Anatomy of the Mindanao Power Crisis
Ryan D. Rosauro, PDI Mindanao
ILIGAN CITY—The prospect of longer periods of darkness looms in Mindanao barely two months after rotating brownouts first started mid-January, unless additional power generating capacities can be made on-stream in its electricity grid within the soonest time possible.
On the morning of March 4, power generation deficiency reached a new high of 650 megawatts; peak load demand was expected at 1,361 megawatts with only 711 megawatts available capacity. The capacities of hydroelectric plants were very limited due to the alarming level of water in the reservoir.
Already, this situation is showing how the country’s Power Development Plan (PDP) has failed to respond to the needs of Mindanao.
Apart from a radically lowered available capacity, rising demand is putting more pressure on Mindanao’s existing power generation capability.
Based on data provided by the daily advisories of the National Grid Corporation of the Philippines (NGCP), the problem of power generation deficiency began to reach crisis proportions on February 23.
Prior to this, brownouts lasted two to three hours. But by February 23, the outages last at least four hours.
A February 23 NGCP advisory mentioned that deficiency the previous day (February 22) stood at 183 MW. Hence, the radical rise in power generation deficiency in Mindanao started on that day, from 183 megawatts to 358 megawatts.
Earlier, on February 10, NGCP placed Mindanao under red alert status because its contingency reserve in power generation was down to zero.
Beginning February 9, one 105-MW unit of the Mindanao Coal-Fired Plant was not running due to planned outage. During this day also, the 90-MW diesel-fired plant of Western Mindanao Power Corporation also reduced generation to 80 MW; and two 28-MW units of the National Power Corporation’s (Napocor) Agus 5 and the 35-MW Iligan Diesel Power Plant (IDPP) were not available.
But by mid-February, these capacities—totaling some 206 megawatts--had returned to serviceability, except the 35-megawatt IDPP.
It was the radical decline in hydro-power generation that plunged the island into more darkness on February 23.
Between February 11 and February 23, available capacity plummeted 197 megawatts, from 1,039 megawatts to only 842 megawatts. During this same period, hydro-power generation went down by 183 megawatts, from 428 megawatts to only 245 megawatts.
Within a week of the crisis, there was a new twist in the power situation: a sharp rise in peak load demand. Load curtailment, that is the reason for the outages, is called in during the peak load hours so that available capacity is not strained.
Between March 1 and the morning of March 2, generation deficiency sharply rose 104 MW, from 390 MW to 494 MW because of a steep 106-megawatt increase in peak load demand. The deficiency climbed further by 84 MW in the afternoon because of a rise in peak load demand by a similar magnitude.
From February 23 to March 1, peak load demand is only within the 1,200-MW to 1,220-MW range. The steep rise in peak load demand on March 3 therefore set a new pattern. The NGCP has not responded to queries about the reason for this rise in demand.
This is aggravated by the further lowering of hydro-power generation capacity which in turn dwarfed the additional contribution of IDPP that was already running by March 2, producing at least 30 MW of power.
Crisis numbers
The following figures show the anatomy of the current power crisis in Mindanao.
Table 1: Mindanao Power Generation Deficiency
| Dates | Available Capacity (in MW) | Peak load (in MW) | Generation Deficiency (in MW) | Increase/ (Decrease) in Deficiency (in MW) |
| Feb11 | 1,039 | 1,195 | -156 |
|
| Feb23 | 842 | 1,200 | -358 | 202 |
| Feb24 | 863 | 1,220 | -357 | -1 |
| Feb25 | 876 | 1,210 | -334 | -23 |
| Feb26 | 900 | 1,210 | -310 | -24 |
| March 1 | 820 | 1,210 | -390 | 80 |
| March 2 AM | 822 | 1,316 | -494 | 104 |
| March 2 PM | 822 | 1,400 | -578 | *84 from March 2 AM *188 from March 1 |
| March 3 AM | 808 | 1,318 | -510 | *(68) from March 2 PM *16 from March 2 AM |
| March 3 PM | 836 | 1,334 | -498 | *(12) from March 3 AM *(80) from March 2 PM *4 from March 2 AM |
| March 4 AM | 711 | 1,361 | -650 | *152 from March 3 PM *140 from March 3 AM |
Mindanao continues to be dependent on hydroelectric plants to generate its power needs. Although its share in the power generation mix declined by more than 13 percent from 2002, hydro-power still accounts a hefty 55.22 percent of the island’s power source in 2008, the Department of Energy’s 2008 Power Statistics showed.
