Manila, Sept. 11 -- The capacity of the Visayas and Mindanao grids remains way below the contingency and regulating requirements, resulting in red and yellow alerts on Friday.

The Visayas grid is on red alert from 3 p.m. to 9 p.m., and on yellow alert from 1 p.m. to 3 p.m. and from 9 p.m. to 10 p.m., according to an advisory from the National Grid Corp. of the Philippines (NGCP).

Available capacity is estimated at 2,330 megawatts (MW) while peak demand is expected to reach 2,002 MW.

The low capacity was attributed to the unavailability of Units 1 and 2 of Therma Visayas, Inc. and Unit 2 of Panay Energy Development Corp., as well as fewer imports from the Mindanao grid.

The NGCP said nine power plants are unavailable this month alone, ...