In order to tackle the problem of extreme temperatures in places like Mexicali , a group of specialists from the Polytechnic University of Baja California (UPBC) has created a system of air conditioning greenhouses by means of geothermal energy , obtained from heat in the subsoil.
The system was put to the test in the university. The plants were kept at the same temperature throughout the day, so the crop period was reduced by 50 percent .
The plants and fruits grew more than they would have in an unheated greenhouse and the project offers a level 4 performance coefficient , that is, for each electric kilowatt invested, four thermal kilowatts are produced .
Abelardo Mercado Herrera, an academic from UPBC and technical manager of the project at the Mexican Center for Innovation in Geothermal Energy
, which was financed with resources from the Energy Ministry and the National Council of Science and Technology , told the news agency that a prototype greenhouse similar to a commercial greenhouse had been implemented for the development of the new system.
This one is 1,100 square meters in size, of which 200 square meters are heated, alternating between cucumber and tomato crops .
The soil of Mexicali is suitable both for agriculture and for the use of geothermal energy with low enthalpy
, because phreatic mantles and clay soils can be found only two and a half meters from the surface, making it ideal for this type of technology.
Based on these characteristics, Abelardo Mercado claimed that any farmer in the territory could implement the air conditioning system, as they verified it when installing it at the university.
The benefits of maintaining a constant temperature in crops that alternate between tomato and cucumber were that productivity increased by 40 percent, plants grew by another 1.5 meters, the number of fruits was between 30 and 40 percent higher, and also the weight of the fruits increased .
Of all the advantages obtained in the heated greenhouse, the most important was the reduction of 90 to 45 days in the period of development to obtain the harvest.
He said that this closed system is comparable to the radiator of a car, once it is supplied with water it is no longer necessary to extract it or supply more, but it circulates and its operation happens with electrical energy, an investment that is recovered and multiplied with the production of geothermal energy.
The project to heat greenhouses began in 2014 as part of the research promoted at the national level by the Mexican Center for Innovation in Geothermal Energy (Cemie-Geo) and since then it has received financing for between six and seven million pesos .
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