could be achieved solely with infrastructure investment.  Even if it could be accomplished, who's going to pay for it?  Energy companies have no incentive because they make more money in the current system.  

As individuals, we expect that installing a few low energy light bulbs, replacing our appliances with more energy efficient ones when the old one wears out and plan to get a more fuel efficient auto with our next purchase will solve everything.  It won't.  Our houses my be more energy efficient, but they're also bigger and stuffed full of more electronic stuff than they were thirty years ago.  Hence, on a per capita basis, a state like CA that was a leader in energy efficiency is running in place.  Better than most other states, but it's not getting us to where we need to be.  (Same with automobile mileage and emissions standards - the CA fleet uses less gas and emits fewer toxins but those gains were wiped out and then some with more by vehicles and roads.

Absent the institutional and personal will, this country doesn't tackle major, national domestic problems.  It took a severe depression (and a war) to shift the national will to one that embraces a collective investment in the future.  Relying on technology and the conscience of individuals and institutions isn't, IMHO, going to get us there.  If we're lucky a black swan short of a depression will appear that kicks our butts into gear.  Otherwise, we'll have to live with the consequences of our shortsightedness.