How biomass supply shifts in the rainy season, and how to stock for it

Plants that plan fuel stock from dry-season figures hit the same problem every year: more fuel consumed for the same steam once the rain arrives.

Photo: Halanna Halila on Unsplash

Three things that change

Feedstock moisture rises. Wood felled and piled in the field during the rains takes water back up, so calorific value per kilogram falls.

Field access worsens. Dirt tracks through plantations turn to mud, extraction slows, and some blocks are unreachable for spells.

The pile at your plant gets wetter too. An uncovered yard with poor drainage will re-wet fuel that arrived dry.

What follows in practice

Higher moisture means more fuel fed for the same steam. Budget from weight alone without adjusting for calorific value and the number will overrun.

And because moisture swings more than usual, operators adjust more often, so furnace temperature is less steady than in the dry months.

How to plan

Build stock before the season. If you normally hold seven days, plan for ten to fourteen to cover spells when trucks cannot reach the plantations.

Adjust the yard. Raise the base for drainage. A roof over the portion due to burn within a week or two helps considerably.

Rotate properly. Burn oldest first; do not let an old pile sit at the back of the yard until it rots.

Agree seasonal specification with the supplier. A straight supplier will tell you in advance when moisture will rise, rather than shipping it and letting you discover it.

Consider blending pellets. Some plants blend pellets through the wet months to pull average moisture down, then return to chips alone in the dry season.

What belongs in the contract

• Acceptable moisture range, stated by season where possible
• What happens when moisture exceeds it
• Guaranteed minimum monthly volume during the rains
• Weighing method and location

The last matters more in the wet season, because the weighbridge counts the water that came with the load.

Ask us directly

We produce in Trang and know how local supply moves through the year. If you are planning next year's stock, call and we will tell you what to allow for and when. +66 92 392 2292.