By the OGJ Online Staff
HOUSTON, Apr. 4�Electricity supplies in Illinois, Missouri, and Wisconsin are expected to be adequate this summer, but transmission serving Wisconsin remains constrained, the Mid-American Interconnect Network (MAIN) said Wednesday.
The reliability council estimated electricity resources will total 61,353 Mw, including net contracted purchases of 1,886 Mw. The summer peak load will be about 55,221 Mw. After subtracting interruptible load, that leaves a regional capacity margin of 15%, MAIN said.
The margin also assumes that all plants are operating at peak. No allowance is made for forced outages. The average forced outage rate is estimated to be about 8% well within the expected capacity margin, MAIN said.
New generating facilities totaling 5,473 Mw are expected to come online this summer, but only 1,255 Mw of the new power is committed to serve MAIN load.
With import capacity of the transmission system reduced compared to last year, however, MAIN can expect 200 Mw�1700 Mw less in import capability, depending on the region exporting the power. New generation and schedules in the regions served by Tennessee Valley Administration and in Southeastern Electric Reliability Council (SERC) are partly to blame, MAIN said.
Officials at MAIN warned that on the Minnesota-Wisconsin border transfer of power into and within Wisconsin could be subject to frequent restrictions because of parallel path flows. Parallel path flow refers to scheduled electricity transfers between two electric systems.
Last summer, MAIN experienced heavy loading on certain transmission facilities, resulting in a significant number of requests to relieve load on the transmission wires. But the requests did little to reduce the impact of parallel path flows, according to the report.
If similar conditions persist this summer, it will require �close monitoring� of system facilities and close coordination among all parties on a daily basis, the report said.
While imports from SERC, the Southwest Power Pool, and TVA have decreased, MAIN said import capability from ECAR (East Central Area Reliability Coordination Agreement) and MAPP (Mid-Continent Area Power Pool) increased.