Technology Review has a future-looking story about how the widespread adoption of plug-in hybrids could have a number of benefits on top of lowering vehicle emissions. By requiring that people charge their cars during periods of low demand, power plants can operate at a higher, more level output that leads to greater efficiencies. And because more power is being sold throughout the day a greater incentive may be there for power producers to invest in clean coal and carbon sequestration technologies. The story also talks about how millions of battery-powered cars connected to the grid could stabilize the electricity system, preventing things like blackouts by letting the grid draw from the cars during high-peak periods. And, of course, each vehicle could have intelligent charging systems — connected to the Web with a unique IP address — that charge vehicles when rates are lowest or, in the case of intermittent renewables, when the wind is blowing or the sun is shining.