WESM Monthly Price Tracker: system and grid average spot prices, supply, demand and margin, January 2025 to July 2026

Key findings

1. As published by IEMOP, the system-wide average market price was 8.31 PHP per kWh in the July 2026 billing month, after 9.54 in June 2026 and 7.79 in May 2026. IEMOP attributed the July easing to improved conditions in the Visayas, seasonally lower demand and improved HVDC flows.
2. Across the nineteen billing months the highest system price in this window was June 2026 (9.54) and the lowest February 2025 (2.73); the highest grid price was the Visayas in June 2026 (14.32, revised by IEMOP from a first-published 14.46). These are extremes of the window only (Signal Trackers computation).
3. The system price rose from 2.96 in the January 2025 billing month to 8.31 in the July 2026 billing month, a change of 5.35 PHP per kWh or about 181 percent between those two months (Signal Trackers computation). The endpoints matter: IEMOP called January 2025 the lowest average since January 2023, and July 2026 follows a market suspension and interventions.
4. The unweighted mean of IEMOP's monthly system averages was about 4.00 for the twelve 2025 billing months, 3.92 for January to July 2025 and 6.09 for January to July 2026, the last including April 2026 at 5.63 under Modified Administered Prices (Signal Trackers computations). IEMOP's own first-half 2025 average, on its own basis, is 4.14 PHP per kWh; the two are different measures.
5. The Visayas monthly price was above Luzon's in 15 of the 19 months and Mindanao's was above Luzon's in 12 of 19 (April 2026, when all three grids and the system printed 5.63 under Modified Administered Prices, counts as not above). In June 2026 the Visayas price exceeded Luzon's by 6.37 PHP per kWh (Signal Trackers computations).
6. According to IEMOP, the ERC suspended the market from 26 March to 30 April 2026 after the declaration of a State of National Energy Emergency, applying Modified Administered Prices with coal settled at 6.00 PHP per kWh; normal clearing resumed on 1 May 2026. The May and June 2026 rises came, in IEMOP's account, with higher summer demand, plant outages, grid alerts, reserve deficiencies and HVDC transfer limits into the Visayas.
7. The largest month-on-month system moves in the window were March 2025 (+2.61), May 2026 (+2.16), June 2026 (+1.75), September 2025 (-1.55), October 2025 (+1.50), April 2026 (+1.32, a Modified Administered Prices month) and July 2026 (-1.23). The highest system average demand was May 2026 (15,755 MW) and the lowest system margin July 2026 (3,590 MW); the highest margin was February 2025 (5,725 MW). Signal Trackers computations from IEMOP's tables.

System table, January 2025 to July 2026 billing months

Every figure is as printed in IEMOP's Monthly Market Operations Highlights for that billing month (the latest report where a month appears in more than one). Margin follows the report definition: supply minus (demand plus reserve requirement), with HVDC flows entering only the grid tables. The price bar runs from 0 to 15 PHP per kWh.

Source for every row: IEMOP, Market Operations Highlights for the named billing month (see Sources). Revised values are marked; the earlier value is listed under Revisions.

Grid selector: supply, demand, reserve, margin and price by grid

Choose a grid to see its full monthly table. Grid margins include HVDC flows, per IEMOP's printed definition. The grid "average price" is the report's load weighted average price (LWAP). Without JavaScript, the Luzon table is shown here, the Visayas and Mindanao tables are in the disclosures below, and the system table is in the section above.

Source for every grid row: IEMOP, Market Operations Highlights for the named billing month, from the 2025 and 2026 listing pages (see Sources). Revised values are marked and listed under Revisions.

Both static tables: IEMOP, Market Operations Highlights for the named billing month, via the 2025 and 2026 listing pages.

What IEMOP said drove the market

These are IEMOP's own attributions, taken from its public news releases for the months it covered. They are the market operator's account, not an independent finding by Signal Trackers, and the ERC orders and emergency declaration behind them were not retrieved.

2026

March 2026 billing month (release of 8 April 2026)

IEMOP reported that system-wide average supply decreased to 19,913 MW, a 0.4 percent decline from February 2026, while average demand increased to 13,383 MW, 4.0 percent higher, and that these levels resulted in a tighter system supply margin of 4,654 MW compared with 5,283 MW in February. IEMOP attributed the declines in the Luzon, Visayas and Mindanao supply margins (576 MW, 8 MW and 46 MW) to higher outage levels and variations in HVDC flows, and said these conditions led to an increase in the system-wide average market price to 4.31 PHP per kWh from 3.50 in February.

