I am not saying states do not have the option, but most people will choose the provider based on price.
Consider this, you cited that 47 states now have a green option, yet according to the EIA,
U.S. Energy Facts - Energy Explained, Your Guide To Understanding Energy - Energy Information Administration
only 11% of energy consumed is from renewable sources, which tells me that most people are not choosing
that green power option. The why is cost, in most cases those options cost more.
If the green options were also the lowest costs options, it would be difficult to supply the demand.
I wonder how much of this comes back to people who want to ware their Environmental consciousness
button on the shirt, being willing to pay more for a commodity, thus keeping the price artificially high?