According to Xinhua News Agency, the Cuban Electric Power Union reported on the 3rd that at 5:05 PM on that day, the country's power system experienced a complete power outage. This is the second national power outage in Cuba within 24 hours.
Cuba is facing not just a power outage, but also it has become extremely difficult to even "restart" the electrical grid.
On the evening of August 1st local time, two 220-kilovolt transmission lines connecting Martinas and the central region failed simultaneously, causing power outages in five western provinces of Cuba. The affected population accounted for nearly half of the country’s total population. Repairs were completed early the next morning, but just one day later, the entire national power system in Cuba was completely disconnected around 11 p.m. on the 2nd, plunging tens of millions of people into darkness.
A more serious incident occurred on the 3rd. The Cuban Electric Power Union initially used small power sources to establish local grids, gradually restoring power to hospitals, communication facilities, and some residential areas. For a while, about 23% of Havana's area had power restored. However, in the afternoon, a power fluctuation combined with bad weather damaged the power transmission network, causing the generators that had been connected to the grid to shut down again. The entire system was forced to start the restoration process from scratch.
Cuba experienced two nationwide power grid failures in less than 24 hours. Different media report on whether the restoration failures should be counted separately, so it is referred to as the sixth or seventh national power outage this year. However, what is more alarming is that in July alone, Cuba experienced three nationwide failures within nine days.
Technically speaking, the weather is just the last straw.
After a national power grid fails, large-scale power plants usually cannot start on their own. Emergency repair workers must first rely on gas units, hydropower, diesel generators, etc. to create separate 'power islands', then supply electricity to the large power plants, start each unit one by one, and finally re-synchronize all areas.
At this stage, the power grid is small in scale and has low reserve capacity; both frequency and voltage are unstable. Normally, the primary lines can be absorbed by backup units. However, when these lines trip, it can trigger a chain reaction: the power transmission network becomes unstable, protective devices of the units are activated, and online power sources withdraw from service one after another. The power grid, which has just been re-established, falls apart once more.
The problem is that even under normal operating conditions, the Cuban power grid has very little reserve capacity. Before this accident, the Cuban power system had only 895 megawatts of available capacity, while the demand reached 2825 megawatts. Ten thermal power units were shut down due to faults or maintenance work. In other words, the system was not only operating at full capacity, but was also barely maintaining operation under prolonged power shortages.
There are three main dilemmas behind this situation. First, many of Cuba’s power plants have been in operation for decades, resulting in frequent malfunctions and aging transmission facilities. Second, a lack of foreign exchange and spare parts leads to delays in maintenance work. Third, and most directly related to the current issue, is the depletion of fuel supplies. Cuba needs more than 100,000 barrels of oil daily, but it can only produce about 40,000 barrels domestically, with the rest having to be imported. Traditional supply channels such as Venezuela and Mexico are clearly shrinking.
Havana attributes the crisis to U.S. sanctions that have reduced access to oil, financing, and equipment imports; Washington, on the other hand, points to insufficient long-term investment in Cuba and the inefficient state energy system. Both statements are not completely contradictory: external blockades have taken away fuel and funds, while internal problems have left the power grid unable to withstand shocks.
The cost of power outages has affected water supply, food refrigeration, hospitals, public transportation, and communication systems. In hot and humid weather, some residents of Havana even have to sleep outdoors on the coastal roads to cool down.
Therefore, the energy crisis in Cuba is undergoing a qualitative change: in the past, the issue was 'how much electricity to generate'; now, the issue is 'whether the power grid can continue to operate smoothly'. As long as backup generators, energy storage systems, transmission redundancies, and stable fuel supplies are not restored, even rekindling Havana does not mean the crisis is over. The next thunderstorm, a malfunction of one of the generators, or even a normal fluctuation during the restart process could bring the country back to zero once again.
