At a certain price they would be everywhere, but if that price is achieved by not drilling for oil, building nuclear or coal power plants or implementing dopey Cap & Trade scheemes, I don't think that makes much economical sense and is in reality a de facto subsidy.
Well they have to because renewable energy is both inefficient and highly unreliable making it unsuitable for baseload-grid use thus requiring a conventional energy source backup at all times.
Well, I guess we have fundamental differences in our economical philosophy there. While for you pretty much any government meddling with the markets is an unjustified intervention, I don't always oppose the state using its powers in order to allocate resources and steering the economy towards a sustainable use of those resources, or to influence their demand by driving up or down the respective prices.
Also, Germany has almost no oil resources and the few we have wouldn't satisfy demand at all if left with those alone. Same with coal. So if we didn't promote the use of the resources we have, wind, water, biogas and a little sun, we would be perfectly independent of those countries in possession of such. Same with uranium.
For me there are a few other factors as well. If I didn't care about future generations, I would say, "Screw that green energy and use up the oil". If I didn't believe in climate change I would say, "Screw those windmills and let's take our chances with that damn global warming." Which for me, by the way, is no question of believing, and I don't really want to sit here in 40 years and say "Boo! You were wrong!" or "Yes, you were right."
If I didn't care that those resources were limited I wouldn't care for renewables either.
From an economical standpoint, of course nothing ever makes sense that prevents one from maximising his profit at the cost of future. But only if you follow the economic philosophy that there is no tomorrow. Or that climate change doesn't matter as long as we don't have waterproof evidence that it exists. I think, if we left resource allocation to the markets alone, we would just go through all those resources in the shortest amount of time, and our grandchildren would be very thankful for that.
Efficiency of renewables is increasing. And that's not a great argument. Every new technology lacks in efficiency. And some old technologies as well. A coal-power plant still has an efficiency level of about 35 percent. Nuclear power plants not much better. A conventional light-bulb emits about 95 to 98 percent heat.
We know that those forms of power generation are not always available. But we also aim for just 20 percent by 2020. Not 100 percent. And some other forms are, like water power or biogas. And we are still at the beginning of having figured out how to store energy.