Detect grid cable failures with Greenlight™ by Synaptec
The hidden cost of grid downtime
A single fault in an underground high-voltage cable can cause widespread blackouts, create public safety risks, and cost operators hundreds of thousands of pounds in emergency repairs, penalties, and lost supply.
Nearly 70% of these faults originate in joints and terminations – the most vulnerable and least monitored parts of the network.
Introducing Greenlight™ – a smarter way of monitoring grid cables
Purpose-built for power transmission and distribution systems, Greenlight™ uses Synaptec’s patented Distributed Electrical Sensing (DES) technology to deliver real-time, passive insight into cable joints and terminations.
It replaces unreliable manual inspections and reactive maintenance with continuous, automated monitoring – before failures happen.

Key benefits for grid operators
Predictive condition monitoring
Continuously monitor in real-time for early signs of failure, such as abnormal current flow, thermal stress, or phase imbalance.
Pinpoint accuracy
Monitor with accuracy – so you can intervene quickly and precisely.
No power or comms needed
DES sensors operate passively via standard optical fibre. No power, no recalibration, no field visits.
Enhanced safety & uptime
Reduce the need for field inspections and emergency call-outs. Keep networks online and teams safe.
Rapid deployment
Sensors are easily embedded in new infrastructure or retrofitted to existing assets.
How it works
1. DES sensors
2. Synchronised data
3. Real-time analysis
4. Automated alerts & dashboards
Outperforms traditional monitoring
Legacy methods | Greenlight™ |
Manual inspections | 24/7 passive, automated monitoring |
Infrared scanning | Real-time insight of cable condition |
DTS/DAS systems | True visibility inside joints and terminations |
Field diagnostics | Pinpoint accuracy without sending teams out |
Power-dependent sensors | Fully passive, zero-maintenance design |
Greenlight is trusted by TSOs and DSOs across the world.
As energy infrastructure ages and loads increase, Greenlight offers a future-proof way to maintain network resilience and reliability – without increasing operational complexity.
Large-scale rollouts are scheduled for 2025.

FAQs
Q: Can it be used in urban networks or substations?
A: Yes. It’s ideal for underground HV infrastructure and compact substations with limited access.
Q: Does it work on AC and HVDC networks?
A: Yes. Greenlight supports both AC and DC configurations.
Q: How long do the sensors last?
A: They’re fully passive with no moving parts—so they require no replacement, recalibration, or servicing.
Q: How quickly can it be installed?
A: Very quickly. Sensors are deployed on existing optical fibre, using industry-standard CTs or VTs.
Find out more
Download our flyer below to see how Greenlight is transforming grid monitoring strategies across Europe.