Russia Deploys Low-Cost, Fiber-Optic Drones to Bypass Ukraine's Power Grid Defenses

Russia is deploying a new, low-cost drone tactic to bypass extensive Ukrainian defenses and damage high-voltage electricity substations in the frontline Sumy region. The strategy involves small, nimble First Person View (FPV) drones guided by fiber-optic cables, making them immune to conventional radio-signal jamming, according to analysis by the Centre for Information Resilience (CIR), a London-based open-source investigation group.

A New Method of Attack

Ukrainian authorities have fortified critical energy infrastructure with concrete enclosures and anti-drone nets to protect against missile and larger drone strikes. However, Russian forces are now using a two-step FPV drone approach to circumvent these measures. An investigator at CIR, Joshua Scriven, explained that an initial drone is used to create a hole in the protective netting, allowing a second drone to fly through the gap and target vital equipment.

These fiber-optic-tethered drones navigate around the large protective structures to strike the central autotransformer. Because they are physically connected to an operator via a thin cable, they are not susceptible to the electronic warfare systems prevalent in frontline areas.

Economic and Strategic Implications

The financial disparity of this new tactic is stark. An FPV drone can cost as little as $2,000, while the autotransformer it targets in a 330-kilovolt (kV) substation is valued at approximately $3.5 million, according to Oleksandr Kharchenko, head of the Energy Research Centre in Kyiv. The destruction of this single component can disable the entire transformer unit.

CIR has verified at least eight such attacks since May:

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• Four strikes on large, well-defended 330 kV substations.
• At least four additional strikes on smaller 110 kV substations.

These attacks have occurred between 16 and 26 kilometers (10-16 miles) from the frontline, demonstrating the increasing operational range of these small, tethered drones.

Broader Campaign Against Energy Infrastructure

These strikes appear to be part of a wider Russian strategy to degrade Ukraine's energy grid and isolate regions from national power supply. By targeting local substations after compromising links to the national grid, the attacks aim to cause blackouts. Ukrainian Defence Minister Mykhailo Fedorov noted in a statement that the security situation in the Sumy region had deteriorated in June, stating Russia's goal is to "terrorise people."

Russia has consistently targeted Ukrainian energy facilities throughout the conflict. The International Criminal Court has previously issued arrest warrants for senior Russian commanders in connection with strikes on Ukraine's power grid. Russia denies targeting civilians, maintaining that its strikes serve a military purpose.