> As a member of the public, I have never been asked where I want my electricity to come from, so my interest has little bearing on what actually gets built.

Really? Here in the UK every energy supplier offers a "green tariff" (usually at a slightly higher rate) where a proportion (or all) of the energy is derived from green sources. There's some shenanigans with trading of certificates which means it's not quite as straight forward as that, but still I believe this does end up subsidising green energy.