By Gabriel Molina
Product of the experience acquired with the demonstration facilities developed and the infrastructure created in Copextel for the design, assembly and maintenance, together with the efforts of the Electronic Industry in the production of panels, the country has been able to solve numerous electrification needs for social objectives and inexpensive in isolated areas of the network.
EMIR Madruga, manager of ECOSOL, considers solar energy as the fundamental strategic element for sustained development.
"In each square meter of Cuban territory an amount of solar energy equivalent to half a kilogram of fuel oil or 5 KWh of electrical energy is received daily, an average value practically unchanged throughout the year and almost the same throughout the country," he told Granma International.
"As a result of the experience acquired with the demonstration facilities developed and the infrastructure created in Copextel for the design, assembly and maintenance, together with the efforts of the Electronic Industry in the production of panels, the country has been able to solve numerous needs of electrification to objectives social and economic in isolated areas of the network. "
Madruga reported that in Cuba applications such as the Photovoltaic Electrification Program have been made to the Family Physician's Consulting Houses in the mountains and remote rural areas, with more than 400 operating facilities, mountain hospitals, boarding schools, social circles , the more than 2 364 elementary schools where in a first stage TV and VCR equipment were installed in support of the Audiovisual Program, within the framework of the "Battle of Ideas" and in a second stage solar systems in the same number of schools to guaranteeing the work of computers, and more than 1 860 television rooms, true centers for the universalization of culture, in secondary schools and others that had unreliable services confirm the positive of this solution.
"Other recent applications have been occupying a prominent place among solutions at the international level," he added.
"There is already little progress with the electrification of some 200 homes in the most remote areas of the Yateras and San Antonio del Sur municipalities, in Guantánamo."
The ECOSOL specialist confirmed that "the applications where photovoltaic systems are the most competitive are isolated services in places where the lines of the National Electroenergetic System (SEN) do not reach. The greatest advantage of these systems is their autonomy and independence. reliability in its operation ".
"The direct transformation of solar radiation into electricity by photovoltaic conversion is one of the most widespread forms of use. Its sustained international development shows an annual growth rate of 33% in the last 5 years, at the end of 2004 there were more than 2 510 MW installed, of which almost 90% are in industrialized countries ... Under specific conditions, grid-connected systems begin to be installed rapidly. (1)
Photovoltaic systems connected to networks are being used more and more. They were initially developed for large photovoltaic plants. As the development of electronics progressed, smaller and more manageable systems began to be designed, installed in the manner of small domestic centrals, fully adaptable to homes with a conventional connection for the electricity supply of public networks. In this way, investment and operating costs are greatly reduced and your performance increased.
"The grid injection systems, as in Germany, Japan and other countries, could be an important complement for the stability of the National Electric Service, from the establishment of a program that develops this significant application in an accelerated manner in Given the wide possibilities of use, in the medium term grid connection systems should become the sector with the highest demand for PV panels.
"Hybrid systems are being widely used in remote applications due to their high reliability, minimal maintenance, little or no fuel demand and reduction in required batteries. A combination that is gaining in importance is wind-photovoltaic-Diesel. intelligent "controllers (which have evolved so much) have a wide field of application in hybrid systems.
Finally, Madruga pointed out that "a very important area in which solar energy is being introduced is transportation. In buses, with the use of hydrogen produced with solar panels and fuel cells.
Solar energy can be injected into the national grid
Another example of home electrification originated in late 2003, when Jean-Paul Robles, representative in Cuba of the Total company, the fourth international oil and gas group in Cuba, was having dinner with peasant friends in Viñales. But night came and since they had no electricity, there was only candle lighting to finish.
Total donated modules to illuminate 43 homes there with solar energy for a value of 43,500 euros. It also took charge of the transport to place it in the port of Havana, according to the agreement with the UNDP, which contributed 24,769 euros.
"On January 21, 2006, the first phase of the project was inaugurated, which had already been operational since November 2005. I announced to those attending the inauguration that my company, Total, agreed to work on a second phase of 52 houses. Because In addition to Total and the French financial company Oseor, I went to the French construction company Buygues, which makes all the hotels in my country, and obtained a budget of 15 thousand dollars for this second phase of the project.
"We can now launch the second phase, of 52 houses with a guaranteed budget of 105 thousand dollars, because we have the money and the raising of the houses, we just have to start. If there are no logistics problems, it should be finished by the end of this year 2006, "advanced.
In a process of Energy Revolution such as the one experienced in Cuba, alternative energy is important, not only because of the possibility of saving hydrocarbons that it represents, in times when the rise in oil prices makes solar energy less economically unfavorable. compared to that produced before, when oil prices were more competitive. To find out about international criteria on the subject, Granma Internacional inquired with the representative of Total.
"Solar energy can be harnessed in various ways," Robles answered, "as energy in places where there is no electrification or also as a contribution to a country's distribution network. That is, to take advantage of solar energy to charge the normal distribution network. of electricity, can, for example, be a help, a reinforcement for high consumption hours, 'peak' hours ".
"It is also applicable for saving in places where the classical system is very difficult, where the cost per kilowatt is very high. The needs are calculated by specialists and implemented, as has been the French experience in Martinique, where solar energy is cheaper than that produced by normal way.
In cases of cyclones
Regarding disaster situations, Robles thinks that solar energy is interesting to feed or produce energy in the event of a cyclone, or strong blackouts. It can be accumulated or as it is easily assembled and removable, produce it before or after the atmospheric phenomenon without major problems and dangers.
"It is possible to power the light from the lamps and bulbs of any building with solar energy, for example, in a hospital, to supply emergency equipment and equipment.
"Without a doubt, the entire system of the hospital or other building could be made to work, he said. You have to do the calculation, multiply the number of panels according to all the consumption needs of the building in question, to the full power required. "
In relation to costs, the representative of Total pointed out that compared to an oil-fired plant, perhaps the investment at the beginning is larger, but it does not need fuel, it is safer and cleaner. In the case of Viñales, he stated that counting the lighting and access to modern means of communication, television and radio-recorder, which were included in the module, the cost was USD 1 925 per dwelling. •
Grid-connected photovoltaic systems
A photovoltaic system connected to the grid basically consists of a photovoltaic generator coupled to an inverter that operates in parallel with the conventional electrical grid. The grid injection concept has a wide range of applications, from small systems with a few kilowatt peak (kWp) installed power to plants with several megaWatt peak (MWp). The photovoltaic generator captures solar radiation and transforms it into electrical energy, which instead of being stored in batteries, as in isolated and hybrid systems, can be used directly for consumption or delivered to the electrical distribution network. These two functions are performed by a direct current to alternating current inverter specially designed for this application. The photovoltaic generator or panel field can be integrated into roofs or facades in homes and buildings, or in special structures.
Among the main advantages of these systems, the following can be mentioned: losses in transmission (8-12%) and distribution (16-22%) of electric power are eliminated. They are easily and quickly installed on any building or parking area well exposed to the sun and without obstacles or nearby buildings that cast shadows, without consuming more space than the building already occupies in the urban environment. They do not produce pollution or harmful effect. They are modular systems: they allow investments progressively. Operation and maintenance costs are incomparably lower than thermoelectric plants. Most of the photovoltaic panels produced today are connected to the grid, from solar roofs and facades with powers of a few kWp to solar power plants with tens of MWp. Thanks to their flexibility, they represent enormous potential for the energy industry.