Build the feedstock plan around the calendar

Map supply before fixing the plant recipe

A plant consumes feed throughout its operating year, while many agricultural materials arrive in a short season. An annual availability total hides that mismatch. Start with a month-by-month view of generation or harvest, likely collection, competing demand and the material's condition at delivery.

For a mixed-feed plant, each material needs its own calendar. A factory by-product, a forage crop and baled residue do not have the same supply risks. The fallback plan should identify what can replace a missing material and what technical review is required before changing the recipe.

Calculate usable inventory

Worked example: a hypothetical plant consuming 80 wet tonnes/day needs 4,800 wet tonnes for a 60-day interruption before losses and reserves. If a justified planning allowance assumes 8% quantity loss over storage, the opening inventory required is 4,800 ÷ 0.92 = about 5,217 tonnes. The loss percentage is an illustrative input and must be established for the material and storage method.

Storage volume then depends on the achieved bulk density and usable geometry. Area allowances need access, drainage, handling movement and any separation or fire provisions required by the approved design. Gross bunker dimensions should not be treated as completely usable stock volume.

Protect quality at reception and in storage

Receiving controls should verify supplier, weight, material condition and contamination before unloading. Long fibres, stones, grit, packaging and dilution can create costs well beyond the purchase price. Define who inspects, how samples are retained and what happens to a rejected load.

The storage method should suit the material. Dry baled residues, fresh dung, press mud and ensiled crops need different arrangements. Inventory records should identify receipt date, storage location and condition so that deterioration or recurring supplier problems can be traced.

Include cash and dispatch constraints

Seasonal procurement can create a large cash requirement before gas revenue is earned. Model purchase, transport, handling and stock financing in the actual months when they occur. A project can appear profitable on an annual statement while lacking the cash needed for its supply season.

Daily withdrawal also matters. Loading equipment, preparation hours and stock access must support the feeding schedule during rain, maintenance and delivery peaks. The procurement plan should therefore be reviewed with the layout and operations teams, rather than issued as an independent supplier list.

• Reconcile opening stock, receipts, withdrawals, losses and closing stock.
• Define minimum stock and a trigger for replacement procurement.
• Review quality and delivered cost by supplier and season.
• Test the downside case for simultaneous lower supply and higher price.