By the UK Wood Gasifier Hub – Off-Grid Power & Biomass Energy Guides Team · Updated May 2026 · Independent, reader-supported

How to Connect a Wood Gasifier to a Generator UK: Step-by-Step Setup Guide

Connecting a wood gasifier to a generator is an increasingly popular way for UK homeowners to generate electricity from waste wood and garden material. Unlike burning wood in a stove, gasification converts the wood into combustible gas, which then powers a conventional petrol or diesel generator. The process is straightforward in principle but requires careful attention to the gas preparation stage—this is where most people get it wrong.

Understanding the Basics

A wood gasifier produces syngas (a mixture of carbon monoxide, hydrogen, and methane) rather than burning the wood directly. This syngas needs cleaning and cooling before it reaches your generator's engine. The gas carries tar, moisture, and fine particles that will clog or damage an unprepared engine. This is why the "gas train"—the series of components between the gasifier and generator—is critical to reliable operation.

Most setups use a petrol generator rather than diesel, because petrol engines are more forgiving of the variations in gas composition and require fewer modifications. A typical 5–8 kW generator will run on syngas once properly converted, giving you several kilowatts of usable power from a single gasifier burn.

The Gas Train: Your Foundation

The gas train performs three essential jobs: it removes large particles and water, cools the gas to a safe temperature, and regulates the fuel mixture reaching the engine.

Component layout (in order):

1. Cyclone or particle trap – Captures ash and char particles immediately after the gasifier outlet.
2. Water trap – Allows condensate to settle and drain; you'll need a manual drain valve here.
3. Cooler – Usually a simple radiator or coiled pipe with a fan; cools the gas from 200+ °C to under 60 °C.
4. Final filter – A high-capacity air filter (often repurposed from a car engine) removes remaining fine particles and tar mist.
5. Carburettor or fuel mixer – Blends the syngas with air in the correct ratio for combustion.
6. Mixing valve – A needle valve that lets you fine-tune the gas-to-air ratio during operation.
7. Non-return valve – Prevents backflow if the engine misfires.

Spacing matters. Keep hot sections away from the cooler and filter to prevent moisture re-condensation. Use stainless steel or mild steel hose rated for high temperature—ordinary rubber fuel line will melt or perish in weeks.

Step-by-Step Setup

1. Mount the gasifier and gas train outdoors. Wood gasifiers produce fumes and smell strongly. Position the unit at least 2 metres from windows and doors. The generator will sit 5–10 metres away, depending on your hose runs.

2. Build or source your gas train. Many UK gasifier enthusiasts build custom trains from agricultural or industrial fittings. A 4-inch (100 mm) steel pipe works well for the cyclone. The cooler can be a small car radiator with a 12 V brushless fan (powered from the generator's output). For the filter, a large K&N or similar aftermarket car filter will handle 5–8 kW output. Budget £150–400 depending on whether you source second-hand parts.

3. Connect the gasifier outlet to the gas train. Use high-temperature braided hose or rigid stainless pipe. Ensure the connection slopes slightly back to the gasifier—any pooling of condensate in the line will block flow.

4. Install the carburettor conversion. This is where many fail. You cannot simply pipe gas into a standard petrol carburettor. You need either a dedicated carburettor (expensive, hard to find in the UK) or a simpler approach: run the gas through a venturi mixer upstream of the standard carburettor. The venturi creates suction that pulls the gas in, mixing it with air automatically. This method works well for generators and requires no modifications to the original carburettor—just a bypass of the fuel tank.

5. Connect the mixer to the engine. Remove the standard fuel line from the tank and cap it off. Route the syngas line to the venturi, then to the standard carburettor inlet. A small length of rubber hose here (away from heat) absorbs vibration.

6. Set up drain points. Install a manual drain tap at the water trap. Every time you run the gasifier, condensate builds up. Open this drain at the end of each session—ignoring this step will lead to water in the engine and rust damage.

7. Add a mixing valve. A simple needle valve between the filter and carburettor inlet lets you adjust the gas-to-air ratio while the engine is running. This is essential for stable idling and load response. Install it where you can reach it from the generator controls.

First Run and Tuning

Start the generator on petrol by disabling the gas line (crimp it or fit a ball valve). Once running smoothly on fuel, slowly open the gas supply valve. The engine should rev down as syngas takes over. Use the needle mixing valve to find the sweet spot—the engine should run smoothly without excessive popping or stalling.

Expect hunting (rev fluctuation) until you dial in the ratio. This is normal. On load (lights, tools running), the engine should settle into steady operation. Without load, it may still hunt slightly, which is acceptable.

Common Issues

Tar blockage: If the engine bogs down after 20 minutes, you likely have tar in the cooler. Install a cooler with larger capacity or run the fan continuously.

Water in the engine: Drain the water trap religiously. If you forget and water reaches the engine, you'll need to drain the sump and replace the oil.

Poor idling: Adjust the mixing valve slowly. Small changes make big differences. If the engine won't settle, your gas production may be inconsistent—check that wood moisture is below 20% and that you're not running the gasifier too lean.

Governor hunting: Some generators have governors that fight syngas variability. A manual choke or hand throttle (fitted in place of the governor) works better, but this means you'll control speed manually.

Safety Notes

Wood gasifiers produce carbon monoxide. Run them outdoors always, never in sheds or buildings. Syngas is flammable and will escape if hoses split; inspect connections regularly. Keep a fire extinguisher nearby—woodsmoke and overheated gasifiers are fire risks.

Conclusion

Connecting a wood gasifier to a generator is achievable for a competent DIYer. The skill lies in building a reliable gas train and understanding the fine tuning required. Your investment is modest—£300–600 in components—but the reward is consistent, renewable power from material you'd otherwise burn or discard. Once running smoothly, it's a satisfying, low-cost way to generate electricity.