Powerships carry their own generator fueled by oil or gas, anchor close to land and connect to the local electricity grid. They are leased by the host country.

The energy crisis, with blackouts in 4 to 6-hour-blocks twice daily or more in most of the country, is perhaps the most painful symptom of a deeper financial crisis caused by external factors such as U.S. sanctions, the COVID-19 pandemic and poor economic management.

Cubans are also living through food, medicine and fuel shortages, forcing them to wait in long lines for the basics.

Cuban power plants are obsolete, averaging 35 years of age, with a backup system of hundreds of smaller generators at least 15 years old. Just 5% of power comes from alternative energy sources.

The government blames lack of funds for its inability to update its decrepit grid, and says breakdowns, not fuel shortages, are the main cause of blackouts.