Since commissioning in 2006, a coal-fed plant in Misamis Oriental has tripled its contribution but still accounting for only almost a fifth of the 7.97 million MWh power generated in 2008.
From 14.3 percent in 2002, geothermal power has declined its share in the mix to only 9.96 percent in 2008.
In 2002 and 2003, the generation of oil-based power generating plants increased as hydro-power decreased. Since 2006, at the time the coal-fired plant is already available, oil-based sources has gone down, and it is now the coal-fired plant that responds to the rise and fall of hydro-power generation.
Table 2: Mindanao’s Power Generation Mix (in percentage), 2002-2008
| Year | Coal | Oil-based | Geothermal | Hydro | Solar |
| 2002 | - | 17.00 | 14.30 | 68.70 | - |
| 2003 | - | 26.10 | 13.10 | 60.80 | - |
| 2004 | - | 27.03 | 12.84 | 60.13 | - |
| 2005 | - | 32.03 | 12.33 | 55.62 | 0.02 |
| 2006 | 6.42 | 22.55 | 11.41 | 59.60 | 0.02 |
| 2007 | 19.91 | 18.74 | 10.99 | 50.34 | 0.02 |
| 2008 | 18.80 | 16.00 | 9.96 | 55.22 | 0.02 |
The predominance of hydro-power generation in the electricity generation mix of Mindanao explains why the island is continually vulnerable to a prolonged dry spell that lowers the water inflow that runs the turbines of hydroelectric plants.
Table 3: Hydro-power generation
| Dates | Combined generation (in MW) | Increase/ (Decrease) in power generation (in MW) |
| Feb10 | 428 |
|
| Feb23 | 245 | -183 |
| Feb24 | 252 | 7 |
| Feb25 | 265 | 13 |
| Feb26 | 245 | -20 |
| March 1 | 165 | -80 |
| March 2 | 140 | -25 |
| March 3 | 127 | -13 |
The February 10 figure for combined generation is a computation based on the NGCP advisory indicating that the Pulangi plant had reduced its capability by 75 percent while the Agus complex was only running at 50 percent capacity.
Table 4: Comparison between total generation deficiency and hydro-power generation, Mindanao
| Dates | Available Capacity (in MW) | Increase/ (Decrease) from previous date (in MW) | Increase / (Decrease) in hydro-power generation (in MW) |
| Feb11 | 1,039 | -- |
|
| Feb23 | 842 | -197 | -183 |
| Feb24 | 863 | 11 | 7 |
| Feb25 | 876 | 13 | 13 |
| Feb26 | 900 | 24 | -20 |
| March 1 | 820 | -80 | -80 |
| March 2 AM | 822 | 2 | -25 |
| March 2 PM | 822 | 2 | -25 |
| March 3 AM | 808 | -14 | -13 |
Table 4 shows that the drop in hydro-power generation accounts for a significant drop in total available capacity. The February 26 situation is an exception.
The rise in capacity on March 2 is that although hydro-power generation dropped further, additional 35-megawatt capacity was provided by IDPP.
Receding water
The NGCP generally points to the worsening decline in power generation capability of the hydroelectric plants for the drop in available capacity to generate electricity for the Mindanao grid.
The hydro-electric power generating capacity, currently owned by the National Power Corporation (Napocor) comprises six plants along the Agus River that snakes down from Lanao del Sur towards Iligan City. This complex has a total capacity of 727 MW.
Another hydro-electric power generating facility is that in Maramag, Bukidnon which utilizes the waters of Pulangi river, with a total capacity of 255 MW.
In all, the Agus and Pulangi plants have a combined 982 MW of hydro-electric power generating capacity. But because of the dry spell, the receding level of water inflow has undermined its capacity to produce electricity for the Mindanao grid.
