GENERAL SANTOS CITY – Barely a week after President Benigno ‘Noynoy’Aquino III told Mindanaoans that the days of cheap power are over in the island, residents here are beginning to experience as much as six hours of brownouts after the Pulangi IV hydroelectric was shut down on Tuesday for a long-delayed maintenance schedule.

In General Santos City, the National Power Corporation (Napocor) further reduced its power supply to the South Cotabato II Electric Cooperative from 70 megawatts (MW) to mere 45 MW which resulted in a 3-hour rotating brownout beginning Tuesday.

Socoteco II officials however said beginning Thursday, rotating brownouts will further increase to 4 hours.  The power interruption will last until mid-May when the Pulangi IV plant resumes operation, according to an earlier advisory from Socoteco II.

In March, Socoteco II manager Rodolfo Ocat said the load curtailment earlier announced by Napocor for the month of April would have meant a 6 to 8 hour power interruption in the city.  The electric cooperative however was able to secure an additional 7 MW supply from diesel-fired power barges of Therma Marine Inc., bringing to 30MW the total additional power supply coming from the Aboitiz-owned company.

Socoteco II has a peak demand of 105 megawatts but only has a combine supply total of 75 megawatts.

In Davao City, Davao Light and Power Co. (DLPC) said it may result into a 30-minute daily power interruptions if Napocor increases the load curtailment assigned to the distribution company.

DLPC has a 50 MW diesel-fired standby power plant and has also purchased 30 MW from the Sibulan and Tamugan hydro plants.  DLPC and both the 26 MW Sibulan and the 4 MW Tamugan hydroelectric plants are owned by the Aboitizes.

In a press statement Wednesday, DLPC said it will result into rotating brownouts once the deficiency in the Mindanao grid reaches 320 megawatts.   So far, Davao City has been spared by power interruptions.

The National Grid Corporation of the Philippines said the system-wide curtailment level in Mindanao was up to 261 MW and the total system capacity in the Mindanao grid has been reduced to 1,022 MW.

President Aquino last week said the peak demand in Mindanao is at 1,300 MW.

In Cotabato province, where the 100 MW Mt. Apo Geothermal Power Plant is located, the rotating brownouts are even longer – from 6 to 8 hours.

The same situation is being experienced by Bukidnon residents.

Bukidnon Second Electric Cooperative (BUSECO) general manager Edgar Masongsong said their supply from Napocor has been reduced to 8 MW.  He said they are now negotiating for an additional 7 MW from Therma Marine Inc. on top of the 5 MW they have already contracted.   Daily load demand in his franchise area however is from a low of 17 MW to 23 MW.

Masongsong said they now are forced to cut power supply from six to eight hours in the areas covered by their two sub-stations.

In Iligan city, the Iligan Light and Power Company had earlier announced a two-hour rotating brownout once Pulangi IV is shut down.  As of yesterday, however, the city has been brown-out free.

In 2010, most of Mindanao also suffered from rotating brownouts of up to 9 hours due to the prolonged dry season, when the water level in Lake Lanao dropped to below critical levels.

Fifty-three (53) percent of Mindanao’s power supply comes from the Agus and Pulangi hydroelectric plants which have a combined installed capacity of more than 900 MW.  Their actual capacities were however reduced to less than 600 megawatts due to poor maintenance and heavy silt (in the case of Pulangi River).

Business leaders and industry players have repeatedly warned that Mindanao will suffer massive power interruptions if no new capacities are added to the existing available capacities by 2014.