Why is energy resilience so important for Guernsey?
Guernsey relies heavily on the undersea cable link to import most of its power from France. When this link fails, the island must fall back on diesel generation, which is costly, carbon-intensive and limited in capacity. Recent history shows how vulnerable this dependency can be.
Guernsey has already experienced major cable-related failures:
1. The 2018 GJ1 Cable Failure
In November 2018, Guernsey’s main subsea cable to France (GJ1) suffered a catastrophic failure. The island had to run almost entirely on local diesel generators for months while replacement works were arranged. This dramatically increased generation costs and exposed how fragile our energy supply can become when imports stop.
2. The 2019 Island-Wide Power Cut
In September 2019, during work on another cable, an unexpected fault triggered an island-wide blackout at rush hour. Homes, businesses and transport were disrupted, and supply was only restored once local generators stabilised the grid.
These two events are clear warnings: Guernsey is highly dependent on a small, external connection. If it fails, the island faces immediate operational and financial consequences.
Why on-island renewables matter
1. They reduce reliance on the cable
Solar panels and battery systems generate and store energy here on island, lowering the amount of electricity we need to import.
2. They create distributed energy resilience
A home with solar and a battery bolster the grid. If a home has a NanoGrid, which a battery with back up, it turns the home into an off-grid power plant capable of operating independently for periods of time. When thousands of homes do this, the whole island becomes more stable and less vulnerable to external failures.
3. They protect against outages and price shocks
If the cable is disrupted, homes with batteries stay powered, and the island needs less diesel backup. More local generation also reduces the financial shock of switching to expensive emergency generation.
4. They strengthen the local economy
On-island renewables keep energy spending local, reduce exposure to imported fuel costs and build long-term stability.
The bottom line
Guernsey has already seen what happens when the cable fails — once in 2018 and again in 2019. Building on-island renewable energy and household NanoGrids is the modern solution to this vulnerability.
Every solar panel and every battery installed makes the island cleaner, stronger and more resilient.
