A cascade of power failures across Cuba has plunged millions into darkness, with residents of high-rise buildings in Havana facing a particularly precarious situation. The collapse of the island's ageing power grid, attributed to fuel shortages and infrastructure decay, stands in stark contrast to the United Kingdom's comparatively robust energy system. But as a climate scientist, I must note that this is not merely a tale of two islands; it is a glimpse into a future that awaits us all if we fail to decarbonise and modernise.
The Cuban blackout, now in its third day, saw generation capacity fall below 200 megawatts, a fraction of the 600 megawatts needed for peak demand. In high-rise apartments, lifts ceased to function, water pumps fell silent, and residents were trapped in stifling heat. For those on upper floors, the daily trudge up 20 flights of stairs became a survival exercise. Hospitals switched to backup generators, but fuel for these was also running low.
This is a story of infrastructure strangled by dependence on fossil fuels. Cuba's power plants, many built during the Soviet era, rely on heavy fuel oil and diesel. When global prices rise or supply chains falter, the grid falters. The UK, by contrast, has invested in a diversified mix of gas, nuclear, wind, and solar. National Grid's system operator can call upon interconnectors to France, Belgium, and Norway, providing a buffer against localised failures. Yet even this advantage is not absolute.
The underlying issue is the same: our energy systems are not built for the climate we now inhabit. Extreme heat waves, droughts, and storms are becoming the norm. In July 2022, the UK saw temperatures exceed 40°C for the first time, causing rail lines to buckle and power cables to sag. Cooling demand surged, pushing the grid to its limits. Cuba's blackout was triggered by Hurricane Ian in 2022, but the chronic instability is a result of chronic underinvestment and exposure to global fuel markets.
There is a bitter irony here. Cuba has some of the highest solar irradiation in the Caribbean, yet solar panels account for less than 1% of its electricity generation. The UK, despite its famously grey skies, has seen a boom in wind power, which now provides over a quarter of its electricity. But both nations face the same structural challenge: the need to transition from centralised, fossil-fuel-dependent grids to distributed, renewable networks. The difference is that the UK has the capital and technical capacity to do so. Cuba does not.
What does this mean for the average Brit? It means that our resilience is not guaranteed. The energy transition is not just about decarbonisation; it is about survival. A future of more frequent extremes will test every grid. The UK's National Grid has published scenarios showing that without significant demand-side flexibility and storage, blackouts could occur during calm, cold winter evenings when wind generation is low. The solution is not to build more gas plants but to deploy batteries, demand response, and interconnection at scale.
Cuba's blackouts are a warning. They show what happens when a country's energy infrastructure is both outdated and externalised. The UK must learn from this: resilience is not about having more backup, but about building a system that can operate independently of fossil fuels. That means insulating homes, installing smart meters, and rewarding citizens for shifting consumption to times of abundance.
As I write this, the blackout in Cuba continues. Families in high-rise buildings on the Malecon are lighting candles, sharing food, and climbing stairs. They are showing resilience of a different kind. But they should not have to. The planet is warming, and our grids must adapt. The question is whether the UK will heed this lesson or wait for its own moment of darkness.
