The feedstock: what Southern Thailand can actually deliver
An average Southern mill yields about a third of the gas the plan assumes, so the target build needs roughly half of every mill in the South.
Thailand produced 18.6 million tonnes of oil palm in 2024 across 124 crude palm oil mills, and 85.9% of harvested area sits in the South, with Surat Thani, Krabi and Chumphon together holding 57.4% of national plantations (Krungsri Research). Taking the Southern share of area as the Southern share of throughput, and the brief's own count of 70 Southern mills, the average Southern mill processes about 228,286 tonnes of fresh fruit bunch a year.
One tonne of fresh fruit bunch yields about 0.7 m3 of POME (Akademia Baru), and one cubic meter of POME yields 25.7 Nm3 of biogas, measured across 90 industrial records at an operating Malaysian plant, with a standard deviation of 6.6 (Chin et al.). The same paper's default literature value is 28. That chain gives 11,252 Nm3 of biogas a day for an average Southern mill, which is 37.5% of the 30,000 the aggregation concept assumes, and 4.88 tonnes a day of biomethane product.
The consequence runs through the entire plan.
| Per-mill biogas, Nm3/day | Product per mill, t/day | Mills for 100 t/day | Mills for 200 t/day |
|---|---|---|---|
| 30,000 as assumed | 13.00 | 5.9 | 11.8 |
| 20,000 | 8.67 | 8.9 | 17.7 |
| 11,252 as built here | 4.88 | 15.7 | 31.5 |
| 8,000 | 3.47 | 22.1 | 44.3 |
At the figure this analysis builds, the 200 tonne-per-day target needs 31.5 mills. That is 45% of every mill in Southern Thailand and 75% of the 42 that already have a digester, since about 60% of Thai palm oil mills have installed biogas capture (The ASEAN Post). Contracting 32 of 70 independently owned mills on 15-year terms is not a procurement exercise. It is a consolidation of most of an industry, and the plan does not currently describe it as one.
Salerno is further along that road than the arithmetic alone suggests, and the brief says so: it records non-disclosure agreements across 50-plus feedstock partners, a tri-party co-feasibility agreement with a Southern crude palm oil producer, and relationships reaching the national association president. That is the single most relevant asset the case holds against the scale question. What it is not is contracted volume. A non-disclosure agreement establishes that a mill will talk; it does not establish that the mill has a digester, what it yields, whether it is already committed under a power purchase agreement, or what it would charge. Converting 50 signed conversations into 32 signed 15-year supply contracts is the work, and the first-stage census below is the cheapest way to find out how much of it is already done.
The client's own concept states the problem plainly without noticing. Three mills at 30,000 Nm3/day is 90,000 Nm3/day, which on the client's own conversion chain is 39 tonnes a day of product, not the 100-plus the slide claims. The concept is short of its own target by a factor of about three before any correction to the per-mill figure.
Two further constraints on the resource that the plan does not model.
Thai palm milling is seasonal and the industry averaged 37.1% capacity utilization across 2021 to 2023. A hub sized on annual average throughput is short of gas in the low season and spilling it in the peak. We carry a supply availability factor of 0.85 and 330 operating days against the workbook's 346 at constant rate, and we could not find a published Thai mill-level seasonal profile, so that factor is an estimate.
About 40% of Southern mills have no digester. For those, someone must build one before there is any gas to buy, and the client's model carries a biogas unit capital cost of zero.
On whether the mills will sell, the answer follows from what they earn now rather than from what they do now, and it splits the mill base in two. A mill burning biogas in an engine generates about 1.5 kWh per Nm3, and the current feed-in tariff for biogas power projects is THB 2.0724/kWh (Baker McKenzie). That is 3.11 THB/Nm3 gross and about 2.18 THB/Nm3 after the roughly 30% of revenue that generation consumes. The project's offer of 4.00 THB/Nm3 is a 91.3% premium over that, so for a mill on current terms the offer clears comfortably. For a mill on a legacy adder contract it does not, and the Thai government moved in July 2026 to restructure legacy non-firm renewable power purchase agreements, though that policy as announced covers solar and wind rather than biogas. The available pool is therefore mills without a biogas power contract, plus mills whose contract is expiring, and neither the plan nor this analysis yet knows how many of the 70 that is.