A solar-powered wellhead flare burns landfill gas at the wellhead using the gas’s own pressure, with a solar-charged battery supplying only the ignition. There is no gas booster and no power line, so it suits remote sections of a landfill. This post explains how a 100–150 m³/h design works, how it was reduced in scope to cut cost, and when it is worth considering.
The challenge: gas to control, no power to run a booster
Conventional flares rely on a gas booster, which needs a three-phase electrical supply. Some landfills, especially older or remote ones, have no mains power near the wells. Gas still reaches the surface under its natural pressure and needs to be burned, not vented.
A distributor for a landfill operator in Portugal asked about a flare that could work without power lines. After discussion with the supplier’s engineers, a design was proposed and then revised to a lower-cost version.
The approach: the SP Range wellhead ground flare
How it works
The flare sits on a wellhead or a small group of wells and burns gas that emerges naturally. Gas is collected through a manifold into a condensate pot, passes a flame arrester and a manual trim valve, and goes to the burner. A solar cell charges a battery on the unit. That battery supplies electric ignition at start-up, so no external supply is needed.
Two versions
| First quotation | Revised, lower-cost quotation | |
|---|---|---|
| Maximum flow | 150 m³/h | 100 m³/h |
| Typical wellhead flow it suits | 10–50 m³/h | 10–20 m³/h |
| Inlet | Four-way manifold collecting from several wells | Single inlet port |
The second version reduced the extent of the supply while keeping the method unchanged. It is the sensible choice where a single well, or a few low-yield wells, feed the flare.
Common features
- Combustion: at least 1,000°C when methane is above 30%, cooler as methane falls. Minimum residence time 0.6 seconds and a 10:1 thermal turndown.
- Control: automatic flame temperature control.
- Insulation: 100 mm of high-temperature ceramic blanket held with twist-lock caps.
- Instruments: a feed pressure gauge and insertion points for an anemometer or pitot tube on each inlet.
- Build: a skid-mounted unit, galvanised pipework, an IP55 control panel and four lifting eyes.
Why it works, and where it does not
A booster-less flare relies on gas pressure at the wellhead. If the gas is weak or the well is poorly sealed, the flare may not get enough flow to hold temperature. That is why the design is quoted for specific flow ranges and a methane threshold of 30%.
There is a second limit. Without a booster, the flare cannot apply suction to the waste. It burns what comes out. That means it does not provide active gas extraction or migration control in the way a conventional extraction system does. For guidance on active gas control, see the Environment Agency’s LFTGN03.
What to consider for your own project
- Measure the wellhead flow first. Typical flows in the quotations ranged from 10 to 50 m³/h. If yours is much lower, the flare may not sustain a flame.
- Check methane concentration. The design assumed above 30%.
- Decide whether you need suction. If you do, you need a booster and a power supply.
- Consider multiple units. A volume discount was offered for orders of 5, 10 or 20 units, which suits a site with many small wells.
- Estimate flows by modelling. The supplier offered help with its own gas production modelling programme.
- Plan for maintenance. A solar cell and battery need checking in dust or low-light conditions.
FAQ
Can a landfill gas flare run without mains power?
Yes, if it uses natural gas pressure and only needs power for ignition, which a solar-charged battery can provide.
How much gas does a wellhead flare handle?
The designs described handle up to 100 or 150 m³/h, with typical wellhead flows of 10 to 50 m³/h.
Is a solar flare as clean as a conventional one?
Designed to hold 1,000°C above 30% methane, with a residence time of 0.6 seconds. Below that methane level it burns cooler.
Can it extract gas?
No. It has no booster, so it burns only the gas that reaches it under natural pressure.
Remote wells that need gas control?
Tell us about your wellheads and we will advise whether a solar-powered flare or a powered system is the better fit.