The Philippines' Department of Energy will issue revised guidelines in October for its coal block auctions, aiming to reinforce baseload power generation and determine the future operation of the country's largest open-pit coal mine, Energy Secretary Sharon Garin said on September 22.

The government scrapped the initial tender last week to reassess contract parameters and address industry feedback. Garin said the new round would cover the same sites, including the Semirara Island, but under new rules, with a central objective of ensuring output from major deposits is prioritized for domestic power generation.

"We want to make sure that the mining of coal in Semirara is maximized and optimized," Garin said. "It is not only the extraction that is important. We also need to optimize where the coal is used in the Philippines."

Because the technical specifications of some domestic plants prevent them from using raw Semirara coal without modification, the DOE is evaluating a dedicated coal-blending facility to process domestic output to meet local plant standards, reducing reliance on imports.

Garin has previously noted that the Philippines sources about 95% of its coal from Indonesia and that blending could allow greater use of local supply.

The secretary noted that the updated framework will set clearer financial returns, verifiable public benefits and firm commitments from developers on domestic supply utilization.

Alongside the primary Semirara deposit, the tender will offer exploration and development rights for eight additional blocks in Cagayan and Isabela provinces.

The push for long-term fuel supply comes amid fresh grid disruptions. Unplanned outages in Iloilo and Cebu triggered yellow and red alerts across the Visayas grid, signaling tight reserve margins. Garin said the department is rushing power barges into service within 2026 or early 2027, describing the repeated alerts as frustrating.