Pic: AP.

The southern Philippine island of Mindanao plunged into total darkness leaving millions of people without power dawn Thursday as the electricity supply was cut off from the main grid system of the National Grid Corporation of the Philippines (NGCP).

Limited power supply did not come back until 9.30am.  An advisory from NGCP said all NGCP substations were reconnected to the backbone lines in Mindanao by noon.

NGCP said the origin and cause of the massive power blackout are still being investigated.

The blackout raised fears another round of rotational brownouts is coming as the summer months approach.

Mindanao has been facing perennial power supply problems with capacity barely meeting peak demands of distribution utilities.

The island has a rated capacity of 1,800 megawatts but the available capacity is only in the vicinity of 1,150 M. Peak demand however can go as high as 1,400 MW, sending distribution utilities scampering for additional capacities which are largely sourced from modular generating sets and power barges – all of them are run on diesel and bunker fuel – which adds up to the generation costs and electricity bills of every power consumer in the island.

Mindanao, too, is heavily reliant on hydroelectricity, with more than 53 percent of supply coming from the Agus and Pulangi hydroelectric plant complexes. 

These two power plant complexes are the heartbeats of NGCP power grid system in Mindanao.  If these are commissioned out of the grid, the whole Mindanao economy will suffer from catastrophic collapse.

Compounding the already tenuous supply situation is the locations of major power plants on the island. Until new capacities by the Aboitiz Group and Alcantaras go on full commercial stream in the southern portion of Mindanao by 2016, the island will continue to get more than 60 percent of its supply in Northern Mindanao where the Agus and Pulangi power plant complex are located.  These two power plants have a combined rated capacity of over 750MW but are operating at less than 80 per cent capacity.  Southern Mindanao eats up more than 60 percent of the island’s available power supply.

Until the new power plants begin operating, power supply will remain problematic in Mindanao.  The ongoing projects by the Aboitiz in Davao City and the Alcantaras in Sarangani are coal-fired power plants, ushering a new bias and shift in the power supply mix in the island.  These two power plant projects have a rated capacity of at least 450 MW, enough to meet the peak demand of the island. 

But not for long.  Mindanao power demand is growing by at least 4.2 percent every year.  In 2009, Philippine Chamber of Commerce and Industry said Mindanao needs to add 100 MW new capacities every year to meet the growth in demand of power supply.

Disturbing still is the government’s push to for the immediate implementation of the electricity spot market.  When fully implemented, Mindanao’s relative and competitive power rates will surely rise.

Even if the implementation is now limited, there is no sense putting any extra power supply in the spot market.  Why sell excess available capacity when the island is operating with virtually no reserve capacity?  Such a scheme only ensures that electricity will become more expensive in Mindanao.

Now, what really caused the total blackout in Mindanao yesterday? It is anybody’s guess. The NGCP better explain it very soon.