The future of clean energy passes mainly through forests. And not just because the forests, through their thick vegetation, release oxygen and capture carbon dioxide (they absorb 30% of that emitted), making a decisive contribution to reducing its concentration in the atmosphere and fighting global warming. And not just for the use of wood to build houses: a cubic meter of wood locks up 1 ton of CO2 (while a cubic meter of concrete releases 2,5). A wooden house therefore saves about 50 tons of CO2: in Europe, 10% more houses built in wood would be enough to emit 25% less carbon dioxide (buildings and the construction sector are responsible for the 39% of all CO2 emissions in the world).
But there is also a utility that not many people know about: the biodegradable part obtained from the maintenance of the woods (and from the organic residues of agricultural and agro-industrial activities) constitutes solid biomass and therefore clean electricity can be obtained from it. This is dealt with by the EBS association (Energia Biomasse Solide), which represents the main producers of electricity from solid biomass and brings together 20 operators and 23 plants larger than 5 MW (therefore in this case we are not talking about wood transformation in pellets, but of a thermal process that produces electricity through the combustion of wood) throughout the Italian territory. This activity, which also employs over 5.000 workers considering related industries, generates electricity for over 3.000 GWh, with 420 MW of installed power and using about 3,5 million tons of solid biomass per year, of which over 90% produced in Italy.
Forests play a central role in this process. “Residues from authorized forest maintenance – confirms the president of EBS Antonio Di Cosimo – constitute the main source of fuel, accounting for a percentage that exceeds, on average, 50% of the total quantity used”. Various sector studies also show that in Italy the area occupied by forests is three times as much as in the early 1990s of the last century. In ten years, between 2010 and XNUMX, the surface of forests in Italy has increased by almost 20% while in the European Union the increase was, for the same period, 5% (data from Global Forest Resource Assessment 2010). But despite this, the availability of biomass for energy use is largely underused in Italy: between 2000 and 2010 in Italy there was a 23% reduction in the average withdrawal data per unit area.
“The development of a regulatory framework aimed at its valorisation has been lacking, also held back by intellectual particularisms sometimes born of a lack of knowledge of the subject – explains Di Cosimo -. In the last two decades, much has been done by the private sector to promote and develop companies or groups of them that were specialized in the correct management of this important resource, always guided by the principles of lawfulness and circular economy, in a "win-win" logic ”: this is demonstrated by the fact that even public bodies were able to ascertain the goodness of the results achieved”. The results speak for themselves: thanks above all to forest resources, today the solid biomass sector it accounts for more than 15% of renewable production and for over 5% of the total production of electricity in Italy. “But even if we only consider a 50% increase in available basins, in correlation with a regulatory framework that encourages plants like ours, the resulting green energy production could cover the national annual requirement, in theory, even up to 5.000 GWh”, adds Di Cosimo. To give a parameter, 5.000 GWh is the energy produced in 2013, at national level, from urban waste, equal to covering the annual needs of a city like Bologna (Terna 2019 data).
Not to mention the obvious benefits of an activity which, if suitably regulated, would be programmable, contributing to the stability of the national electricity grid and to maintaining a balanced energy price. "Unlike other renewable sources (such as wind and photovoltaics, ed), which are subject to specific climatic conditions that are difficult to predict in the medium-long term", argues the president of the EBS association. One last thing remains to be understood: how do you use wood without damaging the forest? “We are talking about degraded wood or wood of inadequate size for other uses: tops, prunings, wood from explants or from cleaning and adjustments or by-products such as sawmill residues. All materials which otherwise, due to the need for disposal, would constitute a problem and often a cost for the community and which instead transform a resource according to the principle of the circular economy".
The main operations for the withdrawal of forest biomass for energy purposes, entering the technical field, include both silvicultural interventions in forests governed by high forest, i.e. those in which the trees are left to grow (through the withdrawal of minor assortments, commonly left in the forest , following interventions of cutting of the major forest ranges), and interventions in woods governed by coppice, i.e. those where the trees are periodically cut. An additional source of supply is constituted by the woody material deriving from interlayer cuts, or by the interventions applied to the young high forests or to the high forests in the process of reconstitution to increase their stability and increase their production of value.
“Operations of this type – Di Cosimo points out – are obviously specialist: consequently they can be performed correctly carried out only by qualified and recognized companies also institutionally, directly or through business networks that enhance the entire supply chain. This brings significant further advantages related to the employment of labor resources”. The forest maintenance activity therefore generates: production of clean electricity, employment, tax revenue but also prevention of the risk of uncontrolled and illegal fires of abandoned material, as well as active protection against hydrogeological instability.
