Mildly Interesting

So, those sort of programs are confusing and often pretty misleading. First off, you can't choose which electrons go to your house of course; all you can do is draw power from the grid. That's fine, it doesn't really matter at the end of the day, but more importantly most of those programs work by purchasing "renewable energy credits", or RECs, from wind and solar farms across the country. So what does that REC mean? Well nothing really, it just means you "claim" credit for that kWh of renewable energy. If you want you could buy them directly from some random wind farm in Kansas in theory. Or buy for twice as many kWh as you actually use- now you're 200% renewable and you're sucking carbon out of the air! Oh wait.

At the end of the day, RECs are a good idea because they provide an additional revenue source for renewable energy producers, but it isn't all that much. Last I checked they sell at like 3% of what the energy actually sells for on the grid. So for example if a wind company sells electricity for 20 cents a kWh to the grid operator, they could separately sell the RECs for that power on the open market for something like 0.6 cents per kWh, if the grid operator doesn't want the RECs for themselves as part of the power purchase agreement.

I myself subscribe to Arcadia, which is one of those companies that promises to make your power 100% green via purchase of RECs. I consider that to be false advertising. But, I still do it because it does help drive the market for RECs which is good because the ability to sell RECs makes producing green energy a bit more viable, which in turn hopefully spurs growth in the industry.

So in conclusion, it's a good thing to do, but not as good as you might think based on how it's presented. Sorry for the wall of text.