Patents have a short life span.

Years, depending on how it is used and renewed. But the point is that you've got a minefield of potential legal liabilities every time you try and launch a business. You don't know whether what you're doing is patented until you check. And if enough entrepreneurs have their businesses blown up early on, it delays how quickly alternative energy can be built out and deployed by at least as long as these patents survive.

When the government is in your corner, handing out subsidies, leaving environmental rules unenforced, securing new oil fields overseas through military force, and generally making your life as an energy tycoon easier, you're at a comparative advantage to the wind farm guy who has to argue with the Kennedys over hurting a bird or obstructing the Massachusetts Bay skyline.