NERC issues summer power supply warning in key US regions

The heat is on the power industry in New England, New York, and parts of the Southwest US, including California. These areas could all be vulnerable to power outages this summer, says the North American Electric Reliability Council in its annual assessment of generating and transmission capacity.

May 24th, 2000


The heat is on the power industry in New England, New York, and parts of the Southwest US, including California. These areas could all be vulnerable to power outages this summer, says the North American Electric Reliability Council (NERC) in its annual assessment of summer generating and transmission capacity.

The report comes just days after an unexpected heat wave prompted the California Independent System Operator to declare a Stage II power alert, warning interruptible customers they might have to find other sources rather than grid-supplied power (OGJ Online, May 22, 2000).

New York and New England are projecting they might not be able to meet peak generation needs. Although about 1,000 Mw of generating capacity has been added in New England since last summer, the extra power has been partially offset by the loss of transmission capacity in Vermont, an outage at the Indian Point No. 2 nuclear plant, and the failure of the Hudson transformer serving New York City, the report says.

Shortages possible
If the area suffers a repeat of last summer's heat wave, the ability to acquire emergency energy during a capacity emergency could be "very challenging," NERC says. Despite efforts to acquire emergency sources of power and a plan to cut demand by 600 Mw in New England, the report predicts emergency procedures are likely to be used in both New York and New England during peak demand this summer.

Likewise, New Mexico, Arizona, southern Nevada, California and Baja California Norte, Mexico, could experience shortages during an extended or widespread heat wave, NERC says. Operating margins may be slim, and thermal-loading problems may require curtailment of firm demand in northern California, the San Francisco Bay area, and the San Diego area. (Firm demand includes residential consumers.) Voltage and voltage stability concerns in the Fresno and Sacramento Valley areas may require emergency operating procedures, including curtailment of firm demand, NERC says. The report blames the potential forced outages on a continuing trend of peak demand growth "significantly" exceeding the amount of new generation capacity installed.

Adequate margins in Arizona, New Mexico, and southern Nevada depend on 2,340 Mw of firm power purchases not yet under contract from neighboring systems, the NERC report says. If the additional power isn't available, some "individual entities" may have to appeal to customers to reduce loads.

ECAR a question
The probability of demand exceeding supply in the East Central Area Reliability (ECAR) coordination agreement is lower than in 1999, according to the report. But ECAR members recognize abnormally hot, humid weather and an inability to buy extra power could make it "necessary to curtail demand beyond contractually interruptible loads and demand side management," NERC warns.

Supply in some areas that experienced problems last summer has improved since then, the report says. More than 5,000 Mw of capacity has been added in Texas. All nuclear generating units are expected to be available for peak summer demand, and more than 3,000 Mw of new capacity will be available in Illinois, eastern Wisconsin, and eastern Missouri.

Drought conditions in the Southeast US have created concern. NERC says the potential exists for low river levels to affect the supply of intake cooling water for some fossil plants, leading to deratings. However, more than 10,000 Mw of new capacity will be in service in the Southeast this summer. Plus, another 1,400 Mw will be installed in the Southeast by summer for sale outside the region. But the extra capacity might be available to serve regional emergency demand, the report says.

The Northwest, Florida, the Rocky Mountain states, the mid-Atlantic states, and Midcontinent states are not expected to have major problems this summer, according to NERC, which is projecting peak demand will rise 1.7% this summer compared to 1999.

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