April 2026 (release of 13 May 2026)

According to IEMOP, in response to the declaration of a State of National Energy Emergency and fuel conservation and prioritisation measures in the power sector, the ERC declared a Market Suspension effective 0005H on 26 March 2026. Under Modified Administered Prices, coal-fired facilities were settled at a fixed 6.00 PHP per kWh and negative administered prices were set to zero. The April 2026 load price was uniform across all regions at 5.63 PHP per kWh, while generation average prices were 5.13 (Luzon), 5.32 (Visayas) and 5.50 (Mindanao). On 30 April 2026 the ERC declared the resumption of normal clearing and settlement effective 1 May 2026 at interval 0005H.

May 2026 (release of 10 June 2026)

IEMOP cited higher summer demand (system average demand 15,755 MW, up 9.4 percent), plant outages and grid alerts. Administered Pricing applied for 20.37 percent of the time in Luzon, 19.75 in the Visayas and 16.67 in Mindanao, covering the part of the suspension that fell inside the billing month (26 to 30 April 2026) and interventions due to manual load dropping. IEMOP also reported that throughout the 26 April to 25 May 2026 billing period the Leyte-Luzon HVDC facility was either operating at its maximum Luzon-to-Visayas transfer limit of 250 MW or at a security-limited transfer level for 46.06 percent of the period, higher than the 25.90 percent observed in April 2026.

June 2026 (release of 9 July 2026)

IEMOP cited localised supply tightness and reserve deficiencies that produced Constraint Violation Costs in real-time prices, multiple yellow and red alerts in the Visayas, forced outages of several large units, and the Leyte-Luzon HVDC at its limit or security-limited for 67.46 percent of the period. Sustained high prices triggered the Secondary Price Cap under a cumulative price threshold of 12.413 PHP per kWh, capped at 7.423. The release quoted the system price as 9.56; the July 2026 report revised it to 9.54.

July 2026 (release of 6 August 2026)

IEMOP reported that improved conditions in the Visayas, seasonally lower demand in the rainy season and improved HVDC flows eased prices across the three grids, and stated that the system-wide average market price dropped by 13.1 percent, from 9.54 in June 2026 to 8.31 in July 2026. The 13.1 percent is IEMOP's own figure; 9.54 to 8.31 is a fall of 12.9 percent, and 13.1 percent reconciles with 9.56, the June 2026 price as first published and later revised to 9.54.

2025

January 2025 (release of 11 February 2025)

IEMOP described the 2.96 system price as the lowest average price recorded since January 2023, with a relatively high supply margin after low demand in cooler weather. The release quoted an "average system margin" of 7,581 MW, which is supply minus demand; the report table's margin of 5,651 MW also subtracts the 1,930 MW reserve requirement. Both definitions are IEMOP's; this tracker uses the table definition.

April 2025 (release of 6 May 2025)

IEMOP reported that overall power supply rose to 21,345 MW, an 8.8 percent increase from March 2025, and that demand rose to 14,739 MW, about 7.8 percent higher, which IEMOP attributed largely to intense summer heat. IEMOP reported that the supply margin widened to 4,585 MW compared with 3,957 MW in March, and that market prices fell from 5.34 to 4.52 PHP per kWh, which IEMOP described as a 15.3 percent decrease.

First half of 2025 (release of 24 July 2025)

IEMOP stated that WESM prices averaged 4.14 PHP per kWh in the first half of 2025 against 5.58 in 2024, a 26 percent decline and, in its words, the most affordable average since 2020, citing improved supply margins, renewable energy investment and transmission enhancements. These are IEMOP's figures on its own basis.

September 2025 (release of 7 October 2025)

IEMOP described the 3.04 system price as the lowest in seven months, with a wider margin, no major unplanned outages and rainy-season hydropower output.

December 2025 (release of 28 January 2026)

IEMOP reported that Luzon supply continued to increase while demand declined, reducing the Luzon average market price to 2.98 PHP per kWh from 3.52, while supply margins in the Visayas and Mindanao declined by 136 MW and 245 MW on planned and forced outages. IEMOP said these tighter regional conditions, combined with transmission constraints that limited access to lower-cost generation in Luzon, contributed to an increase in the system-wide average energy price to 4.38 from 3.98. In the same release IEMOP reported that the system-wide supply margin nonetheless widened, to 4,798 MW from 4,572 MW in November 2025.

Definitions used on this page

Billing month

IEMOP's billing month runs from the 26th of the previous calendar month to the 25th. "July 2026" is 26 June 2026 to 25 July 2026. Every month label on this page is a billing month, not a calendar month.

Average price

For the grids, the report's load weighted average price (LWAP) in PHP per kWh. For the system, IEMOP's "system-wide average market price"; its basis is not printed on the table page, and it is not the Effective Spot Settlement Price, which IEMOP reports separately. The reports note that intervals are applied with a Secondary Price Cap, and prices in several months reflect Administered Pricing, the Price Substitution Methodology and the Secondary Price Cap.

Margin

As printed in the reports: margin = supply minus (demand plus reserve requirement), plus or minus HVDC flows for the grid tables. The reserve requirement comprises regulating, contingency and dispatchable reserve. IEMOP's news releases sometimes quote a simpler supply-minus-demand margin (7,581 MW for January 2025 at system level); both are IEMOP definitions.

