The island nation of Cuba, long accustomed to the ebb and flow of geopolitical tides, now faces a more elemental crisis. This week, rolling blackouts swept through Havana, plunging high-rise apartments into darkness and shutting down critical infrastructure. The cause is a familiar one: an ageing, fossil-fuel-dependent grid crumbling under the strain of extreme weather and deferred maintenance. For the UK, this Caribbean island’s plight serves as a distant early warning. Our own energy system, though more robust, shares structural vulnerabilities that demand immediate attention.
Consider the physics. Cuba’s grid relies on oil-fired plants often situated on vulnerable coastlines. Hurricanes and rising sea levels have damaged transmission lines, while fuel supply disruptions from geopolitical tensions have exacerbated shortages. The result is a cascade: power plant failures lead to load shedding, which triggers further instability. This is not just a technical failure but a thermodynamic one. When the sun sets and demand peaks, there is no stored energy to bridge the gap. Batteries would help, but large-scale storage remains absent.
The UK’s energy transition faces analogous challenges. We have made strides in renewables: wind now supplies over half of our electricity on some days. But wind is intermittent. A single calm anticyclone across the North Sea can drop output by 80 per cent. Without sufficient storage or dispatchable backup, we risk the same grid fragility. Cuba’s blackouts are a preview. Their grid frequency dropped to 49.5 Hertz before collapse. Our National Grid operates at 50 Hertz plus or minus 0.5. Exceed that tolerance and protective relays disconnect power stations, triggering a chain reaction. It is a matter of timing, not inevitability.
To avoid Cuba’s fate, Britain must invest in three pillars. First, long-duration energy storage: pumped hydro, compressed air, and flow batteries. The UK has pumped hydro at Dinorwig but needs more. Second, dispatchable low-carbon power: new nuclear and hydrogen-ready gas turbines that can ramp up when renewables wane. Third, smart grid infrastructure: demand-side response that shifts consumption to off-peak hours, and networked microgrids that isolate failures. The cost is substantial, estimated at £100 billion by 2035. But the cost of inaction is higher. Cuba’s GDP contraction from blackouts is projected at 2 per cent annually. For the UK, a comparable loss would be £40 billion per year.
There is also a personal dimension. I spent my early career studying stellar atmospheres, where energy transport is elegantly efficient. Here on Earth, our systems are brutish by comparison. We waste a third of all energy generated through heat dissipation and transmission losses. Efficiency is the cheapest fuel. Retrofitting buildings with insulation and heat pumps could halve demand growth. But this requires policy consistency: the government’s heat pump subsidy programme has been upended four times in five years.
Cuba’s blackouts are not an isolated tragedy. They are a symptom of a global energy transition underway. The UK must decide whether to lead or follow. Our North Sea wind resources are world-class, but they are worthless without a grid that can handle their variability. The technology exists. The capital is available. What lacks is the political will to endure short-term costs for long-term resilience. As the lights flicker in Havana, British policymakers should take note. Our own high-rises may not be far behind.
