How Drones Can Benefit Biogas Plants: Digester and Pipe Checks

How can drones benefit biogas plants?

Drones for biogas plants do one job well. They let a trained crew see the inside of a digester, a membrane cover or a run of gas piping without climbing, building scaffold or sending a person into a confined space. For an operator, that can mean fewer days of planned work to inspect a tank, and a smaller chance that a small crack or seam problem turns into an unplanned shutdown.

The main problem drones solve is costly unplanned downtime from tanks and piping that go unchecked. Digesters, gas holders and piping runs are tall or hard to reach, so they often get a close look only when a crew can be spared. A drone can survey those surfaces on a regular schedule, which keeps the gap between inspections short.

Use drones alongside your crew and maintenance plan, not in place of them. The best results come when the footage shows where people are needed, and when the crew does the repair. The sections below cover the problem today, where the benefits are documented, how the work runs day to day, and how to start.

What does inspection look like at a biogas plant today?

Most biogas plants inspect tall assets with methods that take time. A vendor describes membrane inspection on biogas covers as often relying on scheduled rope access, periodic drone flyovers and manual photo documentation. The same vendor notes that rope access on high covers depends on favorable weather, specialized crews and extended downtime.

Tanks add a confined space problem on top of height. Before anyone enters a digester, it has to be emptied, cleared and made safe, and that work takes the tank out of service. Scaffold erected inside the vessel adds more days before the inspection even starts.

Plants of this kind are numerous enough that the same problem repeats across many sites. According to the EPA AgSTAR program, there were 400 operational manure-based anaerobic digestion projects in the US as of June 2024. The same agency notes that its database is not exhaustive, so the count is a floor, not a full census.

The count has been climbing. BioCycle reporting on AgSTAR data put the total at 317 operating manure-based anaerobic digestion systems as of September 30, 2021. An early 2021 EPA snapshot listed 263 projects on livestock farms, and an EPA archive page recorded 176 systems at the end of 2011. The counts are not fully comparable, so read them as a trend in the field rather than a single series.

Where do the main benefits show up?

The clearest benefit is less time in lift and scaffold work. In a digester refurbishment at a Welsh wastewater works, reported by trade press, an engineer flew a drone inside a digester after it had been emptied and made safe. The survey guided internal scaffolding, repairs and a protective coating on the headspace, so the drone shaped where crews spent their time rather than replacing them.

A second benefit is a safer inspection. A vendor case study describes a zero-entry digester inspection in which a confined-space drone was launched through a small ground-level access point, so no one entered the tank. The vendor reports the inspection finished in hours rather than days and let the tank return to service faster. That is a single vendor-reported case, and the scope and tank details were not published.

A third benefit is a visual record. Drone footage gives maintenance and management a dated set of images for each cover, tank wall and pipe run, which makes it easier to compare conditions from one visit to the next.

How does a drone work at a plant day to day?

Day-to-day work starts with the checks any entry requires. Confirm the tank is cleared and safe, agree the flight window with operations, and check the access point and lighting. The flight itself is short, but the review afterward takes the most skill, because someone must tag each defect in the footage.

Interior flights need a launch point and a plan. The vendor case launched through a small ground-level opening, which kept the pilot and crew outside the vessel. Surveys of covers and piping run on a set route, with each section photographed in the same order so the next visit lines up with the last.

Expect a shift rhythm rather than a single visit. A typical day includes a pre-flight check, the interior or cover flight, a same-shift review and a handoff of findings to maintenance. That loop keeps the decision about scaffolding or repair with your own team.

Which areas of the plant does the drone cover?

Drones suit the tall or hard to reach areas of a biogas plant. They are most useful where a person would otherwise need a lift, a scaffold, rope access or a confined space entry.

Six areas usually matter most at a plant, and each one calls for a different kind of check. The area guide below walks through each one and what the flight looks for.

Does the drone replace my crew?

No. A drone works alongside a plant team, and the best setups keep a smaller team of trained people around it. You still need an operator who can read the footage, a maintenance lead who can decide on repairs, and a crew for the work the footage calls for. The aim is fewer blind lifts and fewer unplanned shutdowns, not fewer people on site.

The staffing picture matters here too. According to the BLS Occupational Outlook Handbook, water and wastewater treatment plant and system operators held about 132,400 jobs in 2024, and local government excluding education and hospitals is the largest employer at 74%. Those operators are the closest government-tracked role to a biogas operator, so the figures give a sense of the workforce, though they describe a related job rather than biogas staff.

Training is part of the setup. Operators need to learn the flight and review workflow, and a maintenance lead needs to know what a flagged defect looks like before a shutdown begins.

What drives the savings?

Savings come from hours and days. The biggest driver is the time a tank stays out of service while people build access, empty and clear the vessel and wait for crews. Any inspection that shortens the window before a repair or return to service reduces downtime.

Labor savings come from fewer hours on lifts, scaffold and rope work, and from fewer crew mobilizations. The vendor case gives the clearest example, with an inspection that finished in hours rather than days. No independent hour figure per digester inspection was found, so treat that case as a starting point for your own measurement.

Measure before and after. Track the hours spent on each inspection type, the days each tank stays out of service, and the number of findings that led to planned work rather than emergency repairs. Those three numbers show whether drones are worth the effort at your site.

What can a drone not do?

A drone cannot do the repair. It can show a crack, a coating breakdown or a loose cover panel, but a crew still has to fix it. Where the footage shows damage that needs scaffold, the drone has narrowed the scope rather than removed the scaffold, as the UK project shows.

Weather and light limit flights, and a camera cannot see through liquid or sludge. Contact measurements, such as wall thickness, need a different tool. Fixed or handheld intrinsically safe cameras are another option for hazardous spaces where a drone is not suitable.

Every flight also depends on your site rules. Confirm the plan with your safety lead and check local airspace requirements before flying near tanks, covers or flare areas.

How do we get started?

If you are weighing drones for biogas plants at your site, start with a free site assessment. Our team walks the plant, notes the tanks, covers, piping and flare areas that matter most, and recommends the right aerial unit for the site. Nothing is leased until that assessment is complete.

We lease the unit through financing programs, then deploy and integrate it on your site, train your staff and service it nationwide. The payment comes in the quote, and the quote follows the site assessment.

A common first step is one unit on one set of assets, with a pilot period to measure hours and downtime. If the numbers hold, you can extend the work to other tanks and runs. We support the work through go-live and after, so your team keeps a clear plan for every inspection.