By the OGJ Online Staff
HOUSTON, May 10 -- Texas should get through the summer without threats of blackouts given the amount of available generating capacity and forecast peak demand.
The only doubts about summer reliability concern the Dallas�Fort Worth area because of known transmission constraints that are still not completely remedied. ERCOT, or the Electric Reliability Council of Texas, released its summer assessment for 2001 forecasting peak demand to be 2% lower than last summer.
The control region said it expected summer 2001 to be cooler than last year.
Peak demand is forecast to be 56,373 Mw compared with last summer's all time peak of 57,606 Mw.
Complicating the demand forecast is the possible switch of 5% of investor-owned utility customers to other retail electric providers in the Texas' competitive choice pilot program starting June 1. The pilot precedes the total choice program which begins January 2002. Because the shift of customers from one supplier to another may not be counted in the individual control area forecasts, demand could peak at 58,550 Mw, according to ERCOT documents.
Transmission constraints noted by ERCOT included power flow from south to north through the Jewett Substation in Central Texas and west to east from Morgan Creek. ERCOT said the south to north power flow will be alleviated by a new 345 kv line scheduled to go into service in May. The west to east problem will be relieved by additional lines that are still in the planning stages, ERCOT said.
Imports and exports of power are not an issue since the control area is mostly isolated from the neighboring electricity regions. The current total interregional transfer limit is only 785 Mw across two ties.
ERCOT said it expects no unit outages or any potential environmental or regulatory restrictions that would curtail capacity this summer.
New generation units and upgrades to power plants will add about 3,368 Mw of new capacity between May and September. The new power plants include gas-fired combined cycle plants, gas turbines, and wind power.
Net capacity in ERCOT ranges from 63,941 Mw in June to 64,097 Mw in September. The capacity figures do not include any expected or unplanned outages except for 560 Mw in September.
Demand takes into account interruptible load. ERCOT is counting on 2,699 Mw of interruptible load being available in June, 2,708 Mw in July, 2,870 Mw in August, and 2,690 Mw in September.
ERCOT documents show an available capacity margin of 22% or 14,432 Mw in June. The other summer months have similar available capacity margins.
ERCOT did not estimate an operating reserve margin which is the amount of unused available capability that can be applied to the system within 10 minutes at peak load. The system operator did not return phone calls.
