Bainbridge park officials are about to hit the roof, thanks to high energy bills.

And they are pretty excited about it, actually.

As part of a wide-ranging program to cut down on energy use and save taxpayer money, the Bainbridge Island Metro Park & Recreation District will install a solar thermal system that will help heat the water in the district’s public pools.

The system consists of panels of pencil-sized tubes that will be placed on the roof above the Don Nakata and Ray Williamson pools. A pumping system will send pool water to the roof of the aquatic center, where it will be heated by the sun before it flows back into the pools.

“Basically, it’s a no-brainer project for cutting energy consumption,” said John DeMeyer, recreation services director for the district.

The district has an annual power bill of roughly $350,000.

Keeping the pools heated is the biggest part of the bill; the district heats about 400,000 gallons of pool water a day.

“It’s a tremendous energy user,” said Terry Lande, executive director of the parks district.

The square footage of the pools, and high evaporation rates, are the main reasons.

“You’ve got water that you’ve got to heat 12 months out of the year,” he explained. “And almost six months of the year, we’ve got  enough solar power to just put it right directly into the water without the energy loss of making electricity and then using the electricity. That’s expensive to do, and it’s not very efficient.”

The piping system, made of a polymer material by Fafco, Inc., a California company, will heat the pool water to 120 degrees as it moves through the tubes.

“It’s pretty amazing. But it is just so low-tech,” DeMeyer said. “The only thing that moves is the pump.”

The system will heat pool water April through October.

“During the summer, it would take care of all of the pool heat, 100 percent,” DeMeyer said.

Early estimates for the system peg the cost at $26,000 for the Williamson Pool, and $43,000 for the Nakata Pool.

District officials estimate the two projects will pay for themselves in less than four years.

Parks officials are also taking other steps to save power.

Some projects have already been completed, such at adding insulation in some facilities and installing double-paned windows.

Energy-sucking lighting systems are also being replaced.

More modest steps have also been taken. The temperature of the Williamson Pool was dropped 2 degrees — from 82 to 80 — and the pressure in the showers has been lowered.

The pools are also getting heat-saving blankets that will reduce heat loss. The pool cover for the Williamson Pool is expected to save more than $8,500 by itself over the course of a year.

District officials have gotten approval from the parks board to purchase the thermal system to warm up the water in the pools, and they hope to have it installed and running by May 1.

“We’re going to move as quickly as we can, because we’re coming right up on the heating time,” DeMeyer said.

“It’s not going to do us much good to get it in by Sept. 1,” he laughed.