What the recommendation depends on

Nine conditions, rated on how likely each is to hold.

Thai biomethane may be transported to and injected into the Malaysian system, at a Thai charge at or below $1.50/MMBtu, which is the level that still clears the 13% bar; the project falls to the 8% floor at $2.87. Long shot, and weaker than an unpriced tariff. The segment that matters is owned by a 50/50 PTT and PETRONAS project company serving only its two shareholders, so what is missing is an access regime rather than a published rate, and the two parties who would grant it sell the gas this project displaces. The interconnection exists and PETRONAS Gas lists Thailand as an entry point, but no precedent for cross-border biomethane on this path was found and the Thai tariff is unpublished. This is a testable hypothesis: a written position from PTT and from PETRONAS Gas settles it, and the recommendation must not assume it resolves favorably.

Enough mills will contract. Plausible for the 100 tonne first phase, which needs about 20 mills against 42 in the South with digesters. A long shot for the 200 tonne target, which needs 41. Testable by a counted census and term sheets.

The $20 price is available to a Thai supplier. Plausible. Regional benchmarks bracket it, but the sandbox allocates to generators, the first physical deal has gone to a Malaysian supplier, and the February 2026 award is unpublished. Testable by a term sheet.

Upgrading capital is nearer the client's figure than the Western benchmark. Plausible, and it is the highest-value cheap test in the plan: three vendor quotations move the return by roughly 13 percentage points.

Feedstock can be contracted at or below 4.83 THB/Nm3. Plausible. That price is still 2.22 times what a mill nets from burning the same gas under the current biogas feed-in tariff. It is the most movable of the three levers.

Thai palm oil mill effluent biomethane meets Singapore's carbon-intensity and certification threshold. The brief calls this a binary condition and it is: if it fails, there is no export business at any price. We could not establish where the threshold sits. The regulator's own release announcing the sandbox states no carbon-intensity figure and no certification requirement, and we found none published elsewhere. What is known is that palm oil mill effluent qualifies under the European renewable energy directive's Annex IX Part A and that Gas Malaysia's Kluang station is certified under the scheme that governs it, so a Malaysian producer of the same molecule is certified today. The condition is therefore likely rather than assured, and it is not settled here: only the counterparty and the scheme can settle it. It is listed here because a binary condition disclosed in a regulatory section and omitted from the conditions list is not disclosed where a board reads.

Four mills can be reached by one gathering line. Plausible where mills cluster around Surat Thani and Krabi, a long shot at the corridor's edges. This is a testable hypothesis and the mill census settles it: if clusters do not form, capital rises from $15.63M to $25.08M and the return falls to 11.1%, below the Go bar.

The hub runs about 280 effective days a year. Plausible. That is 330 operating days at 85% feedstock availability, and both figures are estimates: we searched for a Thai monthly fresh-fruit-bunch series and did not find one in a form we could use, so the seasonal profile behind the second number is inferred rather than measured. The band matters more than the point. At 300 days and 75% availability the return is 12.6%, just under the Go bar; at 346 days and 95% it is 19.3%, well above it. Two metered mills across a full season would close most of that spread, and it is the cheapest remaining test in the plan.

The buyer contracts take-or-pay at or above 89%. Long shot. The brief's own indicative terms say about 60%, and at 60% this project returns 2.8%, below the No-Go floor. Nothing in the sources establishes what the sandbox's allocated generators are offering, and a buyer in a market where regional supply is building faster than demand has no reason to offer a full take. This is a testable hypothesis, settled by a term sheet, and it is the condition most likely to fail.

Twenty figures in this analysis are judgment rather than measurement, and a reader should know which. Seventeen carry no external source at all; three more cite a document that states a related fact rather than the figure itself. They are the plant's operating days and the seasonal availability of feedstock; the number of mills a cluster reaches and the length of its gathering line; the working capacity of desulfurization media; the utilization at which pipeline capacity is booked; all-in truck cost as a multiple of fuel, the trips a trailer makes in a day, the spare ratio on the fleet and the cost of a prime mover; the export terminal, injection station, container handling and certification charges; the carbon dioxide netback and the discount on its plant cost against a liquefaction train; a tank container's payload; the first-year ramp; the size of the cost stress; and the operations contractor margin. Each is declared as an estimate in the figures manifest with the reasoning behind it, and a further three figures that do carry a source rest on estimated distances: the collection radius, the road distance to Johor and the road distance to Muar.

Three of the fifteen move the answer. The truck-cost multiple sets a collection line worth $1.51/MMBtu, or more than a quarter of the margin. The certification charge is unbounded until a scheme has quoted it. And the carbon dioxide netback decides whether a co-product worth more than the entire gap to the hurdle is worth building a plant for.

Two inputs that are sourced rather than estimated were nonetheless taken at one point of a published range, and both run against this memo's own conclusion, so they are moved here rather than left. Upgrading power is taken at 0.25 kWh/Nm3, the midpoint of a published 0.2 to 0.3 band; at the top of the band it costs $1.70/MMBtu instead of $1.42. And the methane fraction is taken at the workbook's 55% while the measured industrial value is 60.5%; at the measured figure the feedstock line falls from $6.22 to $5.66/MMBtu, worth 0.56 against a price-floor gap of $1.42. The richer gas is the larger of the two effects and it favors the project. Neither is adopted, because one is a design assumption the client has made and the other is a single plant's measurement in another country, but a reader should know that the uncertainty in inputs nobody varied is of the same size as the margins the verdict turns on.

The 16.3% books two of these conditions, and it should be read that way. It assumes the pipeline is available, which the first condition has not established, and it assumes the buyer lifts full nameplate, which the brief's own indicative 60% take does not oblige. Both are rated long shots above. So 16.3% is the top of a range whose bottom, at 60% take, is 2.8% and below the No-Go floor, and if the pipeline condition fails outright the remaining route returns minus 5.2%. The figure reported at full nameplate is the client's own basis and the only one on which the brief's criteria can be scored against their work; it is not the expected outcome, and nothing here should be read as saying it is.