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IT Roundtable: The Digitized Grid
squeezing more through existing infrastructure, everyone will be better off, including utilities.
Fortnightly: How will GridWise accomplish that?
Pratt: We are trying to spur investment in technologies that connect demand-response technology to distribution systems, such as sub-stations and feeders. We can displace distribution infrastructure in very localized areas if we can communicate values about power flow among all levels of the system.
An example that we talk about a lot is the grid-friendly appliance. White-goods appliances represent about 20 percent of the peak load at any time. Instead of being a burden on the grid when times get tough, a grid-friendly appliance actually helps the grid. It has a chip in it () that can measure power frequencies very accurately. When the grid is having a disturbance, the power frequency will slow down as a power deficit is made up by all those rotating generators.
We can teach appliances to recognize this frequency shift on their own and turn off for a few minutes. They can do this much faster than you can bring power plants online to make up the deficit. This gives the grid a soft landing when it hits these deficits. It is also a cheaper resource than having plants on standby, and it takes appliances out of the problem and makes them part of the solution.
Fortnightly: How could that work? I don't imagine consumers would want their refrigerators turning off without their control.
Pratt: We're trying to make this a no-harm, no-foul technology. Appliances like dishwashers, refrigerators, clothes dryers, air conditioners, and electric heaters go on and off all the time. If you are clever about it, and you turn it off for two or three minutes, no one will notice. The chips will be built into the appliance, so the light wouldn't go off in the refrigerator, just the compressor.
Fortnightly: How would this technology work in a blackout?
Pratt: When there is a blackout, one of the hardest parts to manage is the fact that every appliance is thirsty for power. The grid operator is trying to get the grid back up and not quite making it because of the huge demand from all the loads, which effectively are trying to pull it back down again. If we create a ladder from the least-important to most-important appliance, then we can kick off appliances according to their end-use category. This could allow the grid operator to intentionally leave the frequency just below 60 Hz to signal appliances to turn off, allowing the grid to stabilize.
In other words, we can create a poor man's end-use grey-out that will replace the need for rolling blackouts.
But this technology isn't just useful for reliability management. If appliances have brains inside them, we can begin to manage loads better than we've ever done before. For example, right now your refrigerator is as dumb as a stone. It will go through its defrost cycle, which is when it uses the most electricity, at a random time, even during peak hours on hot afternoons. At any point in time, 7 percent