Manila, Sept. 1 -- Power supply continues to be an issue in both the Visayas and Mindanao grids, prompting the issuance of red and yellow alerts anew for Tuesday.

The Visayas grid is on red alert from 2 p.m. until 9 p.m., and yellow alert from 1 p.m. to 2 p.m, and from 9 p.m. to 10 p.m., the National Grid Corporation of the Philippines (NGCP) announced.

This is because available capacity is estimated at around 2,168 megawatts (MW), well below both demand and the grid's regulating requirements.

Capacity is limited by, among others, the forced outages of major coal-fired power plants, namely Unit 1 of Therma Visayas Inc. (TVI) and Unit 3 of Panay Energy Development Corporation (PEDC).

NGCP said supply imports from the Mindanao grid are...