Nighttime is the right time to plug in a hybrid, Michael Graham Richard writes in TreeHugger. If recharged after 10pm, the green cars exert less drain on power grids and may not require new power plants—meaning gas-guzzlers could be replaced without any extra pollution. But researchers at Oak Ridge National Laboratory say that if all hybrid drivers plug in at 5pm, up to 160 new plants could be needed.
Drivers will likely require incentives to plug in cars after hours, Richard admits—"but we don't think that would be a show-stopper." He recommends automatic chargers that go on after-hours when demand is low. "Fully electric cars would of course need more power than plug-ins," he writes, "but by using smart-charging and smart-metering we could use the power that we already have more efficiently."