The aisles of a typical Walgreens drugstore are stacked with products promoting their green attributes, whether they are towels made from recycled paper or makeup brushes made from fast-growing grass.

But increasingly, on the roof, a less visible green endeavor is under way, in the form of solar panels feeding power to the store.

Walgreens, which has installed 134 solar systems across the country and has plans for many more, says its solar program stems from the brand’s connection to healthful living and a bottom-line desire to stabilize energy costs.

But it has plenty of company from other big-box retailers. Large chain stores, more than any other type of business, rely on rooftop solar power to help meet their energy needs, according to a report to be released Wednesday by the Solar Energy Industries Association and the Vote Solar Initiative, an advocacy group.

“Five or six years ago, you probably would have read about a pledge in an annual report about what they’re doing for the environment,” said Rhone Resch, chief executive of the association, a trade group. “Now what you’re seeing is it’s a smart investment that they’re making for their shareholders, and this is a standard business practice.”

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Walmarts turbine is to provide 10 to 15 percent of the electricity at this Red Bluff, Calif. distribution center. Credit Alan Rider for The New York Times

Led by the likes of Walmart. Costco and Kohl’s. commercial installations of solar power have increased sharply in recent months. More than 3,600 nonresidential systems were activated in the first half of 2012, bringing the number of individual solar electric systems to 24,000, the report said.

Whether driven by brand identity or cost concerns, almost half of the top 20 commercial solar customers are major retailers like Bed Bath & Beyond and Staples.

Ikea. one of the chains in the top 20, plans to have solar arrays on almost all of its furniture stores and distribution centers by the end of the year, Joseph Roth, a spokesman, said.

Some retailers, including Walmart and Kohl’s, now routinely evaluate the solar potential of older and new buildings.

At Walgreens, solar power is becoming so common that the chain changed its standard design template to more easily accommodate the equipment. “We literally will invest in solar in any state” if it makes sense economically, said Menno Enters, director of energy and sustainability for the drugstore chain.

Retailers are pursuing other forms of renewable energy as well.

Kohl’s, a department store chain, will have 150 solar locations by the end of this year, the company said. But it is also testing wind energy and plans to expand the number of electric vehicle charging stations at its stores.

Ikea has included a geothermal power system at a new store in Centennial, Colo.

Walmart, which has 150 solar installations and plans to have 1,000 by 2020, is also experimenting with wind. It has put small wind turbines atop the lamp posts in some of its store parking lots, and it has installed a giant one-megawatt wind turbine at a distribution center in Red Bluff, Calif. The chain, which has an aggressive goal of eventually deriving all of its energy from renewable sources, is also drawing power from fuel cells in some locations, said Kim Saylors-Laster, vice president of energy for the company.

Executives say part of the appeal of the solar systems is that big-box stores are exactly that: big boxes with plenty of roof space to put up their arrays to help cover heavy electrical needs for lighting, heating and cooling and, in some cases, refrigeration.

Many of the chains began with a few installations about five years ago but have picked up the pace in recent years as the price of equipment has plummeted. The average price of a finished commercial photovoltaic system, for example, dropped by almost 14 percent between the second quarter of 2011 and the second quarter of 2012, the report said.

In addition, new financing approaches — in which third-party companies offer to install systems for little or no money upfront and instead take fixed payments for the electricity generated over a long-term agreement — has made solar even more attractive. Although the cost savings from these arrangements are not as great as for residential customers, the agreements insulate the companies against fluctuations in electricity costs, said Lyndon Rive, the chief executive of SolarCity, which provides solar products and services, and counts Walmart among its commercial customers,

“When you look at renewables, there’s not a spiking of the fuel cost,” Mr. Rive said. “You’re locking your rates, which is a great hedge for a big percentage of your energy needs.”

Ultimately, Mr. Resch said, the growth of solar at retail chains reflects a shift in mind-set.

“For most of these companies, the roof is a liability and is something they need to sink money into repairing every 10 or 15 years,” he said. “These companies are actually turning the roof into an asset. It’s a completely different way of thinking about their facilities.”

Correction: September 13, 2012

A picture caption on Wednesday with an article about big-box retailers use of renewable energy misidentified the location of a Walmart distribution center that will be partly powered by a wind turbine. It is in Red Bluff, Calif. not in Pittsburgh.