THE Mindanao-wide rotating blackouts (or brownouts, for the squeamish and the euphemistic) have again resumed. It is being worst in Davao City where the daily power-outs inflicted on its customers last for five hours, while they last for one to two hours in most places in Mindanao.
The public relations flacks of the PSALM-NPC and the other generating companies are again deceiving Mindanao power consumers by saying that: (a) the cause of the rotating brownouts is the prolonged drought that has reduced the generation from the hydroelectric power plants on the Agus River, and (b) the intolerably long blackouts in Davao City are just indicators of “teething problems” of the AboitizPower ThermaSouth 300 Megawatt coal-fired power plant.
However, the truths are: (1) the Mindanao-wide power-outs during the summer months have been caused by mismanagement and incompetence of the PSALM-NPC in the operations of its power plants in Mindanao; and (2) the Davao City power-outs are caused by wrong decision-making and design errors in the interconnection system of the Aboitiz coal-fired power plants, which are permanent problems and not problems of immaturity.
Mismanagement and incompetence of the PSALM-NPC
The main contributory factor to the Mindanao-wide power outs that have been occurring during the summer months since 2010 is the mismanagement and incompetence of the PSALM-NPC. They are supposed to operate their owned or controlled power plants following the Rule Curve for Lake Lanao, but they have been consistently violating that rule.
The Rule Curve is a simple rule that can be easily followed by any sensible generating company: The annual operations of PSALM-NPC power plants should be operated so that at the end of the year the lake level will be at least 701 meters above sea level. This means that enough water will be stored in Lake Lanao to keep the Agus River hydropower plants operating at one-half or more of their normal total generation until the end of May when the water in the lake can be replenished by the rains hopefully in June.
But the PSALM-NPC has been consistently greedy for short-term profits. So every year, they operate their power plants in order to maximize the profits during the year. They do not care that another inevitable consequence of profit-maximization is low lake level at the end of the year, and rotating power-outs throughout Mindanao during the summer months.
The continuing mismanagement by the PSALM-NPC of the operations of its Mindanao power plants is enough reason for the government to fire all the officers of the PSALM-NPC. Or to abolish the PSALM.
Wrong decision and design errors
The article from the Mindanao Development Authority (MinDA) on the five hours rotating power-outs in Davao City says that the cause of the outage of the 150MW Unit 1 of the AboitizPower Therma South coal-fired power plant was due to a “tree that fell on the 138-kV Davao-Toril transmission line of the National Grid Corporation of the Philippines.”
Meaning, the transmission line has been wrongly designed because there is no transmission line to which a base-load power plant is connected should be vulnerable to normal vegetative hazards such as falling trees, wind-blown branches and palm-leaves.
An example of a correctly designed and constructed interconnection of a base-load power plant is the 138-kV transmission line of Cagayan de Oro Electric Power and Light Co. (Cepalco) for its 165MW coal-fired power plant in Balingasag, Misamis Oriental. This will not suffer any outage due to trees falling.
The decision-error of the AboitizPower that resulted the previous and recent outages of its Units 1 and 2 is due to embedding the coal-fired power plant in its distribution system instead of connecting them directly to the Mindanao transmission grid now operated by the NGCP.
This is a decision error committed also by Cepalco and the Alcantara Group for their coal-fired power plants.
The economic reason of these generating companies is saving on the transmission charges for power sold to their own distribution utility company. But, by not connecting directly to the Mindanao grid, the coal-fired power plants could not avail of the reliability provided by the transmission grid.
The result of connecting directly to the distribution system instead of the Mindanao grid will damage the coal-fired power plants due to major outages of the relatively unreliable distribution system. This has been demonstrated in the previous outages of the AboitizPower Therma South plant. And this will continue to occur for as long as it is embedded in the distribution system.
It will also be the cause of frequent outages for Cepalco and Alcantara coal-fired power plants when they start operations.
The generating companies have overlooked the fact that their coal-fired power plants are designed for base-load operations (as all coal-fueled power plants are); meaning the power plants should operate 24/7 at full-load. But distribution systems are not 24/7 reliable. And when power plant operations are abruptly stopped while operating at full load, serious damages will occur on the power plant, usually on the more vulnerable parts such as the turbine blades and the boiler tubes. Such damages take many days or weeks or months to repair. Oops! There goes the savings of the power plants from avoiding transmission charges.
No, the Mindanao blackouts under the Aquino administration have never been caused by the drought to which the government flacks have attributed to the blackouts. They have been caused by a persistent drought of sensibility in the minds of the officers of the PSALM-NPC. (Their minds are also characterized by malice-aforethought for Mindanao power consumers in the privatization of the Mt. Apo geothermal power plant. But that's another story that we will ventilate next.)
And the Davao City power-outs are not teething problems but will become frequent occurrences while the coal-fired power plant is embedded in the DLPC distribution system. (David A. Tauli)