it's all about offsetting the "Peak Load" requirements. Something BlueGens are already doing (in Adelaide I believe?). If electric cars start to become mainstream, then there's definitely going to be a need to offset the ridiculous Peak Load such demand would create...
http://www.news.com.au/money/cost-of-living/saving-the-world-could-cost-the-earth/story-fnagkbpv-1226525230344