Havana is dark. Not the romantic darkness of a city without light pollution, but the oppressive black of a failed grid. On 18 October, a cascading failure at the Antonio Guiteras thermoelectric plant plunged millions into blackout, the fourth such event in a month. High-rise buildings in the capital became concrete tombs of silence, generators sputtering to a halt as fuel reserves ran dry. For Cuba, it is a crisis of infrastructure compounded by blockade. For the rest of the world, it is a case study in what happens when a national grid falls behind the demand curve of a warming planet.
Cuba’s grid, comprising eight ageing thermoelectric plants, operates on a knife-edge. Most units are over 30 years old, running on domestic heavy fuel oil cut with imported crude. Maintenance is sporadic, parts are scarce, and when a single unit trips, the load shifts onto others. The result is a domino collapse: frequency drops, voltage sags, and the entire system separates into islands that cannot synchronise. The blackouts are not accidental. They are structural.
Enter the UK’s Energy Systems Catapult, which has offered a model for reform. Their proposal is not a Band-Aid but a blueprint for a managed transition. It involves three layers: first, a distributed control architecture that allows portions of the grid to operate independently using local generation; second, a market mechanism for demand-side response that rewards consumers for reducing load at peak times; third, a long term plan to phase out thermal plants in favour of solar plus battery storage, which can be deployed faster and at lower capital cost per megawatt than new thermoelectric units.
Cuba has natural advantages for this transition: high solar irradiance, a skilled workforce, and a population accustomed to resourcefulness. Yet the political context cannot be ignored. The US embargo restricts access to advanced grid components and financing. The UK model would require hardware upgrades at the substation level, smart meters, and communication infrastructure all of which are subject to trade restrictions. Still, the fundamental physics remains. Any grid, anywhere, must balance generation and load in real time. Storage is the buffer that allows renewables to provide base load without fossil fuel backup.
Consider the analogy of a thermal flywheel. In a conventional plant, the spinning turbine provides inertia that smooths out fluctuations in demand. As plants are retired, that inertia disappears. Without it, frequency changes can cascade faster than control systems can react. Battery storage, when configured with grid forming inverters, can mimic that inertia electronically. In the UK, the National Grid ESO has already demonstrated that a 50 megawatt battery can provide synthetic inertia faster than a steam turbine. Cuba needs this now.
The blackouts are not an anomaly. They are a symptom of a global pattern: ageing infrastructure, increasing heatwaves, and fuel supply fragility. Every tropical nation with a centralised grid should look at Havana’s darkened high rises and see a future they must avoid. The UK offer is a model but models require implementation. Without political will and external support, the lights will stay off. The science is clear. The engineering is ready. The only missing variable is decision.
As I write this, the temperature in Havana is 28 degrees Celsius. The humidity is 80 per cent. Without air conditioning, those high-rise buildings become heat traps. This is not a story about energy. It is a story about survival. And the clock is ticking.
