Sourcing biogas generating sets from China

Duty on biogas generating sets

Heading 8502 covers electric generating sets and rotary converters. This guide focuses on complete biogas generating sets with spark-ignition piston engines. The selected lines distinguish sets by electrical output in kVA. Give your customs broker the engine specification and alternator rating; a different engine arrangement needs its own classification check. For Stirling-engine equipment, see our Stirling generating set sourcing guide.

Read from the UK Trade Tariff on 1 October 2026, all selected lines carried 0% duty for goods from China. The supplied tariff record lists no anti-dumping or countervailing duty, suspensions or attached import controls for these lines. Import VAT is separate from customs duty.

Confirm the commodity code against the complete machine being shipped. For the wider gas-engine product family and heat-recovery arrangements, see gas CHP generating sets. For LPG-powered equipment, see sourcing LPG generating sets.

Specify the biogas before the engine

Send the factory a gas analysis and the expected variation in methane content, calorific value, hydrogen sulphide, moisture and siloxanes. Ask it to state acceptable fuel conditions at the engine inlet, including pressure and temperature. Agree who supplies gas cleaning, drying, filtration and pressure regulation, and record where the factory's scope ends.

Specify sustained electrical output on that gas, auxiliary power consumption, voltage, frequency, load changes and cooling conditions. If recovering heat, define useful heat output, water temperatures, flow and exhaust back pressure. Ask for a performance test using representative fuel, with gas conditions recorded alongside electrical output.

For sale in Great Britain, machinery needs the relevant conformity assessment and marking. Ask for the declaration of conformity, operating instructions and electrical safety evidence. For sites in England or Wales, have the operator check combustion-plant and specified-generator requirements: applicable rules set emission controls, and emission limits are permit conditions. Before applying for a specified-generator permit, the operator must demonstrate it can comply with its conditions.

Worked duty example

Illustrative example, not a quote: A skid-mounted spark-ignition biogas generating set (illustrative order) under 8502 20 40 90, invoiced at £90,000 free on board, with £5,000 of freight and insurance to the UK. The customs value is £95,000. Duty at 0% is £0. Import VAT at 20% is charged on the customs value plus duty, £95,000, so it is £19,000. With no duty, the only import tax is the VAT, which a VAT-registered importer can usually reclaim. The import duty and VAT guide explains each step.

Inspection checklist

Fuel system: compare the gas train, filters and treatment equipment with the agreed scope; have a competent technician test joints for leakage and verify gas shut-off operation.

Output: witness a sustained load test and record fuel conditions, electrical output, voltage, frequency, coolant temperatures and any heat recovered.

Documents: match engine, alternator and controller identifiers to the declaration, manuals and test records; check electrical protection and earthing during inspection.

Arrival: check mounts, pipe connections, exhaust components and heat exchangers for movement or damage; confirm loose accessories and service parts against the packing list before commissioning.

What goes wrong

A natural-gas test leaves the buyer without evidence of performance on the site's biogas. Watch for output promises without fuel conditions, treatment equipment omitted from the quotation, and warranties that exclude the fuel actually available. Moisture and contaminants can undermine operation; have the engine supplier accept the gas specification in writing.

Heat-recovery figures can be unusable when quoted without water temperatures and flow. Cooling, exhaust or control interfaces may also be left for the buyer to resolve. Agree the installation interfaces and acceptance test before shipment, and retain a record of the factory configuration for comparison on arrival.

Cambridge China Bridge sources these products for UK businesses, checking the factory and the documents before shipment. See factory verification. For components and parts, see sourcing for manufacturers.