A cascade of failures in Cuba’s ageing thermoelectric plants has plunged much of the island into darkness for a third consecutive week, with residents in high-rise buildings in Havana facing uniquely severe consequences. The blackouts, which have lasted up to 16 hours daily, have trapped people in upper floors without running water or elevator access, forcing emergency rescues by volunteers. As the Cuban government blames US sanctions and fuel shortages, UK renewable energy experts argue that decentralised solar and battery storage could break the cycle of collapse.
Cuba’s electrical grid, largely built in the 1970s, relies on 12 heavy-oil-fired power stations that operate well below capacity. On a good day, the country generates less than 1,200 megawatts (MW) against a peak demand of 2,800 MW. The recent breakdown of the Antonio Guiteras plant, the nation’s largest, reduced generation by a further 240 MW. This forced rolling blackouts that affect 80% of the population, but the impact is compounded in Havana’s concrete towers where pumps for water distribution and sewerage require electricity.
“We are seeing a humanitarian crisis layered on top of an energy crisis,” says Dr. Elena Zamora, an energy systems researcher at King’s College London who has studied island microgrids. “When power goes for 16 hours, people on the 15th floor cannot simply walk down 15 flights of stairs with water jugs. The elderly and disabled are effectively trapped in their apartments.”
The Cuban state utility, Union Electrica, has prioritised power to hospitals and pumping stations, but the system is too brittle. Each failed restart of a thermal plant requires hours of complex resynchronisation, often causing new failures. This cascading instability is a classic symptom of a stressed centralised grid.
UK experts from the Renewable Energy Association (REA) see a parallel to the Caribbean islands they have advised, such as Antigua and Barbuda. There, a similar reliance on diesel generation was replaced with a network of solar farms and battery banks. “In a country with over 300 sunny days per year, importing heavy oil to burn for electricity is not strategic, it’s a trap,” says James Fletcher, head of REA’s international programme. “Cuba could use distributed solar plus storage to power critical loads in each neighbourhood, including water pumps. You don’t need to replace the whole grid overnight. You build a resilient underlayer that works when the central grid fails.”
Fletcher’s team has modelled a hypothetical system for Havana: rooftop solar panels on public buildings and high-rises, combined with community-scale lithium-ion batteries. During normal hours, these would feed into the grid; during blackouts, they could island specific blocks, powering elevators, water pumps, and communications for 24 hours. The cost for a pilot in the Vedado district would be around $15 million, a fraction of the $120 million Cuba recently spent on the failed Guiteras plant repairs.
There are obstacles. The US embargo restricts imports of modern solar equipment, and Cuba’s economic crisis limits foreign currency. However, the REA notes that many UK and EU companies have no such restrictions; they just need a framework for finance. “Cuba has an acute problem and a world-class solar resource,” says Fletcher. “We are offering technical assistance to design a resilient microgrid. The political will is the missing variable.”
The Cuban government has historically emphasised centralised planning and thermal generation, but the blackouts have cracked that orthodoxy. Last week, President Miguel Diaz-Canel acknowledged that “a new energy system” is needed. Whether that shift embraces renewables or merely swaps one fossil fuel for another will determine if Cuba’s high-rise residents are freed from their vertical prisons.
For now, volunteers in Havana carry water buckets up concrete stairwells under the tropical sun. Science cannot replace those steps, but it can offer a smarter path forward: decentralised, resilient, and powered by the sun. The data are clear. The question is whether the system can adapt before the next grid collapse.
