[mjn]

One place to look for numbers more solid than people just claiming they would pay more, could be in areas with deregulated markets for home electricity, like Texas, where people have a choice of generation provider. Since generation is decoupled from transmission and maintenance, providers don't compete on reliability, but mainly on price and environmentalism. The "green" plans are typically $0.02-$0.04/kWh more expensive than the cheapest plans. Would be interesting to know what proportion of people opt for one.

Examples of such a provider and the plans: http://www.greenmountain.com/texas-oncor

[ag80]

Centerpoint has some overall price data they monitor at http://www.mytruecost.com, though at present it doesn't include distinctions between electricity sources. I submitted some feedback via their contact form suggesting they should put some data together.

[ag80]

They put a blog post up here: http://www.mytruecost.com/news/2013/10/3/how-green-are-truec...

[toomuchtodo]

I live in Schaumburg, a suburb of Chicago. Recently, ballot measures were passed by local communities across Illinois that allow the communities to collectively negotiate with power providers for their citizens. I used to pay ComEd (incumbent generation/transmission provider) 7-8 cents/KwH for power (nuclear-generated by their Byron, IL facility). I know pay a provide 5.5 cents/KwH for "green" (wind-generated) power. The cost for non-renewable power was only 0.5 cents cheaper per KwH.