accounted for about half the cost of the system, which also includes heavy-duty batteries and electronic equipment for regulating the way the batteries are charged and converting the power into normal alternating current for household use.

Ten years ago, the panels would have cost twice as much, said Brent Atkins, co-founder of Atlantic Solar Products, the largest East Coast PV distributor.

Mr. Atkins says that it is just a question of time before solar panel costs drop far enough so that suburban homeowners, who have access to "the grid," go solar as well.

"I think in '95 we're going to start seeing it happen. It's going to be a real sunny day. That's what I'm hanging around for," said Mr. Atkins, whose company already is generating $5 million in sales per year.

Already, there are intriguing examples of the solar possibilities the future holds. One is the micro-utility.

Coming in on the coattails of federal tax credits for solar power, a developer in Phoenix, Ariz., built a 24-home subdivision in 1985 around a central 300-kilowatt solar array. There are no batteries. The energy generated is sold to the local electric utility, which must accept it under federal laws designed to encourage renewable energy efforts.

John F. Long Properties Inc. sold the homes for about $95,000 each and operated the solar electric system as a separate entity, taking advantage of the tax credits, which were phased out in 1986. By agreement, the homeowners eventually ended up owning the solar array, which generates enough electricity to offset what they use.

"So, in effect, people living there have a zero energy bill," said Mr. Howley of Siemens Solar. "They don't pay an electric bill to the utility."

While big-name companies are starting to emerge as players in the industry, its history belongs to grass-roots types like Sam Droege.

His $9,000 system won't run all the appliances of a typical U.S. household. Aside from a washing machine, Mr. Droege and his wife, Romey Pittman, rely on the typical accouterments of a solar household: a refrigerator that can switch between electric and propane power, high-efficiency lighting and a wood-burning stove for heat.

But he points out that he and his wife have been living in their log home without any electricity until now, except for two batteries used to power a well pump.

"As far as our definition of civilized," he says, "we'll be very civilized."

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