Last night at a (somewhat noisy) press event, Ambient Devices showed some new gadgets that make it very simple to suss out electricity rates that fluctuate throughout the day.
If you'd like to save a buck, and give the Earth a break, you can watch for times when demand is low, and power companies drop the price per Kilowatt hour to encourage people to use up the extra juice so it doesn't go to waste. Then run power-demanding appliances such as washing machines.
Power meters aren't new, but they tend to have complex-looking screens with a plethora of data. Ambient makes it easy: The light glows green when rates are low and red when they are high. If you want more details, you can check the screen (hidden on the bottom of some models) for details like how much power your whole house is using at that moment and how much it's costing you.
The devices we saw were prototypes that will come out late this year. You can't go out and buy your own, however. Power companies that opt to work with ambient will sell them or give them to their customers. Tools like these help them get as much as they can out of their business, which saving you money, too.
Check the video to see how they work and also learn the curious, hacker-driven story of how they came about.