YAKIMA, Wash. — Visible from the Nob Hill Boulevard overpass are two tall chimney stacks on steel boxes atop the roof of Shields Bag & Printing.

It might surprise many to know that the box has helped the Yakima-based plastic bag manufacturer save about $15,000 a month in natural gas costs.

But recently the company received recognition. The newly established Washington Industrial Energy Leaders awards program cited Shields Bag & Printing for its conservation efforts. Another local company, Zirkle Fruit of Selah, was also recognized.

“I think it also sends a message that these are the companies that are the leading edge” in conservation efforts, said Christine Love, industrial services manager of the Washington State University Energy Program, which coordinated the award.

But there’s more to these projects than just bragging rights. The energy they have saved is enough to supply hundreds of homes, Love said.

“It would take hundreds of homes changing their light bulbs to have the same kind of effect,” she said.

Shields Bag & Printing embarked on energy conservation efforts last year after learning about funds available through WSU and Cascade Natural Gas, said Derek LaFramboise, environmental affairs manager for Shields.

After working with WSU on an energy consumption study, the company targeted a key area for savings: the oxidizers used to burn off the gases generated during the printing process for plastic bags. To reuse heat from the exhaust of the oxidizer, the company installed a heat recovery device, which heats the air as the gases enter the oxidizer. With a warmer air temperature, the oxidizer requires less natural gas to operate.

The first project saved the company 10,000 therms of natural gas a month. A therm is a unit that measures the natural gas volume by its heat content.

The project was so successful that Shields installed another heat recovery device on a second oxidizer earlier this year, which saved another 7,000 therms.

The company invested about $500,000 in the two projects, though it received about $250,000 from the WSU grant and from the incentive program with Cascade Natural Gas.

Shields was one of 56 commercial customers that took advantage of Cascade’s conservation incentive program last year, said Allison Spector, Cascade’s conservation manager, who is based in Bellingham. Last year, such efforts from both commercial and residential customers generated about 700,000 therms in natural gas savings.

Such projects help the Kennewick-based utility better manage its natural gas supply, she said.

“Instead of purchasing (natural gas) from a distributor, we’re in a way purchasing it from the customer in therms that aren’t being used,” she said.

For Shields, with the incentives and savings generated annually, the two heat recovery projects will pay for themselves in 12 and 14 months, respectively.

The effort also gives current and potential customers a positive impression of the company, LaFramboise said.

“Our customers want to deal with companies that are actively evaluating their carbon footprint and their impact on the environment,” he said. “This is one more area where we can raise our hand and say, ‘Hey, look, this is what we’re doing. We’re not just polluting.’ ”

Zirkle Fruit’s opportunity for conservation came through an incentive from the Bonneville Power Administration Energy Smart Industrial program.

The initiative, which is done through a collaboration of several Northwest public utilities, offers financial and technical assistance for industrial customers.

For the Selah-based fruit company, a facility at its fruit packing arm in Prosser, Rainier Fruit, provided the ideal opportunity for energy conservation. The building was more than four decades old and hadn’t been renovated in more than a decade.

So after an intital evaluation, Zirkle invested nearly $1.26 million for the improvements, which included new controlled atmosphere software to better control automation of the company’s evaporators, condensers and compressors, new insulated doors for cold storage rooms and energy efficient fluorescent lights in the offices.

The company estimates the improvements have reduced the facility’s energy consumption by 35 percent, saving it nearly $185,000 a year. The more than 3.4 million kilowatt hours of electricity saved annually through this project is enough to power several hundred homes.

With the $880,000 rebate from the BPA program, the project will pay for itself in about two years.

Dave Copeland, operations manager with Zirkle Fruit, notes the power lines that provide electricity for the Prosser facility are limited in capacity. The more energy the company can conserve, the better position it’s in to grow.

“If we expand by conserving our part of the world, we’re able to make more power available to us in the future,” he said.

Copeland also sees the move from a more philosophical standpoint.

“It’s what our parents did, it’s what our grandparents did, have best practices to take care of the land,” he said.

Spector of Cascade Natural Gas said she hopes such projects encourage others to embark on energy conservation projects: “We would love to see continued strengthened participation in the future.”

• Mai Hoang can be reached at 509-759-7851 or at maihoang@yakimaherald.com.