Modified Administered Prices (ModAP)

The pricing applied during the ERC market suspension of 26 March to 30 April 2026, as described by IEMOP: coal settled at 6.00 PHP per kWh and negative administered prices set to zero. The identical 5.63 across all grids and the system in April 2026 is an administered outcome, not a market convergence.

Revisions recorded across reports

Each report tabulates the last three billing months, so most months appear in three reports. Signal Trackers compared every value across the overlapping reports. All agreed except the following, where the later report is used:

• June 2026 system average price: 9.56 PHP per kWh in the June 2026 report (published 9 July 2026) and in IEMOP's 9 July 2026 news release; 9.54 in the July 2026 report (published 6 August 2026).
• June 2026 Visayas average price: 14.46 in the June 2026 report and the 9 July 2026 release; 14.32 in the July 2026 report.
• July 2025 grid margins, 1 MW rounding differences: Luzon 3,469 in the July 2025 report, 3,468 in the August and September 2025 reports; Visayas 348 then 349; Mindanao 1,126 then 1,125.

Sources

1. IEMOP (Independent Electricity Market Operator of the Philippines). Monthly Market Operations Highlights, one report for each billing month from January 2025 to July 2026 (nineteen reports, published 17 February 2025 to 6 August 2026 per IEMOP's listing). Operational Highlights tables for the System, Luzon, Visayas and Mindanao. Listing pages: 2025 Market Operations Highlights and 2026 Market Operations Highlights. Retrieved 6 September 2026. The May, June and July 2026 reports carry an all-rights-reserved notice; this tracker publishes numerical facts and short attributed statements only and reproduces no page, chart or slide.
2. IEMOP news releases on monthly market prices, 11 February 2025 to 6 August 2026 (ten releases), from IEMOP News, for example "July 2026 WESM prices ease as Visayas market conditions improve" (6 August 2026). Retrieved 6 September 2026. Used for IEMOP's stated drivers and as corroboration of headline figures for the months the releases cover.

Signal Trackers is a publisher on DropRegion. This tracker is not authorised by, affiliated with or endorsed by IEMOP.

Methodology

Signal Trackers downloaded the nineteen report PDFs from IEMOP's market reports pages, extracted their text, and parsed the Operational Highlights tables for the system and each grid into a structured series. Because each report shows the last three billing months, each month was compared across every report that contains it; the latest report's value is published and any earlier differing value is listed under Revisions. The series was re-parsed independently in a verification pass; all 76 month-and-grid rows matched.

Month-on-month changes, extremes, counts, gaps and means are Signal Trackers computations on IEMOP's published monthly averages. Means are unweighted arithmetic means of monthly averages, not load-weighted period averages, which is why they differ from IEMOP's own period figures. April 2026, a Modified Administered Prices month, is kept in the means and counts because it is a published billing-month value that market participants were settled on; it is flagged wherever it enters a comparison so readers can set it aside. Drivers are quoted or closely paraphrased from IEMOP's news releases and attributed to IEMOP throughout.

Limitations

• Nineteen-month window, January 2025 to July 2026 billing months. "Highest" and "lowest" refer to this window only; the only longer comparisons are IEMOP's own attributed statements.
• Billing months, not calendar months.
• The basis of the system "average price" is not printed on the table page; grid prices are load weighted average prices.
• Means are unweighted Signal Trackers computations and are not IEMOP's period averages.
• Published prices include intervals under Administered Pricing, the Price Substitution Methodology and the Secondary Price Cap; April 2026 was entirely under Modified Administered Prices.
• The ERC orders, the emergency declaration and the Executive Order referred to by IEMOP were not retrieved; drivers are IEMOP's attributions.
• Wholesale only. Nothing here supports any statement about consumer bills, distribution utility generation charges or pass-through to retail rates.
• IEMOP's news releases corroborate headline figures for most but not all months; the primary evidence for every row is the report itself.

Freshness

Freshness class F2 (monthly). Checked and verified 6 September 2026 against all nineteen reports. IEMOP has published each report between the 3rd and the 22nd of the month after the billing month ends; the August 2026 report is expected in September 2026. A new report adds one row and may revise the previous month. Checking a source is not the same as changing this Drop; the version panel records changes.

Version

v1.1, 6 September 2026: seven corrections from the first evaluation (drivers rebuilt from the verified register, including the note on IEMOP's 13.1 percent July 2026 figure; April 2026 flagged in the mean and the moves list; revision markers limited to price revisions in the system table; source notes on the grid tables; methodology note on April 2026; marker contrast and live region; grid intro wording). No published figure changed.

v1, 6 September 2026: first evaluated version. Drop ID D-20260906-f204. Corrections and later versions will be listed here.