It is credible that with one biomass boiler is it possible to heat a greenhouse while saving up to 60% on the cost of the energy carrier? Yes, if the comparison is made between an old oil heating system and a very modern one plant powered a biomass.
Perhaps the savings are a little less if the biomass boiler we compare more modern technologies (perhaps with methane gas) but we can confirm one thing: the biomass plants they are very interesting for companies in the horticultural sector. Also due to the 'proximity' to the combustible raw material, which most often is woody biomass, as well as for the undoubted environmental advantages.
According to ISTAT data, today in Italy there are 42 thousand hectares of greenhouses. The installations referable to the horticultural sector cover 37 thousand hectares, mostly in the Northern regions. The need to heat structures in the cold season is a serious problem for greenhouse growers and is exacerbated by the fact that the northern areas with high density of greenhouses are poorly methanized.
Reason why, in the greenhouse sector, the reference fuel is diesel. While the use of biomass fuels is still scarce as defined by the Consolidated Environment Law Decree 152-2006:
- plant material produced from dedicated crops;
- plant material produced by exclusively mechanical treatment of non-dedicated agricultural crops;
- plant material produced by silvicultural interventions and pruning;
- plant material produced by the exclusively mechanical processing of virgin wood, virgin wood granules and waste, logs, not contaminated by pollutants;
- plant material produced by the exclusively mechanical processing of agricultural products;
- de-oiled olive pomace.
The most common forms of biomass fuels available on the market and used for the operation of a biomass boiler are: wood logs or logs, briquettes, wood chips, pellets (technical data sheet 40E). The qualitative classification of solid biofuels in Italy is contained in the technical specification UNI / TS 11264 'Characterization of firewood, briquettes and wood chips'.
Types ofwoody biomass boiler starting from a few kilowatts, suitable for the domestic heating of single rooms or small housing units (the classic pellet stoves), up to large systems with power higher than megawatts, used for heating large users, district heating networks for the production of heat for industrial use.
From the point of view of CO2 emissions, the balance of the woody biomass can be considered neutral (as proposed by the technical data sheet 40E) on the basis of the technical consideration that the CO2 emissions from the biomass burned are equal to the amount of CO2 used for the photosynthesis process during the growth of the plant.
The situation is different for the different traditional fuels traditionally used for heating greenhouses, whose CO2 emissions are estimated at: 80-100 kg / MJ for coal, 75 kg / MJ for diesel, 65 kg kg / MJ for propane and 58 kg / MJ for natural gas.
From an economic point of view, the energy requalification of an old fossil fuel system with the installation of a biomass boiler it can be tackled even without incentives. There are ESCos (Energy Service Companies) able to develop an ad hoc proposal and 100% finance the purchase and installation of the biomass boiler, against the sharing of savings. The return on investment period can be calculated over five years.