Ann de Rouffignac
OGJ Online
HOUSTON, Nov. 29 -- City Public Service of San Antonio filed an emergency petition Wednesday with the Electric Reliability Council of Texas to limit the monetary benefit that wholesale players can gain by deliberately overscheduling electric load and generation.
A recent report by staff of the Public Utility Commission of Texas revealed that a few wholesale market participants received more than $86 million during 15 days of August as a result of consistent overscheduling of load and generation across congested transmission lines.
San Antonio's petition would limit gains from overscheduling to 20% of an individual player's metered load consumption in a given zone or 400 Mw, whichever is less. When market participants overschedule load or generation on congested transmission lines, ERCOT pays them not to operate power plants or to reduce load to keep the grid stable.
"The 20% limit is still abusive," said Dan Jones, director market policy and planning of CPS. "We're not sanctioning overscheduling. We are just placing a cap on it as the weather cools down. There might be some congestion on the lines."
There is no penalty in ERCOT for overscheduling. The costs of this market behavior are borne by all schedulers in ERCOT while only a few players reap the benefits. The existing rules do not require schedulers to submit accurately balanced schedules systemwide or within zones.
ERCOT is developing an alternative method for allocating congestion costs called 'direct assignment' to avoid excessive imbalance charges from being shared by all market participants. The method assigns the costs of congestion to those participants that caused it.
That system is expected to be in place by mid-February. Meanwhile, San Antonio asked ERCOT to implement its rules proposal on an urgent basis.
"We will consider the petition tomorrow and decide how to act on it," said Heather Tindall, spokeswoman for ERCOT.
