Mid-July to mid-August 2006 saw one of the worst heat waves to hit the U.S. in 70 years. Multiple record electric demands were set, with demand response programs activated more than at any time since their inception. Don't be surprised to hear some utilities pushing for money to beef up transmission and distribution (T&D) systems. It's also likely that regulators will try to reign in system-wide peak demand through higher peak demand charges, expanded demand response (DR) programs, and broader use of time-of-day and real-time pricing. Climate watchers may also weigh in on regarding how this hot spell bumped the average monthly temperature into the red zone of climate change models.


With only a few exceptions, the grid held and no major blackouts occurred. Among the exceptions was the failure of local urban power distribution systems in parts of New York City, Newark, NJ, southwestern Connecticut, Los Angeles, Cleveland, and much of St. Louis. Those cities saw a mix of multi-day outages, brief or rolling blackouts, or localized power failures due to a combination of the heat and a severe storm. Most power losses were due to overheated distribution wiring carrying record air conditioning loads, though the St. Louis blackout was complicated by downed power lines.

Seven major power grids - serving New York, New England, Mid-Atlantic states, the Midwest, Texas, California, and Ontario, Canada - posted new records for peak demand. As temperatures hit triple digits, so did spot market power prices (in $/MWh), with a few wholesale grids posting some of their highest day-ahead pricing. In areas that often see high power pricing (e.g., Connecticut), wholesale spot market prices approached $1,000/MWh (for the mathematically challenged, that's a $1/kWh).


Calls for conservation and voluntary curtailment were accompanied by the closing of some nonessential governmental and utility offices. With memories of the August 2003 Northeast blackout still fresh in many minds, such calls were finally taken seriously.

Several firms actively promoting demand response (e.g., EnerNOC and Consumer PowerLine) went into overtime pushing their customers to cut back demand and run emergency generators to supplement utility power supplies. Such firms get a piece of the incentive action paid to customers responding to such calls. The Federal Energy Regulatory Commission (FERC) in a recent study of transmission congestion (i.e., limited ability to move power) concluded that demand response options should be expanded, especially in certain locales due to demand growth. This latest brush with a blackout will doubtless add momentum to such efforts.


The National Climatic Data Center found July 2006 to be the second hottest on record for the continental U.S. (temperature data recording in the U.S. began in 1895). More than 2,300 local daily temperature records for July were broken, as were over 50 others for the entire month. The hottest July was in 1936, with 1934 now the third runner-up. Not only were daytime records broken: 90 records for the highest nighttime temperatures for July were also topped.

One of the more interesting NCDC statistics concerns the impact of this event on average temperatures. The average July temperature in the 20th century was 74.3°F, but the average during the July heat wave was 77.2°, only 2.9° higher. Next time you hear someone scoff at climate changes of "only a few degrees," remember what July's average temperature felt like.

But July was only part of recent weather history. The first seven months of 2006 were the warmest January-to-July of any year on record. While the previous January-July record temperature was 54.8° (set in 1934), the average for the same months in 2006 was 55.3°, again only .5° warmer. That little half-degree yielded a temporary glut of natural gas that drove down post-Katrina prices by more than 40%.

While no single heat wave creates a trend, one may wonder if this event should be seen as a "dress rehearsal" for global warming.

For a complete list of this summer's broken temperature records (and related data) go tohttp://www.ncdc.noaa.gov/oa/climate/research/2006/jul/julyext2006.html.