That would cost money and lower the profits of the people that own/control the grid. I sometimes wonder how much money these robber barons spend on lobbying and other PR campaigns to convince that climate change isn't a problem and that the grid is just fine. It's one of those unanswerable questions I'm sure, but how much progress could be made by redirecting that amount of money to actually improving the grid itself?

the power cord has to have a data link (USB? or just networking over power line itself) through which the power outlet can tell the computer how much does the energy cost at any given time. this is a very welcome but very expensive addition to the infrastructure.