Wood Biomass as Sustainable Energy for Greenhouses Heating in Italy

The Italian greenhouse vegetable industry is an important sector that requires thermal energy as much as 0.74 Mtoe, derived mostly from fossil fuels, which corresponds to 2 MtCO2 emissions. The Energy Strategy 2020 of the European Commission calls for increased use of renewable resources in the energy system, thus pushing the technology of wood biomass system for space heating of the greenhouses, since this resource is considered as ‘greenhouse gas’ (GHG) neutral when converted to heat, excluding the GHG generation during harvesting, transportation, and pre-processing of raw materials. Taking into account the different climatic areas in the Italian peninsula, power energy load was estimated to be between 30 Wm-2 (in southern regions) and more than 175 Wm-2 (in northern regions), while the energy consumption was estimated in the range from 21 to 546 kWhthm-2year-1 according to different internal air temperatures. Moreover, the CO2 enrichment in greenhouses from the exhaust gas of a biomass heating system can bring benefits for greenhouse plant production, along with optimal management strategies to reduce fuel consumption. Unfortunately, CO2 enrichment from the exhaust gas of biomass boilers is still challenging and expensive, considering that wood biomass boilers generate a higher volume of particulate matters (PM) and ash emissions than other fossil fuels. However, wet scrubbers and other recent flue gas conditioning devices could help to reduce costs and make this process more feasible. Thus, a techno-economic assessment is highly recommended to ascertain the economic feasibility of wood biomass boilers for the greenhouse industry. Finally, some economic considerations are provided to make cost-effective use of the solid biomass in relation to the economic incentives by the National Decree of 28 December 2012, so-called “White Certifies”.