Integrated Drone Inspections for Energy from Waste: Thermal ACC Survey and Internal Boiler Gas Pass Inspection

How pre- and post-outage drone inspections enhance maintenance planning, safety, and operational efficiency in EfW and biomass plants

At DJM Aerial Solutions, we understand the critical nature of planned maintenance outages within Energy from Waste (EfW) and biomass facilities. These windows offer limited time to inspect, assess, and rectify key asset issues — making efficient data capture before and after shutdowns absolutely essential.

We recently completed a dual-phase drone inspection for an EfW operator, combining a pre-outage thermal survey of an operational Air Cooled Condenser (ACC) using our M300 drone with XT2 thermal payload, followed by a post-outage internal boiler inspection using the Elios 3. Together, these operations provided a complete integrity snapshot of two of the facility’s most critical systems.

Pre-Outage Thermal Survey of Operational Air Cooled Condenser (ACC)

Using our Matrice 300 RTK drone equipped with a FLIR XT2 thermal imaging sensor, we conducted a high-resolution thermographic inspection of the facility’s ACC while fully online. The purpose of this pre-outage survey was to identify:

• Air leakage across finned tube bundles

• Hot and cold anomalies indicating reduced heat rejection performance

• Fan malfunctions or uneven temperature distribution

• Structural deterioration or potential failure points

• Bypassed or blocked cells

Why This Matters in Energy from Waste and Biomass Plants

ACC systems in EfW and biomass settings must perform efficiently to maintain process stability and compliance. Even minor leaks or thermal inefficiencies can contribute to:

• Reduced turbine back pressure performance

• Increased parasitic energy consumption

• Reduced thermal efficiency and plant output

• Higher operating costs and emissions

• Accelerated wear on mechanical systems

By conducting a drone-based aerial thermography survey ahead of the outage, on-site engineers were able to prioritise repair efforts and procure parts in advance, improving the planning accuracy and maintenance efficiency of the scheduled works.

Post-Outage Elios 3 Boiler Inspection – Gas Pass 1

Following the outage and prior to boiler deslagging operations, DJM Aerial Solutions deployed the Elios 3 internal inspection drone to survey the first gas pass of the facility’s large-scale combustion boiler.

This confined space inspection aimed to detect:

• Refractory lining failure or spalling

• Exposed or distorted boiler tubes

• Corrosion or thinning in high-temperature zones

• Blockages or ash accumulation

• Misalignments or structural distortion of steelwork

Elios 3: A Safer Alternative for Confined Space Inspection

With its 360° LED lighting, stabilised 4K camera, and onboard LiDAR sensor, the Elios 3 captured every inch of the gas pass in rich visual and spatial detail — without requiring any manned entry or scaffold erection.

This gave site engineers the ability to:

• Visualise internal damage prior to deslagging

• Target problematic areas for more intensive repair

• Verify condition post-refractory inspection and prior to recommissioning

• Minimise time spent in confined space for follow-up works

Key Benefits for EfW and Biomass Operators

Maintenance Planning with Data

Combining pre-outage aerial thermography with post-outage internal drone surveys creates a closed-loop dataset that informs decisions across the full shutdown lifecycle.

Zero Downtime for Pre-Outage ACC Survey

All thermal imaging was captured during normal operation, with no interruption to generation or cooling capacity.

Risk-Free Internal Boiler Inspection

The Elios 3 eliminates the need for confined space entry and scaffolding, protecting personnel and accelerating reporting.

High-Quality Reporting

Both inspections delivered high-resolution imagery, defect tagging, and 3D spatial mapping to support engineering interpretation and regulatory documentation.

Cost-Efficient

Avoiding unnecessary shutdowns or over-preparation, clients save significantly on access, labour, and remedial scope planning.

Why It Works: Seamless Integration with Engineering Teams

At DJM Aerial Solutions, we don’t just fly drones — we integrate our deliverables into your asset integrity, maintenance, and compliance workflows. Whether you operate under EEMUA guidelines, API standards, or internal engineering codes, our outputs are built for compatibility and actionability.

Typical Applications in Energy from Waste and Biomass Sites

• Air Cooled Condenser leak detection (ACC)

• Thermal performance surveys of heat exchangers and ducting

• Flue stack inspection (internal and external)

• Gas pass inspections of boilers (Pass 1, 2, 3)

• Post-refractory inspection

• Cyclone separator and hopper integrity survey

• Bin and silo internal condition assessment