(UPDATE) THE National Grid Corp. of the Philippines (NGCP) issued red and yellow alerts for the Luzon and Visayas electric grids on Tuesday as energy stakeholders continue with repairs to power plants affected by Typhoon Aghon.

Likewise, the power transmission firm said that the Luzon grid will be under red alert from 2 p.m. to 4 pm and from 8 p.m. to 10 p.m. on Friday.

Moreover, the Luzon grid will also be under yellow alert for the periods 1 p.m. to 2 p.m., 4 p.m. to 5 p.m., 6 p.m. to 8 p.m., and 10 p.m. to 11 p.m.

Meanwhile, the Visayas grid will be under a yellow alert from 2 p.m. to 4 p.m. on the same day.

In the meantime, the Mindanao grid continues to operate on normal status.

A red alert status is issued when power supply is insufficient to meet consumer demand and the transmission grid's regulating requirement.

Meanwhile, a yellow alert is issued when the operating margin is insufficient to meet the transmission grid's contingency requirement.