With the rapid decline of solar technology pricing, solar energy will be able to compete with coal in the new couple of years. The price per watt has declined from $60 to $1.50 in the past 30 years. So far, in this year alone, 17 gigawatts of solar technology has been installed; that's like constructing 17 new solar power plants!
Kamp, Jurriaan. "Hello solar, goodbye coal | OdeWire." OdeWire | News for Intelligent Optimists. http://odewire.com/177044/hello-solar-goodbye-coal.html (accessed Feb 2, 2012).