The electricity mix of Panama (PA) is normally quoted as a single figure per month. For July 2026 there are two, published by the same system operator and uploaded on the same day: 1,145,826.22 MWh and 1,133,530.81 MWh. Neither is an error, and neither publication explains how its base differs.
How the electricity mix of Panama gets quoted
The figure travels in compact form: a percentage of hydro generation, another of thermal, another of solar, and the set is presented as the composition of the month. That figure then enters scope 2 reports, sustainability statements and supply contract clauses, almost always without naming the document it came from.
The national dispatch centre describes itself as a non-profit unit of the state transmission company that coordinates the operations and transactions among wholesale market participants. It is the primary source of the mix, and it publishes both documents in the same market reports section.
Where the exposure sits: two totals for the same month
The Monthly Wholesale Market Report for July 2026, dated 17 August 2026, states that total generation was 1,133,530.81 MWh and splits that total into six slices. The Monthly Generation Report, a spreadsheet with one column per plant, closes the same month at 1,145,826.22 MWh and carries the note «Medición del Sistema Scada».
| Item for July 2026 | Monthly Generation Report | Monthly Market Report |
|---|---|---|
| Total generation, MWh | 1,145,826.22 | 1,133,530.81 |
| Hydro | 38.48% | 38.42% |
| Thermal | 36.79% | 36.31% |
| Solar | 10.52% | 10.88% |
| Wind | 7.59% | 7.66% |
| Self-generation | 6.61% | 6.72% |
| Status of the data | SCADA metering by plant | monthly market report |
The difference between the two totals is 12,295.41 MWh, or 1.07% of the larger one. Because each publication calculates its percentages against its own total, the difference passes through to every share: solar appears at 10.52% in one document and at 10.88% in the other, for the same month and the same operator.
The precedent: four consecutive months with the same gap
The distance between the two series is not a July incident. The monthly market reports for April, May and June 2026 each close below the generation file, with a gap moving between half a point and slightly more than one. The pattern is stable in sign and variable in size.
| Month of 2026 | Monthly Generation, MWh | Market Report, MWh | Gap |
|---|---|---|---|
| April | 1,205,067.11 | 1,197,369.14 | 0.64% |
| May | 1,269,823.04 | 1,258,432.46 | 0.90% |
| June | 1,192,775.80 | 1,177,650.73 | 1.27% |
| July | 1,145,826.22 | 1,133,530.81 | 1.07% |
The July market report also records consumption of 1,101,320.46 MWh and transmission losses of 32,210.35 MWh, equal to 2.84% of the net total generation of the system according to its own text. That is a third level of the same month, and its denominator does not match either of the previous two.
What moves when the base changes
The renewable share of July 2026 admits three defensible readings, depending on what goes into the denominator. All three use the same criterion in the numerator — hydro plus solar plus wind — and all three come from documents of the system operator. The distance between the first and the third is four percentage points.
| Calculation base | Denominator, MWh | Renewable |
|---|---|---|
| Total generation, generation file | 1,145,826.22 | 56.60% |
| Total generation, market report | 1,133,530.81 | 56.96% |
| Generation less self-generation | 1,070,059.24 | 60.60% |
One base must never be subtracted from the other. Taking the numerator from one publication and the denominator from another produces a figure that exists in neither document, and that cannot be reproduced later by anyone trying to verify it. The operator’s statistics section does not arbitrate between them either.
How this is covered in a contract or a report
The cover is documentary and fits in one line. Every time an electricity mix figure enters a supply contract, a certificate or a corporate statement, the full reference includes four elements: the exact name of the publication, the month of the series, the date on which the figure was taken, and whether the base includes or excludes self-generation.
The operator itself asks for this in the footer of its site, where it invokes Law N° 6 of 1997 in making the information available and warns that its use must cite the source, and that the information may be updated to correct errors or inaccuracies. In other words: later revision is anticipated by the publisher, and a citation without a cut-off date has no defence once the series moves.
What is worth watching over the coming months is concrete. Market reports come out around the 15th to the 17th of the following month and the generation file is refreshed in the same batch, so August 2026 will show whether the gap follows the pattern. The operations reports section additionally carries the daily reports and the post-dispatch files, which is the level where a revision would show up first.
Two further indicators from the same month deserve tracking because they hit cost before composition: forced generation in July 2026 was 39,690.87 MWh with an excess cost of B/. 2,726,223.64, and the weighted average marginal cost of the month was B/.76.42/MWh against B/.105.65/MWh in June. Sector policy is followed separately, at the national energy secretariat, which does not publish these series.
Analysis, not personalised advice. For transactional decisions, verify the tariff value or the text of the rule directly with the operator or the regulator.