Ground-mounted solar parks are large, unstaffed and often remote, which attracts organised cable-theft gangs. A drone-in-a-box system keeps a drone in a weatherproof base station on site, flies autonomous patrols and lets an operator verify alarms with live video. Nestua is building one: the software platform is functional in development builds, and the drone and base station hardware are still being built.
- Cable is the main target: over 750 km was stolen from UK solar farms in January–August 2024 (DeterTech).
- A drone can patrol the fence and cable routes on a schedule and fly to an alarm location.
- An on-site edge node keeps patrols, video and detection running without internet.
- Flights near grid equipment, roads and neighbours need geofences, a risk assessment and a GDPR review.
Why are solar parks in Europe targeted by thieves?
The value at a PV park is in its copper and aluminium string and DC cable, then inverters and modules. Security intelligence firm DeterTech, which shares data with the UK National Police Chiefs' Council, reported more than 70 theft incidents at UK solar sites in the first eight months of 2024. More than 20% of them involved at least 20 km of cable. The same firm estimates around 5,000 "major" solar thefts a year across Europe, about 400 of them in Germany. These are industry estimates, not official statistics.
Police data is patchier but points the same way. In Brandenburg, recorded thefts at solar installations rose from 33 in 2021 to 54 in 2023, although police expected a fall in 2024. Police there say offenders prefer sites that nobody visits regularly but that are easy to reach by road, which describes most utility-scale parks. DeterTech also reports that sites are often hit again soon after the cable has been replaced.
Why do fixed cameras and guard patrols leave gaps at PV parks?
- Perimeter length. A large park can have kilometres of fence. Full camera coverage needs many poles, power and network runs, and module rows block the view.
- Time to verify. Fence sensors and video analytics raise alarms, but wind, animals and vegetation cause false ones. If a guard has to drive out for every alarm, response times grow and alarms get ignored.
- Night and remoteness. Thefts happen at night on rural sites. A mobile guard covering several sites spends only minutes at each.
How would a drone-in-a-box patrol work on a solar park?
On a Nestua site, one edge node controls one drone. Operators use a browser-based cockpit, which can also be installed as an app. It shows a live map with the drone's position, heading and flight trail, satellite imagery of the park, and the mission and geofence overlays.
- Scheduled patrols. In the mission editor you draw waypoint routes along the fence line, cable trenches, inverter stations and the substation compound, then upload, start or stop them from the browser. Every mission action is written to the audit log.
- Alarm verification. When a fence or camera alarm fires, an operator can send the drone to that spot with a go-to command. A command only counts as done once the drone sends back a MAVLink acknowledgement. Critical commands need typed confirmation. How the drone links to your existing alarm system is something to agree during the project.
- Geofences. Polygon or circle no-fly zones keep the drone off neighbouring farmland, public roads, overhead lines and the grid-connection compound. A breach either blocks the command or triggers return-to-launch.
- Edge AI. YOLO-based detection of the "person" and "vehicle" classes runs on the NPU of the on-site NXP i.MX 8M Plus edge computer. AI rules turn a detection into an action: notify, record, hover or return to launch. These actions still respect safety policy and geofences, and they are rate-limited. The system detects object classes; it does not identify individuals.
- Evidence. Low-latency WebRTC video plays in the browser, with HLS as a fallback. Footage is recorded locally to a ring buffer and you can export clips for the police. Uploading recordings off-site is disabled by default.
- Unattended operation. The IP65-rated base station is designed to swap batteries robotically and to stay outdoors all year. A weather-monitoring service and watchdog-supervised services feed the system health page.
Why does offline-first matter at a remote solar park?
Many PV parks sit at the end of a rural mobile cell. A patrol system that stops when the LTE link drops, or is jammed, fails exactly when it matters. Nestua's offline-first design runs the whole control plane on the edge node. That includes flight control, missions, geofences, video, detection and the audit log. The radio link between drone and ground station uses its own encrypted protocol with per-packet authenticated encryption and hard mutual pairing.
The optional cloud adds remote viewing, policy-controlled remote control and multi-site fleet management. Remote access is off by default, and enabling remote control requires admin re-authentication.
Larger electricity producers may also fall within the NIS2 Directive. Annex I lists electricity producers as a sector of high criticality, subject to size thresholds and national transposition. Keeping video and logs on site, with exportable audit records, is designed to help operators meet those obligations; it is not a certification.
What drone and privacy rules apply at solar parks?
- Category. Automated patrols beyond visual line of sight fall outside the EU "open" category, which requires VLOS and a maximum height of 120 m. They normally need a "specific" category operational authorisation based on a risk assessment, under Articles 5 and 11 of Regulation (EU) 2019/947. See EU drone regulations.
- Geographical zones. Member States can restrict flights around certain areas. In Germany, for example, § 21h(3) LuftVO covers the area over and within 100 m of central energy generation and distribution facilities, and generally requires the facility operator's consent. Check the zones for your site and its grid connection.
- Privacy. The EDPB says cameras protecting premises should generally film only those premises, not neighbouring land or public areas. It also says footage should usually be deleted within a few days, with more justification needed beyond 72 hours. Systematic monitoring of a publicly accessible area on a large scale triggers a DPIA under GDPR Article 35(3)(c).
This page is general information, not legal advice.
What should a solar park operator evaluate?
- Flight time, battery swap cycle and how much of your fence a single patrol can cover.
- Night imaging performance and whether a thermal payload is needed. Ask for demonstrations, not datasheet claims.
- Wind, rain and temperature limits for your climate, and how the system behaves when weather grounds the drone.
- Integration with your fence detection, CCTV analytics and monitoring centre.
- The geofence plan: neighbours, roads, overhead lines and the grid-connection compound.
- Your authorisation path with the national aviation authority, and who acts as UAS operator.
- Retention periods, DPIA, signage and who may view or export footage.
- Base station power, and behaviour during a site power outage.
Sources
- Electrical Review, "Solar farms report 'unprecedented' surge in cable thefts" (DeterTech data), 4 Dec 2024: electricalreview.co.uk
- photovoltaik, "Diebstahl: Bleibende Unsicherheit" (Brandenburg police figures), 12 Dec 2024: photovoltaik.eu
- Commission Implementing Regulation (EU) 2019/947, Arts. 4, 5, 11, 15: eur-lex.europa.eu
- German Air Traffic Regulation (LuftVO), § 21h: gesetze-im-internet.de
- Directive (EU) 2022/2555 (NIS2), Annex I: eur-lex.europa.eu
- EDPB Guidelines 3/2019 on processing of personal data through video devices, v2.0: edpb.europa.eu
- Regulation (EU) 2016/679 (GDPR), Art. 35: eur-lex.europa.eu