Smarter electric grid key to saving power, I

at certain times of the day. He can set rules for different kinds of days, so the house might be warmer and darker on summer weekdays when his family is out. The family can override those changes manually, whether it is by turning on the porch light or raising the thermostat to ward off a Canadian chill. The system guards against waste, though. If midnight comes and no one has remembered to lower the thermostat and turn off the porch light, those steps just happen.

Programmable thermostats and other smart home controls let people craft similar resource-saving plans. The big change here is the combination of these controls with that blinking amber light on the switch — where the grid talks back. Milton’s local gas and electricity retailer, Direct Energy, will set those amber dots blinking in an emergency. It might happen a few times in a summer month. Maybe there will be congestion in Ontario’s overtaxed transmission network. Perhaps a power plant will be down for maintenance. Or rapacious air conditioners will overwhelm electric capacity. Whatever the cause, at that moment, this section of the grid needs a reduction in demand, fast, or else outages loom. People in Milton’s test are expected to configure a “brownout” setting on their computers, indicating how their homes should respond in such a situation. In this test, Direct Energy also will enforce conservation remotely. It can raise the set temperature in a participant’s home by 2 degrees Celsius in the summer (nearly 4 degrees Fahrenheit), reducing its air conditioning load. The company also has permission to shut off the testers’ hot-water heaters and electric pool pumps for four hours at time during these power emergencies. This latter policy is controversial as it appears unlikely that broad swaths of the public will accept remote control from the power company. California officials recently had to back away from a proposal to require remote-controlled thermostats in new buildings. So a more likely scenario is that consumers will get powerful economic incentives to make those decisions themselves.

Typically we pay a flat rate for electricity, even if sometimes it falls below the actual costs of supplying power at a given moment. In a growing number of places, rates move slightly higher in hours that typically are busiest. An advanced notion of this will be tested this summer in 1,100 homes served by Baltimore Gas & Electric. Pricing plans will vary, but generally the households will pay the cheapest, “off-peak” rates most of the time. Some testers will pay higher rates every weekday afternoon. And all of them will be subject to “critical peak” periods of even higher charges, declared on as many as twelve weekday afternoons with stress on the grid.

Tomorrow: Smart grid technologies