In America there is enough land that wind can do 25% and solar can do another 25%
Wind is under a million per megawatt. Competitive with new natural gas or coal capacity - and without fuel input costs.
Solar is dropping fast. First Solar says its manufacturing costs are $.73 a watt or $730,000 per megawatt. Don't know what the installation & profit margin is but the point is alternative energy has a bigger role to play than you might think.
I see a lot of technological determinism on Slashdot. Talk about energy and everybody turns into a Soviet technocrat. They contrast dozens of elegant nuclear plants with the hundreds of thousands of wind turbines and solar panels needed and decide that former will be a better bet for the next 5 Year Plan. But the bottom line is nuclear is horrendously expensive. I recall the new Areva plant in Finland costing $5 million a megawatt. What a joke. Plus nuclear capacity is not modular enough. Utilities can't just plunk down 5 megawatts the way they can with wind or solar. The *financial* flexibility is just not there.
(The hyped mini-nuclear reactors are still unproven and undeployed after years of talk)
Finally nuclear requires a lot of smart people to keep it safe, and they are in short supply.
All of my objections to nuclear have answers, answers that depend on unproven technology, subsidies, or transformation of Congress into a bunch of engineers.
Meanwhile new wind, solar and nat gas capacity is coming online everyday.