Just back from visiting the family in Pennsylvania, where temperatures were hitting the high 90s. It was the kind of sticky, muggy, oppressively hot weather that reminds me why I live in the cool corner that is the Pacific Northwest.

As air conditioners were blasting away everywhere and lights were flickering, I was thinking that grid operators must be calling on every demand-response resource they could.

Back into post-vacation action, I came across an Aug. 10 release [PDF] from PJM Interconnect that confirmed it. The power grid was on emergency status and PJM, in fact, drew a record demand response — 1,945 megawatts — equal to a fair-sized city.

PJM also reduced voltage in the overall system by 1,000 MW, explaining those flickers. So I actually lived through the scenario with which I opened “Adventures in the smart grid no. 2.” Damned glad they kept those air conditioners on.

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