Complex solutions for electricity supply in Cuba

Electricity supply in Cuba is going through an extremely complex moment, with very prolonged blackouts, with daily affectations exceeding 1,600 megawatts (mw) in the night peak hour. In addition to this, there is dissatisfaction due to the lack of homogeneity in the rotation of circuits or in the planning of the effects, when comparing some territories with others.

In spite of the prolonged crisis, the Cuban State and Government are working on the implementation of a strategy to gradually reduce the impact on the supply of electric service.

In the short term, this itinerary implies affectations, due to the departure of the thermal units to comply with their maintenance schedule and the lack of fuels, said Argelio Jesús Abad Vigoa, First Deputy Minister of Energy and Mines (Minem).

Strategy for the recovery of the Electric System

Lázaro Guerra Hernández, director of Electricity of Minem, clarified that the strategy adopted takes into account all generation technologies.

Although photovoltaic solar parks are far from being the main pillar, he pointed out, they have advantages such as their rapid completion and fuel-free operation.

However, when the 2,000 mw solar photovoltaic project is completed, the sum of its contribution will be below the thermal capacity lost from 2019 to 2024. Therefore, a strong work in thermoelectric power plants (CTE) is required, he said.

Today, 15 units are operating, said Abad Vigoa and, for the time being, only the recovery of Tallapiedra, in Havana, out of service due to technical failure, is not foreseen.

In contrast, there are plans to rehabilitate the Felton 2, Mariel 7, Nuevitas 4 and Renté 4 blocks, and thus incorporate 550 mw to thermal generation.

He also informed about the end of the total maintenance of the turbine – last interrupted 14 years ago -, the generator and other elements of unit 3 of the Carlos Manuel de Céspedes power plant, in Cienfuegos, although deep work on the boiler is still pending.

Its economizer, with five decades of use, has caused the last two outflows, after re-synchronizing, because the tubes, damaged by the heat, collapse, he explained.

Unit 4 receives capital maintenance on the boiler, turbine, generator and other components. This thermoelectric plant, in a traditional way, presents a high technical level and experience in its forces, with a different work culture, inherited from the installation of its Japanese technology. We consider the work carried out there as positive, said the First Deputy Minister of Minem.

Guerra Hernández said that, now, Mariel unit 6, Santa Cruz del Norte unit 2 and Renté unit 5 are receiving boiler maintenance, while Santa Cruz del Norte unit 3 and Nuevitas unit 5 are receiving light maintenance. Soon, CTE Antonio Guiteras and Felton 1 will be subject to brief work to reduce the risk of breakdowns in view of the summer. The first of them could leave again at the end of the year, for a capital service, he added.

Currently, the demand in the early morning almost equals that of the day, above 3,000 mw, he said. He specified that in thermal generation, some 1,993 mw of power are installed in the country, and it is estimated for July an availability of 1,120 mw, increased in August to 1,160 mw, said the Director of Electricity of Minem.

Other generation solutions

At the end of April, the country had 1 020 mw of power in distributed generation, of which about 200 have been recovered so far in 2025, he explained.

He added that fuel continues to be one of the main causes of blackouts and a risk factor. However, 238,000 tons have been almost secured and another 40,000 tons are being managed.

As for Energás Varadero, he said, its gas engine 3 and steam engine 4 are out of service. Their solution is scheduled for June and they would be incorporated the following month.

Several actions in the Boca de Jaruco gas wells are designed to reach the 2.3 million euros of gas production.

For the summer period, the main purpose is to reduce the average impact to four hours a day per customer. Based on the increase of generation by 13 gwh and the control of consumption growth.

The deputy director of the Cuba-Petroleum Union, Irenaldo Pérez Cardoso, provided assurance on the logistical conditions for the unloading of a ship with liquefied petroleum gas (LPG). Although the funds for its payment, which are currently being managed, have yet to be completed.

Abad Vigoa pointed out that the lack of LPG adds, on average, 1 gwh for cooking food. Blackouts also trigger consumption, due to the coincidence factor. The connection of several pieces of equipment at the same time.

When these switch on, they generate a current peak 15 times higher than their normal consumption. In addition, high temperatures lead to longer use of cooling and climate devices, he added.

From 2018 to 2024, the island imported more than 17 million household appliances and other devices that require electricity. Such as motorcycles, refrigerators, which causes a sustained increase in demand, he said.

This behavior, in turn, affects the burning of many transformers; one day last week, only in the capital, ten collapsed, said Abad Vigoa.

He stated that, although there is a level of resources in two factories established, and another to be opened this Thursday in Villa Clara. It is insufficient to replace all the damaged transformers.

The First Vice-Minister of Minem alluded, as a latent risk, to the possibility of the withdrawal of the patanas, equivalent to some 400 mw, due to the difficulties to honor their monetary commitments. In spite of the fact that a ship with lubricants for them is about to arrive.

In addition, South American nations such as Ecuador are interested in buying the floating generation to alleviate the paralyzation of their hydroelectric plants, due to the lack of water, he contextualized.

Recovery in the medium term

The recovery of Felton 2 is in the medium term, since with the national production a level of beams processed in Las Tunas is guaranteed, which will be assembled since June, by forces of the Ministry of Construction.

In addition, financing is being negotiated to import aggregates and metallic resources to produce them in Cuba.

With everything in hand, including no less than 70 million dollars, the rehabilitation of the block would take about two and a half years.

As for the photovoltaic solar parks, he said that by January 2026, 51 should already be synchronized, with a total contribution of 1,115 mw. The inauguration of four new ones will take place this month,

The energy generated in each of these spaces is equivalent to its installed power, multiplied by approximately five hours, he explained.

In general, the parks deliver between 70 % and 75 % of their capacity, due to cloud obstruction and other reasons, commented Guerra Hernández. This energy should not be compared with thermal energy, because the former varies and the latter presents stability, he clarified.

A problem of this source, when its presence in the National Electric System (SEN) increases, will be its incidence in frequency variations, capable of triggering other units.

The solution consists of installing 200 mw of accumulation, to counteract the difference in the face of fluctuations. When we reach a scenario of sufficient solar energy, part of it can be reserved for other schedules, said the First Vice-Minister of Minem.

The parks are incapable of causing a black start in other units because they have a tracking character, not a forming character. However, tests are being carried out to establish hybrid microsystems between distributed generation engines and a small part of the capacity of a wind farm. For the time being, in the event of an eventual failure of the SEN, there is an indication to open all the photovoltaic solar parks because they make it more unstable, informed Guerra Hernández.

Regarding the rotation of the blackout circuits, the operating margins in the territories and the savings of large consumers, the following will be detailed in the next edition.

With information from Granma

Translated by Aliani Rojas Fernández