Washington ? Windmills were around for centuries before anyone thought they might generate electricity. The sun sat out there for an eternity before somebody dreamed up solar panels.

The rumble strip, on the other hand, came into being just 57 years ago, on the Garden State Parkway in New Jersey. So please forgive the guys who think they can be used to turn on lights, because they’re still working on the details.

Here’s the plan:

Rows of spring-loaded panels about the size of a cigarette carton replace traditional rumble strips at toll plazas or parking lots. When cars roll across them, a lever pushes down to spin a shaft that turns a flywheel connected to a generator.

Bingo: The lights go on.

Before you dismiss that notion, be advised that a nightclub in Holland generates part of its electrical supply from people dancing.

“If you can reduce an energy bill by 5 percent, that’s a good thing for any business,” said Gerard Lynch, the engineer who is working with a company in suburban Burtonsville, Md., to develop the concept. “A year or two from now, we hope to have something to install.”

The company, New Energy Technologies, is developing alternative energy products, including a windowpane that doubles as a solar panel.

“Solar takes longer to develop,” said Meetesh Patel, chief executive of New Energy. “We were looking for another development opportunity that we could produce with a quicker turnaround time.”

Patel and Lynch have been playing show and tell with a prototype of the rumble strip invention, first at a Burger King in New Jersey and this week at the Four Seasons Hotel in Washington. Their model is fashioned as a speed bump, which is another, more portable application for the product, but Lynch said it will work best when 30 or 40 flaps are aligned like a rumble strip.

This is not an invention intended to light up Manhattan. It won’t power the Four Seasons or provide enough zap for the deep-fryers at Burger King. The idea is that the “energy harvesters” positioned at a toll plaza might provide enough electricity to keep the plaza powered. They might cut the energy bill of a small business that has a lot of traffic in a drive-through or parking lot.

Just how much energy will they generate?

“In six weeks, we’ll be able to give you a number,” Lynch said. “It’s running on our test benches right now.”

If the concept can be mass produced economically, it offers “a piece in the power puzzle” that requires neither wind nor sun, Lynch said.