Renewable energy for greenhouse agriculture

The greenhouse industry is a profitable branch in most countries of Europe. However, this sector has to limit its consumption of fossil fuel and reduce its CO2 emission, in order to respond to the European Directives on energy, energy efficiency and the environment. This paper focuses on the evaluation of the energy greenhouse demand in the different climatic areas of the Italian peninsula. An algorithm was developed on the base of the average outside data of solar energy radiation and the outside average temperatures for the different regions of Italy. Results shown that in the southern regions of the peninsula the annual electricity greenhouse demand can be fully covered by a PV solar system of 70 kWp. On the other hand, a biomass boiler calculated as 100 W/m2 can be used to cover the heating power demand of greenhouses. As average data, the power energy load calculated for the Italian greenhouse agriculture was evaluated between 30 Wm-2 (in southern regions) and more than 175 Wm2 (in northern regions), with an energy consumption ranging from 21 to 546 kWhth/m2/year.