Short-term thinking doesn't favour renewables
The title is kind of obvious by itself, but the way the deregulated energy market has gone (thank you Tories of the 80s and 90s, along with everyone else who loves total deregulation), it's all less about generation and more about the trading floor. As a result, electricity companies are quite happy to sell you power at the market rate ("We're not even making anything on it!") knowing that since you're paying up front, they'll enjoy playing with your cash in advance of having to spend it themselves. Thus, as long as the electrons keep coming, a utility company can quite easily be like some kind of financial services operation with the only risk being that they can't cover their commitments when the time comes to pay up (and which actually happened to a company I bought power from once).
Now, that's the retail end of the business. But with the punters now paying whatever the market rate is ("It's wholesale, so you're getting it at the rate we pay!"), there's no incentive to keep the supply inexpensive or stable. If gas prices skyrocket, all people get to hear is, "We're not overcharging, that's just what we have to pay ourselves!" Punters think they're on the inside, not paying a mark-up, when the mark-up is now factored into the cost price of the stuff needed to push those electrons around.
So, given this sad state of affairs, try and imagine an actual power generating company actually thinking further than the next financial report, short of the regulator pointing a sharp stick at them. Sure, the generators keep putting lots of new capacity online - why wouldn't they when they can pass all the costs on to the consumer and have the consumer thinking that they're getting "a great deal"?
So, yes, you need subsidies to encourage other stuff. Because with everybody but the consumers making huge profits from finite resources, there won't be a change in behaviour until those resources are depleted. I don't see why there has to be a "Boo! Subsidies!" attitude - the public should expect the government to intervene if they're getting poor treatment from a bunch of corporations with a perpetual short-term interest in fleecing consumers.
(Booing and hissing at "state intervention" is a great way either to pander to corporations who actually don't need that kind of cheerleading for "business as usual", or to look ignorant supposedly in the name of "small government" and "fiscal prudence".)