By WoodPelletCN · Published and revised · Business contact: Jasmine Li
Net and gross calorific value
GCV includes heat associated with condensing water vapour. NCV excludes that contribution. Do not compare a supplier’s GCV directly with another supplier’s NCV, or insert GCV into a calculator that asks for NCV.
Keep the moisture basis visible
As-received results describe fuel with its delivered moisture. Dry-basis results describe fuel excluding moisture. Ask the laboratory for the appropriate result; do not apply a second moisture deduction to an as-received NCV.
What to request
Request the sample date, batch reference, test method, result in MJ/kg and stated basis. A result without a traceable sample cannot establish the performance of the shipment being quoted.
Worked example
At an illustrative landed price of USD 150/t and an as-received NCV of 15 MJ/kg, fuel energy costs USD 10/GJ. At an assumed 80% useful-heat efficiency, the cost is USD 12.50/GJ. These are demonstration values, not a product specification.
Four labels that change the comparison
| Report label | Meaning for your buying brief |
|---|---|
| GCV / higher heating value | Includes the water-condensation contribution under its stated test conditions. Keep separate from NCV. |
| NCV / lower heating value | Use the reported as-received NCV for this website’s fuel-cost tools. |
| As received | Includes moisture in the sampled fuel. Do not deduct that moisture again. |
| Dry basis | Describes a different basis. Request a laboratory conversion with the required composition data; changing units is not a basis conversion. |
Turn the example into a purchasing decision
The demonstration calculation is 150 ÷ 15 = 10 USD/GJ of fuel input, then 10 ÷ 0.80 = 12.50 USD/GJ of useful heat. Multiplying by 3.6 gives 45 USD/MWh of useful heat. This excludes equipment, maintenance and ash disposal.
For two offers, enter each delivered price, each as-received NCV and each applicable efficiency separately. The cheaper tonne can be the more expensive useful heat. An assumed efficiency should remain marked as an assumption until your equipment team supports it.
Copy these questions into your enquiry
- Does the quoted value mean NCV or GCV, and on what moisture basis?
- Which sample and test date does it describe, and does it represent the proposed supply?
- Does the delivered price include the same freight, tax and unloading items as the comparison fuel?
- What efficiency basis is used by the equipment provider?
Sources and scope
Official references below explain the relevant method or scope. Our purchasing worksheets and illustrative calculations are not batch results, certification or equipment approval.
Your next purchasing step
Review the wood pellet quotation checklist and compare two fuels at equal useful heat.