The Agus plants are dependent on water inflow from Lake Lanao which in turn is fed by rivers emanating from the Lanao del Sur and Bukidnon watersheds. The Pulangi River is fed by the watersheds of Bukidnon and Agusan.
The water level in Lake Lanao, as monitored daily has already breached the critical point of 699.15 meters since last week.
According to Pedro Ambos of the Napocor’s Mindanao Generation division, some plant engineers are already reporting the entry of some silt into the turbines.
When the water reaches the 698.15-meter level, Napocor will have to shut down the hydro-power plants to prevent serious damage.
Data provided in the NGCP advisories showed that the lake water is receding at an average of one centimeter a day since Sunday.
At this rate of decline in the water level, it will take three months before the condition for a forced shutdown of the plants will occur. That would be towards June, traditionally the onset of the rainy season.
But within such period, the hydroelectric plants will only be running at less than 15 percent its capacity, almost enough for the estimated 150-megawatt needs of the Zamboanga Peninsula.
Table 5: Water Level of Lake Lanao
| Date | Water level (meters) | Decrease (in meters) |
| Feb28 | 699.08 | -- |
| March 1 | 699.07 | 0.01 |
| March 2 | 699.06 | 0.01 |
Mindanao has 19 existing power plants with a total installed capacity of 1,953.9 megawatts. Of this, total dependable capacity is at 1,672.1 megawatts comprising of diesel-fed, 493.4 MW; geothermal, 101.3 MW; hydro, 876.4 MW; solar, 1.0 MW; and coal thermal, 200 MW.
Eleven of these 19 plants are embedded generators for distribution utilities or large power users. The 11 plants have a combined rated capacity of 156.6 MW, or total dependable capacity of 122.4 MW. This leaves eight plants providing for the entire Mindanao grid, at total dependable capacity of 1,549.7 MW.
An additional hydroelectric generating capacity of 26 MW is expected on April and another 16 MW on May this year.
Failing Mindanao
The current power crisis is a reflection of the failure of the Department of Energy’s Power Development Plan (PDP) to respond to Mindanao’s power needs.
A 2006 Update Supplement of the PDP showed that energy consumption was estimated to increase at an annual average of 6.7 percent in Mindanao. Expected peak demand was determined along this projection.
Table 6: Projected Peak Demand
| Year | Peak Demand (in MW) |
| 2006 | 1,293 |
| 2007 | 1,363 |
| 2008 | 1,440 |
| 2009 | 1,525 |
| 2010 | 1,620 |
But actual power demand was a bit lower. The DOE’s 2008 Power Statistics said this could be a result of the downtrend in production activities between 2007 and 2008 because of the global recession.
Table 7: Actual Peak Demand
| Year | Peak Demand (in MW) |
| 2006 | 1,228 |
| 2007 | 1,241 |
| 2008 | 1,204 |
| 2009 | - |
| 2010 | - |
The PDP noted that by end 2006, “the aggregate dependable capacity, including the embedded generating units of private distribution utilities is estimated at 1,492 MW.”
With current dependable capacity of 1,672.1 megawatts, this means that 180.1 megawatts dependable generating capacity was added in Mindanao in the last three years.
The PDP projected that in the next 10 years from end of 2006, the required capacity will increase to 2,556 MW. With the 210-MW Mindanao Coal-fired Power Plant on-stream by the end of 2006, the PDP outlined some 850 MW indicative power projects to prepare for the expected rise in power demand.
These consist of at least 100-MW plants to be available yearly from 2009 to 2014. These capacity additions were estimated in 2006 to require some P 99.5 billion.
Despite setbacks in the timing of these projects, the PDP’s 2006 Update still expected the 210-megawatt coal-fired plant to contribute largely to “stabilize the power supply in Mindanao for the next two years,” meaning for 2007 through 2008. This is why no capacity additions were recommended within these periods.
It is quite notable that the peak load demand in the afternoon of March 2 of 1,400 megawatts is already within range of the PDP’s peak demand projection for 2008, that is, 1,440 megawatts.
This means that Mindanao’s current power demand situation is comfortably within the planned level of generation capacities.
What the PDP seems to have missed is factoring in various scenarios of impact of a long dry spell. Ryan D. Rosauro, Inquirer Mindanao
