YORK -- Robert Silknitter has worked for 38 years in the hydroelectric turbine industry here, and he had a pointed question yesterday for Democratic presidential candidate Sen. Barack Obama.

When national politicians talk about developing renewable forms of energy to lessen American dependence on foreign oil, he said, why do they always mention wind, solar and biodiesel fuel but not electricity generated by water?

"Hydro power hasn't gotten enough attention," said Mr. Silknitter. "It drives me up the walls of my living room. My wife's always telling me to calm down."

Mr. Obama smiled and said there's no need for Mr. Silknitter to climb the walls.

"You won't hear me forget to mention hydro any more," the candidate said. "That's one good thing about visiting this plant. If you don't hear me mention hydro the next time, I'll give you my card and you can call me, instead of venting at your wife."

Mr. Silknitter later showed a reporter a business card with an Obama aide's name on it. The bald, goateed worker, wearing a blue T-shirt, said, "I just felt that hydro has been overlooked for months and since he was here, I wanted to bring it up.''

Mr. Obama spent half an hour answering questions from a group of about 100 workers of the Voith Siemens hydro turbine manufacturing facility in York, a Democratic town within a Republican county.

Mr. Obama, dressed casually in dark slacks and a white shirt but no tie or coat, shook hands with many of the hydro workers. They'd gathered in chairs for an hour under a hot sun, and listened to him after he toured the plant with company president Mark Garner, U.S. Sen. Bob Casey, York Mayor John Brenner and a gaggle of reporters and photographers.

Mr. Garner said orders for his hydro turbines are picking up. One large order is for eight turbines to be located at three AMP Ohio plants along the Ohio River, in Ohio, West Virginia and Kentucky.

"With oil over $100 a barrel, hydro is definitely making a comeback" for generating electricity, said engineer John Seifarth, Voith Siemens' director of manufacturing.

During the workers' questioning, Mr. Obama passed up a chance to take a shot at Republican vice presidential candidate Sarah Palin, the first-term governor of Alaska, whom some have criticized for being short on political experience, especially on a national scale.

"I will talk about my experience and Gov. Palin can talk about hers," said Mr. Obama, who is often criticized by Republicans for his comparatively short time of four years in the U.S. Senate.

Mr. Obama criticized Republican presidential candidate Sen John McCain for "not talking about things that matter to middle-class people," such as improved access to health insurance, tax cuts for more than just the wealthy, more preschool programs, financial aid for college students, higher pay for teachers and finding alternate forms of energy."

The McCain solution to energy problems, Mr. Obama said, "is to talk mostly about more oil drilling."

Mr. Obama said he's not opposed to some additional oil drilling but said that it is -- in no way -- the sole solution to America's energy problems.

"We can't drill our way out of this problem," he said.

The visit to the hydro plant was one of two stops Mr. Obama made yesterday to largely Republican areas of south-central Pennsylvania, areas that Democratic presidential candidates have had a hard time winning.

The last Democrat to win York County was Lyndon Johnson in 1964, said state Rep. Eugene DePasquale, D-York, the grandson of well-known Pittsburgh city Councilman Eugene "Jeep" DePasquale.

But Mr. DePasquale was optimistic about Mr. Obama's chances of carrying York County this year.

"He will be very competitive," said Mr. DePasquale, predicting Mr. Obama will win the city of York by 4,000 votes, enough to overcome GOP strength in other areas of the county. Mr. DePasquale said there were 80,000 registered Democrats in the county in 2004 but there were now 110,000.

After leaving the hydro plant, Mr. Obama traveled 30 miles east to Lancaster, one of the most Republican areas of the state, for an address to a crowd in a public park.

Democratic presidential candidates have carried Pennsylvania in each election since 1992, and Democratic leaders said it's vital that Mr. Obama take Pennsylvania and its 21 electoral votes this year if he wants to be president.