CEO's got their hour in front of Congressional leaders recently and it didn't have anything to do with shady business policies or questionable balance sheets. 

Chiefs of Walmart, IBM and General Electric sat down in front of the Pelosi-minted House Select Committee on Energy Independence and Global Warming to talk green power and smart grids.

The three heads have made laudable steps to reduce their impact on the environment by turning to renewable energy usage; their comments in Washington furthered the conversation on how businesses can lead the way toward a green energy future.

Walmart in particular has made drastic reductions in packaging use in 2008.The company is also a member of the Demand Response Coordinating Committee a consortium of power companies aiming to diversify their energy sources and move toward real-time electricity pricing.

But the catch 22 for large retailers is how to grow a business in a recession while reducing impact on the planet. It is still an unsolved challenge and one that companies will have to increasingly grapple with if the economy slips futher.

Another question is how much retailers will do to go green voluntarily especially when it may affect their bottom line. Walmart, the world's largest retailer, doubtlessly has a lot more room to experiment with environmental measures that may affect their bottom line than mid-sized retailers and small businesses. So what kind of incentives should government provide for retailers to go green? Or is now time to use a bit more coercion and mandate changes across the board?