Of all the Subway restaurants in Minnesota -- and there were 430 of them as of March 1 -- Bill and Kim Ward's Subway in Ham Lake is among the greenest.

Signs use low-voltage LED lights rather than neon.

A hood enclosure over the bread oven forces hot air outside, reducing the need for air conditioning.

An on-demand natural-gas water heater will reduce energy costs to an estimated $168 per year.

Other Subways have installed similar features. But the Wards' store might be the state's greenest because it incorporates so many of them into one location.

Subway public relations coordinator Les Winograd said the chain has three LEED-certified "eco-stores" operating in Florida, Oregon and Louisiana.

LEED, a designation of the U.S. Green Building Council, stands for Leadership in Energy and Environmental Design.

Winograd said he knows of no other franchisee in Minnesota who has taken the example of the eco-stores and run with it the way Ward has.

That includes contacting Winograd to talk about issuing a news release to stir media interest in his new store.

Sitting in his otherwise ordinary-looking Subway off Hwy. 65 last week, classic rock playing in the background, Ward was frank about the marketing potential of being green.

It's a trendy issue, he said, especially in Ham Lake, a city with "a lot of tree huggers" that enforces a rural feel by requiring homes to be built on a minimum of 1 acre.

The owner of three other north-metro Subways, as well as the strip mall that houses his new store, Ward shows a combination of idealism and pragmatism that is common to green entrepreneurs.

Going green is "the right thing to do, when you really think about it," he said. But, he said, he looks at things "from the standpoint of business, from the Subway side of the view."

That LED light sign cost roughly 50 percent more than traditional neon, but it will save money over time, he said. Likewise, the hood over the bread oven was a costly upgrade but one that will pay off.

How much does it cost for the average Subway franchisee to go green? Winograd wouldn't say because the cost to build a new store varies depending on the location.

One eco-store franchisee told an Oregon newpsaper that his store cost $15,000 to $30,000 more than a traditional store would have cost.

Winograd wouldn't comment on that report. However, he said, the chain is using one eco-store in Kissimmee, Fla., as a point of reference to do a cost-savings analysis this year. Subway plans to share that research with future franchisees.

"It's one thing to say: Hey, this is ecologically friendly. It's another thing to show the numbers," he said.

Eric M. Hanson • 612-673-7517