At Alvah Bushnell, the product line has remained virtually unchanged since the manufacturer of accordion folders first applied for a patent in 1919.

The Philadelphia company has been run by the same family for six generations. The workers on the factory floor tend to stick around, too: One folder assembler retired after 70 years on the job.

"We are proud to be old-fashioned," the company boasts on its Web site, a rare dalliance with something new.

No wonder Rick Bushnell considers his next step "scary." He is taking the plant solar.

The 80-kilowatt system headed for the factory's flat roof will be one of the largest in the city and the region.

It also will be one of the most sizable business steps Bushnell has made since joining, in 1976, the company his great-great-grandfather founded in 1876.

As he talked about the decision in an interview last week, Bushnell was still coming to grips with the enormity of it all, especially the price tag: $536,000.

"It's a big investment," said Bushnell, 56, the company's vice president. His father, Arthur, 84, is president, but hasn't taken a paycheck in 25 years.

Together, both men bought the two-story cinder-block-and-stucco building that houses their business on Chelten Avenue in Germantown in 1985 for $600,000.

Now, Rick Bushnell added, "we're putting little panels on the roof for the same price."

Fortunately for the Alvah Bushnell bank account, that's not exactly accurate.

When federal and state grants and rebates are factored in, along with depreciation tax credits, the cost of the system is $62,720, said David Richman, vice president of commercial project development for Eos Energy Solutions. The Philadelphia solar-energy company expects to have Alvah Bushnell plugged into the sun by the middle of January. A new roof is needed first. Cost: $132,000.

The Bushnell solar system will be the largest East Coast project the two-year-old Eos has installed, said Andrew Kleeman, founder and managing partner.

"The current generation of Bushnells," he said, "is certainly proving to be every bit as innovative as the founder."

That founder was Alvah Bushnell, who owned a vineyard in Upstate New York until fire destroyed it when he was in Philadelphia for the Centennial Exhibition of 1876. So, impressed with Philadelphia, Alvah Bushnell stayed and opened what is now a company of 48 employees and $5 million in annual revenue.

The current generations of owners do not know when the company evolved from a distributor to a manufacturer of office folders. But it appears that when it came to energy, Alvah Bushnell had some pioneering spirit in him, too.

The family believes the company switched from gas lamps to electric lighting in 1881 or 1882. At the time, the company was in Center City at 13th and Market Streets, next to the John Wanamaker department store. The store had made the switch to electric illumination around 1880.

The Alvah Bushnell Co. would move several times over the years, in one instance to make way for a proposed Gimbels parking lot. In another, it was to return to less-expensive quarters during the Great Depression. The move to Germantown came after a landlord wanted the company out of a building at 13th and Cherry Streets in anticipation of the Convention Center's arrival.

That was in 1985. Nine years before that, Rick Bushnell had just graduated from Pennsylvania State University with a degree in law enforcement. An internship with a county probation and parole office cured him of wanting a career in that line of work. He opted for accordion folders.

The Alvah Bushnell folders are brick-colored. In the earlier years, the paper actually contained red rope, but no longer does.

For the most part, each folder is still made by hand with five pieces of paper. Machines are used for cutting, gluing, and compressing. A total of 12,000 to 15,000 folders are made daily.

The post-9/11 anthrax scare put an end to the company's direct-mail marketing to its primary customer: law firms. That is now the work of four telemarketers and four full-time salespeople, who make in-person customer calls - including another Bushnell, Rick's daughter Keiko, 26.

Two small competitors have recently been absorbed into the company. But the biggest competitor remains: China.

Chinese-made accordion folders can be as much as 25 percent cheaper, Rick Bushnell said. It's a price he can't match because his company pays its workers incentive bonuses and provides health-care benefits and a 401(k) match of 3 percent, on top of wages that range from $9 to $16 an hour, he said.

Cutting operating costs is one way to stay competitive. That is why when son Ken, 25, the company's chief operating officer, started proposing a conversion to solar, his father kept an open mind.

One big reason he did, Rick Bushnell said, is the prospect of electricity rates' increasing by double digits when state-imposed rate caps expire at the end of 2010. The 30,000-square-foot factory's electric bills currently run $3,000 to $4,000 a month, Ken Bushnell said. Eos' Richman estimates solar will save the company about $34,000 a year in electric costs, enabling the system to pay for itself in two years.

Yet not a single photovoltaic panel would grace his roof if not for the promise of government subsidies, Rick Bushnell emphasized, a little unnerved they will not arrive until the solar system is in place.

"The scariest thing for me is having to wait for the money," Rick Bushnell said. "I like having our money in the bank."