Why is my electric utility company offering a renewable energy option?

I just got a notice from my electricity provider saying that I can switch to renewable energy. They say that the level of service will remain the same and that I can switch back any time I want. There is something not right about this. If they could provide renewable energy at a lower cost than fossil fuels, I don’t see why they would have to ask my permission to switch to renewables. One thing they don’t mention is cost. Could it be that they would be charging me more? If so, they should be up front about it. The only other thing is that if renewable means a wind farm, some people might find this objectionable. Wind farms are really loud, can be an eyesore and there is evidence that they can interfere with local weather.