Somehow none of the responses seem to say this explicitly: you didn't actually contradict the definition you quoted! The idea is that that solar power plant bei

Somehow none of the responses seem to say this explicitly: you didn't actually contradict the definition you quoted! The idea is that that solar power plant being built is a green project that wouldn't be possible without the additional cash from Delta... if that power plant was already able to happen without this money (which happened to be provided by Delta) then Delta didn't really buy anything and so shouldn't get any credit. And that's the issue people keep noting about these carbon credit projects: that the money spent on these credits often somehow isn't cutting emissions (as it is clearly intended to in your example, as that's the basic concept behind the market).