Mid-way through a hot, humid summer, electric
grid operators across much of the country
have managed increased demand for power
by coordinating their efforts to ensure
reliability and maintain system performance.
Grid operators responsible for managing
the flow of wholesale power across the Eastern
Interconnection–an area that stretches from
the Rockies to New England and from Arkansas
to Manitoba–have all reported record levels
of electricity usage during this summer’s
extreme heat and high humidity.
Thus far, their systems have met demand
with few problems, although some organizations
have asked consumers to conserve power during
periods of peak usage. The grid managers
credit coordinated efforts with their own
members and with other independent system
operators, or ISOs, for their continued
ability to meet high demand and to maintain
system performance and reliability.
Their experiences so far this summer in
successfully meeting high demand for power
should prove valuable throughout the remainder
of the season, they added, as well as in
preparations to meet future demands on their
respective systems.
During daily conference calls, representatives
of grid operators along the Eastern Interconnection
discuss the day’s outlook and share data
regarding projected peak demand for power
within each system. In addition, numerous
operating agreements between ISOs have improved
coordination, particularly at seams along
the borders of neighboring systems.
Under the agreements, the ISOs share critical
operating data relating to the management
of reliability and relief of congestion
within their respective systems. The ISOs
also share day-today planning data to ensure
that each grid operator can recognize and
manage the effects of its operations on
adjoining systems.
Improved coordination among ISOs also creates
opportunities to import or export power
from one system to another, as needed, to
meet demand for power. Grid operators across
the Eastern Interconnection have reported
new peak demands for power usage throughout
the summer’s extended heat wave.
* PJM Interconnection, which operates the
power grid for all or parts of 13 states
and the District of Columbia, announced
on July 26 that it had successfully met
a peak demand for about 135,000 MW, a new
record. PJM’s previous record peak demand
was 130,574 MW, reached on July 18.
* On Aug. 3, the Midwest Independent Transmission
System Operator, Inc. (Midwest ISO), which
manages the power grid for all or parts
of 15 states and the Canadian province of
Manitoba, successfully met a demand within
its reliability footprint of 131,434 MW,
topping the previous peak of 131,188 MW
set on Aug. 2.
* The New York Independent System Operator
(NYISO) announced on July 26 that, for the
second straight week, high heat and humidity
drove statewide electricity usage to record
levels. NYISO officials recorded a peak
load of 32,075 MW on July 26, breaking the
previous week’s record of 31,741 MW.
* ISO New England, Inc., (ISO-NE) which
operates the bulk power grid serving the
New England region, announced it had reached
an all-time high on July 27, topping out
at 26,922 MW. The previous record, of 26,749
MW, had been set on July 19. Prior to 2005,
New England’s record was 25,348 MW, set
in 2002.
* Southwest Power Pool, Inc. (SPP), which
manages the power grid in all or part of
seven southwestern states, has experienced
high demand this summer as well. Non-coincidental
peak for July 22 was 38,852 MW, surpassing
the previous day’s peak of 38,612 MW. With
the unusually high demand levels in the
northeast, SPP has actually seen transmission
patterns moving south to north, which is
atypical for the summer months.
One megawatt is enough electricity to power
about 800 homes, according to national averages.
All told, NYISO, SPP, ISO-NE, PJM and the
Midwest ISO supply wholesale power to approximately
142 million people, roughly 48% of the U.S.
population.
