... and realistically factor in the cost of upgrading the distribution network and building backup capacity.
And then we still end up with natural gas power plants and hydro taking up the slack.
The vision of an 80/20 energy mix isn't any kind of utopia. I see a future of big diesel engines, fracking, and wildly fluctuating stream flows.
Natural Gas Fueled Reciprocating engines, 163 MW total output:

Apparently that's the current plan in Northern California. Engines like these will pick up the load when the wind's not blowing and the sun's not shining.
http://www.pge.com/about/environment/pge/minimpact/humboldtbay
Building new long distance transmission capacity without first implementing a ban on coal is a bad idea because new coal plants will be built in places where the coal industry owns the government or the government owns the coal industry, and the power or industrial product will be exported to places where coal mining or coal power plants are not accepted.
Northern California doesn't import a lot of coal generated electricity because the transmission capacity doesn't exist. A few western states would be happy to build new coal fired power plants. Nevertheless, even if we resist importing coal generated electricity, our box stores are full of stuff manufactured in China in factories powered by coal.
The Eureka Wal-Mart Has Been Blessed:

Psalm 33:12 says, Blessed is the nation that has God as the Lord, said Hydesville Community Church associate pastor Jeff Beltz from a temporary podium this past Sunday.
http://www.northcoastjournal.com/blogthing/2012/06/12/eureka-wal-mart-opening-blessing
Whatever we do, if it's not done on an international scale we are all hosed. Therefore we are all hosed.