BY DAVE SUAN ALBARADO
Rotational brownouts may continue in the province of Bohol as the Visayas power grid struggles with a shortage of available generation capacity, prompting government energy officials and the province’s distribution utilities to coordinate measures to prevent a wider power problem.
Bohol Capitol called a meeting Sept. 10 with major stakeholders in the power sector to discuss the condition of the Visayas Grid and provide residents with accurate information about the continuing electricity problems.
The meeting was led by Vice Gov. Victor Balite Besas on behalf of Gov. Aris Aumentado and attended virtually by officials of the Department of Energy-Visayas Field Office, as well as representatives of Bohol Electric Cooperative I, Bohol Electric Cooperative II, Bohol Light Co. Inc. and Mapalad Power Corp. Also present were the governor’s Chief of Staff, Atty. Filipina Asoy-Piollo, and Provincial Planning and Development Office head Atty. John Titus Vistal.
According to the DOE-Visayas Field Office, the immediate problem is a shortage of generation in the interconnected Visayas-Mindanao power system following the unavailability of several large generating units in Cebu and Iloilo, compounded by the loss of electricity imports from Mindanao.
The resulting shortage has forced the National Grid Corp. of the Philippines (NGCP) to order manual load dropping, or MLD, in portions of the Visayas.
The measure involves temporarily disconnecting selected loads or feeders on a rotating basis to reduce demand and keep the power system within safe operating limits.
For consumers, this means that a brownout in Bohol does not necessarily indicate a problem with a local distribution line or substation.
Rather, some interruptions are being carried out as part of a grid-wide emergency measure directed by NGCP.
Visayas is short of power
The electricity shortage has been building as several major generating units have been unavailable at the same time.
NGCP said the Visayas Grid was placed under a red alert Sept. 10, 2026, with available capacity at about 2,205 megawatts against projected peak demand of 2,460 MW.
The shortage was primarily linked to the unavailability of Therma Visayas Inc. Units 1 and 2 in Toledo, Cebu, and Panay Energy Development Corp. Unit 3 in Iloilo, along with reduced imports from Mindanao.
A red alert is declared when available generation is insufficient to meet consumer demand and the transmission grid’s regulating requirement.
A yellow alert, meanwhile, means the operating margin is insufficient to meet the grid’s contingency requirement.
The situation has not been confined to Bohol.
Distribution utilities across Cebu, Negros, Panay, Leyte and other parts of the Visayas have been implementing or preparing for rotational interruptions when ordered by NGCP.
The problem is also not simply a matter of one power plant going offline.
NGCP reported that 10 Visayas power plants had been on forced outage during September, while other plants had remained unavailable for considerably longer periods.
Several additional generating units were also operating at reduced capacity, contributing to nearly 980 MW of unavailable capacity in the region.
The Energy Regulatory Commission has also been monitoring the prolonged unavailability of major generating units.
Earlier in the year, the ERC and DOE inspected generating facilities following outages that contributed to repeated yellow and red alerts in the Visayas.
Mindanao connection adds to the problem
The Visayas and Mindanao grids are interconnected, allowing electricity to be transferred between the two regions when capacity is available.
But that arrangement has provided less assistance than usual because several Mindanao generating units have also been unavailable.
DOE officials said the loss of Mindanao imports has compounded the shortage in the Visayas.
The department has been working to restore generating units in Mindanao so they can again provide power through the interconnected grid.
Among the units targeted for restoration are Therma South Inc. units in Davao and GN Power Kauswagan Unit 2 in Lanao del Norte.
DOE has said the return of these facilities could improve the amount of power available to the interconnected system.
Bohol among areas affected by manual load dropping
Because Bohol is connected to the Visayas Grid, the province can be included in NGCP’s manual load-dropping instructions when supply becomes critically tight.
The objective is not to keep an area without electricity indefinitely but to distribute the reduction in demand among different portions of the grid.
Recent NGCP-related advisories have included BOHECO I, BOHECO II and Bohol Light Co. Inc. among distribution utilities that may be affected by manual load dropping during periods of insufficient generation.
The interruptions can therefore vary from one locality to another and from one day to the next, depending on the actual power supply, demand and operating condition of the grid.
This also explains why a forecasted brownout schedule can change, be shortened or be canceled when conditions improve.
Power plants expected to return
There is some relief on the horizon.
DOE Secretary Sharon Garin has said several generating units are expected to return to service during September and early October, potentially easing the shortage.
Cebu Energy Development Corp. Unit 1, with about 82 MW, returned to service Sept. 5.
Therma Visayas Unit 1, with about 169 MW, is targeted to return Sept. 15, 2026, while Therma South Unit 1, with 150 MW, is targeted for Sept. 19. GN Power Kauswagan Unit 2, with 103 MW, is targeted for Sept. 20, 2026.
Panay Energy Development Corp. Unit 3, with about 150 MW, is expected to return in early October.
DOE officials have said the restoration of these units should progressively improve the supply situation, although the timing of actual restoration remains dependent on the condition and readiness of each generating facility.
Battery storage seen as additional buffer
The government is also pursuing battery energy storage as a faster-response source of reserve power.
DOE is working with power companies and NGCP to connect 253 MW of battery energy storage capacity in strategic areas of the Visayas — about 50 MW in Panay, 100 MW in Negros, 40 MW in Leyte and 63 MW in Cebu.
Unlike conventional power plants, battery systems can respond rapidly when a generating unit trips or when electricity demand suddenly rises.
DOE said some facilities are already capable of providing support, while efforts continue to accelerate their connection to the grid.
The department has also been pursuing other interim measures, including power barges and generator sets.
The need for additional reserve power has become increasingly important because the Visayas has repeatedly operated with very thin reserves.
NGCP data cited by the Philippine Information Agency showed that the Visayas Grid recorded 96 yellow alerts and 33 red alerts from Jan. 1 through Sept. 7, underscoring how frequently the system has operated close to its limits this year.
Electricity prices
The tight supply situation has also affected electricity prices in the wholesale electricity spot market.
The Independent Electricity Market Operator of the Philippines said the average WESM price in the Visayas rose to P18.59 per kilowatt-hour in August from P11.29 per kWh in July, as generating-unit outages, tighter supply margins and transmission constraints increased reliance on more expensive generation.
The Mindanao average also increased to P19.56 per kWh from P10.39 per kWh during the same period.
The Energy Regulatory Commission has separately ordered the regional implementation of the secondary price cap for the Visayas and Mindanao grids, retroactive to the August 2026 billing period, as part of measures related to the tight market conditions.
For Bohol consumers, the key distinction is that manual load dropping is a grid-stability measure, not necessarily a local distribution failure. The duration and location of interruptions can change depending on NGCP’s instructions and the real-time balance between electricity supply and demand.
DOE has said the immediate priority is to restore unavailable generating capacity, mobilize power that can be imported from Mindanao, connect additional battery storage and strengthen the reserve capacity needed to prevent a repeat of the current crisis.
Until sufficient generation and reserves return, however, rotational brownouts remain possible in Bohol and other parts of the Visayas, particularly during periods of peak demand.
For that reason, authorities are treating controlled, temporary interruptions as preferable to an uncontrolled and potentially much wider grid failure.