Considering the hassles caused by rotational brownouts, everybody seems to be praying for nature’s gentility to send us more rainfall in the midst of climate change. Mindanao’s dependence on hydro-electric plants which contribute more than 50% of the generation supply is being challenged by El Niño.
There is an advocacy that if we want to have a steady growth in Mindanao’s economy without being stymied by mother nature’s quirks, then we should review this high mix of hydro in the Mindanao grid, chairperson of the Mindanao Development Authority (MinDA) Jesus Dureza said during a media briefing recently at the Pulangi IV Hydro-Electric Plant (HEP) in Maramag, Bukidnon.
The National Power Corporation (NPC) reported a total generation supply of 933 mega- watts (MW) against the grid demand of 1,320 MW, thus a shortfall of 387 MW. Rudy Brioso, plant manager of Pulangi IV HEP, said rotational brownouts are part of the contingency measures to deliver full blast power supply for three days in the election period (May 9-11). However, he said, shortage of generation is mainly because of the inflow of water to the hydro-electric plants.
“Actually, because of the inflow we can generate as much as 255MW (in Pulangi IV) right now for only a short duration. Dali ra mahurot ang tubig,” he said. He added that because there is less rainfall, the supply will not last until December should they will comply with the rated capacity.
Hydro-electric plants at Lake Lanao (Agus 1-7) and Pulangi river, comprise 74.4% of the total rated capacity of generation mix (NPC and IPPs) in Mindanao grid. Unfortunately, these HEPs contributed only 31% of the total generation supply based on the demand-supply condition as of April 15. The seven Agus power plants, expected to generate a total of 727 MW, had a total dependable capacity of 152 MW, while Pulangi IV HEP, expected to generate 255MW, had 90MW.
The receding elevation of the two reservoirs is a crucial factor according to Brioso. As of April 15, Lake Lanao reservoir had an elevation of 698.83 masl, .72 masl less to shutdown the whole system; and Pulangi IV had 284.05 masl. In the first quarter of the year, Pulangi IV generated 160,634 MW. It is 60,053MW less than in the first quarter of 2009 which was 220,687MW.
With three generation units, Pulangi IV contributed 20% of the generation mix in Mindanao grid, which means 700,000 MWH per year. Its generation is directed to Davao City and its neighboring provinces. Currently, with only two units operating (Unit 1 and 3), its gross generation is only 65.8MW. Unit 2 is under preventive maintenance, Brioso said.
Normally, hydro contributed 53% of the generation mix, but, now it’s only 27%, according to Brioso. “That’s why we expect higher prices of power in Mindanao,” Dureza said.
And so simple logic dictates that more rainfall is needed to increase the elevation of water in reservoirs, thereby increasing the power supply. Pulangi reservoir needs to be filled with water up to 285.50 MCM in order to generate its rated capacity of 255 MW. Dureza posited that with El Niño expected to come very often, we should not rely too much on hydro-electric plants as the major source of electricity for Mindanao. “Let’s build more plants, maybe nuclear,” he said. [Lorie Ann A. Cascaro]
