The trouble with the idea that technology will drive this change is that it's just driving down the cost of fossil fuels to below the new technologies as countries like Saudi Arabia desperately try and make sure they sell all of their oil. In order to avoid global warming we need to leave fossil fuels in the ground and that's just not in the interest of fossil fuel producers, and because for a lot of those fuels extraction is a tiny portion of the price they can afford to undercut renewables all the way down the cost curve until the pumps run dry or the renewable energy manufacturers give up and go out of business.
Fuel costs are just one part of the infrastructure, as fuels get cheaper, capital costs will dominate. (And they already do for, say, cars where less than half of the per mile costs are for fuel.) At some point I believe the capital costs will be less for renewables than for any fossil fuel based system.
Of course if we were to price in the negative externalities, I think that renewables would already be cheaper. But this is one case where ideology has prevented us from setting up an efficient market for energy.
