| Popis: |
The development of energy policies aimed at reducing energy consumption and the environmental impact together with the importance of the agricultural sector and its associated industries in certain regions, such as Extremadura, where most of the agricultural production is carried out by traditional cultivation systems, makes that the use of land that is not naturally suitable for crops and get a productivity improvement thanks climate control through renewable energies in greenhouses it and interested proposal. So, the purpose of this work is assist small farmers in obtaining the fruits demanded by the market, through the use of renewable energies and the use of soils that are not very favourable for cultivation, contributing to achieve an economically profitable and environmentally sustainable agriculture. The intervening factors are the outdoor climate throughout the year, the interior requirements for the crop-sequence and the covering greenhouse with auxiliary energy supply, it's possible estimate the energy demand throughout the year and the contribution of each source to this demand, contrasted with a practical case study in Extremadura. The estimated result for this case it is an energy demand of 9 GJ/m2 with 62 % covered by solar radiation, 33 % by natural ventilation systems, 3 % with refrigeration and 2 % covered by heating. An economic analysis of the operation is included, taking into account the main intervening factors. In conclusion, thanks to greenhouse cultivation, by means of current fertigation systems that allow the use of the most suitable solution to be added to the irrigation water it is possible to cultivate in unsuitable soils, controlling the humidity and components present in them, as well as the tension generated by the roots of the plants. The energy demand is satisfied by solar radiation and ventilation mostly, which are renewable sources of energy, by making the contribution of heating by local biomass is covered almost entirely by renewable energy sources. |
