The gloomy economy and falling oil and gas prices have put the damper on plenty of clean-energy projects, such as T. Boone Pickens’ big Texas wind farm. But today’s storm clouds are just a passing phenomenon, if Wal-Mart’s plans are any indication.

The Bentonville, Arkansas-based retailer just announced a deal with Duke Energy to use wind power for 15% of the electricity at hundreds of its Texas stores. The wind will come from a Duke wind farm slated to go operational next spring.

What’s interesting about Wal-Mart’s announcement is the company’s long-term bet that using wind power will be cost-competitive with traditional power sources. Wal-Mart’s vice-president of energy said in a statement, “We’re purchasing renewable power at traditional energy rates,” though the company didn’t disclose specific terms.

Wind power is intermittent, but it isn’t volatile. That is, the electricity generated by wind farms is generally sold at fixed prices in long-term contracts to utilities and other big users. Natural gas, one of the big and growing sources of power in the U.S., has the opposite problem: it’s a constant source of power, but prices can fluctuate wildly. That’s one reason power prices in Texas spiked earlier this year.

U.S.government energy analysts expect natural-gas prices to say low next year because of weak demand in the slumping economy—which isn’t the best of news for renewable energy in the short term. Even plenty of renewable-energy enthusiasts worry that slumping fossil fuel prices will take the steam out of clean energy.