Home-made leaf pellets - a partial solution to the pellet shortage?

The fact that there is a shortage of pellets has not escaped anyone. At the same time, many are surprised that the wood-exporting nation of Sweden can have a shortage of wood pellets. According to several experts, the solution may lie in pellets made from ordinary autumn leaves.

The complexity is great and for many pellet producers it is a time of crisis, reduced demand for expensive sawn timber reduces the supply of sawdust that is the basis of commercial pellet production. In addition, about twenty per cent of the supply disappeared when sanctions were imposed on Russia and Belarus at the beginning of last year, covering both raw materials and finished pellets. At the same time, demand for cheap energy increased in the wake of the war, accelerating hoarding behaviour in society. A major Swedish producer of around 800 tonnes of pellets per month says that 25% of their production is exported, mainly to Denmark, but also to Norway, Germany and Poland.

Wood pellet prices are between SEK 6 and 8 per kilo. That's a big increase. Although the supply has become slightly more secure. In an article in Dagens Industri from 12 October 2022, Henrik Brodin, Head of Energy at Södra Skogsägarna, said that the price in northwestern Europe is three times higher than last year.

Research is moving forward

Researchers at SLU point out that new raw materials for pellets are needed to secure production when demand from private customers increases, but also for the environment. The research has mainly focused on so-called GROT and energy wood, which is believed to have a cooling effect on the climate compared to sawmill waste. The fact that research at SLU has not focused on pellets made from readily available raw materials is simply explained by the fact that there must be realistic commercial incentives for large-scale producers. 

The Dutch Hanze University in Groningen, on the other hand, conducted research on leaf pellets, concluding that pellets made from European autumn leaves had equivalent properties to wood pellets in terms of energy content, the sulphur, nitrogen dioxide and hydrocarbon content of the combustion gases being in some respects more satisfactory than commercial wood pellets. The only measured drawback was that the leaf pellets produced slightly more ash, similar to Swedish class 2 pellets which are around 1.5 per cent. Something that may require a little more manual labour for burners without automatic ash removal.

Another Dutchman who has done his own research on leaf pellets is Frank Dijkstra. According to him, millions of tonnes of autumn leaves fall in the Netherlands every year. An energy resource that is completely wasted. At the same time, the Netherlands imports 16.4 million tonnes of pellets from Canada and the United States. Dijkstra's thesis is that leaves harvested annually allow us to avoid cutting down forests for wood pellet production and, above all, virtually everyone with a garden can make their own pellets with the right equipment. Either as a supplement to purchased pellets or other heating systems, or to completely phase out the household need for commercial wood pellets. Dijkstra himself had a visit from Dutch TV where he shows how simple the production actually is. The leaves are raked and collected, then fed into Dijkstra's pellet press, which produces around 100-150 kilos of finished pellets per hour. The pellets produced are burned in his pellet burner. Dijkstra's own research has led him to patent leaf pellets in the Netherlands. Whether this will influence other Dutch people who want to make leaf pellets is not clear, but one thing is certain. The potential of this alternative raw material is great, especially from an economic point of view, but also from an environmental perspective.

Sweden next in line?

In Sweden, there is a lack of knowledge about the economic incentives that underlie the fact that many households on the continent produce pellets at home. In a way, making your own pellets is like chopping and stacking firewood, a natural activity for most people with a fireplace and stove. However, wood prices have also risen in the wake of the war and more and more people are choosing to buy a pellet basket for a few hundred dollars that can turn any stove into a pellet burner. This development is therefore necessary, even here in Sweden.

It is not surprising that research takes a long time and perhaps focuses on larger solutions with a commercial focus; Sweden obviously needs commercial production of pellets, regardless of the raw material. Commercial production of leaf pellets is difficult to make profitable because of the quantities required and thus the difficulties in collecting in the order of 100 tonnes of leaves a week. For private individuals, however, the situation is different. Everyone with a residential plot, large or small, rakes leaves in autumn. These are disposed of at recycling centres or burnt in barrels on the site. A pretty big waste of resources.

With an in-house pellet press, pellets can be made from leaves or other suitable materials at an energy cost of as little as 10 cents per kilogram of finished product, compared to 6-8 SEK per kilogram for purchased wood pellets. It is therefore relevant in times of economic turmoil, wars and recurring shortages to consider the possibilities for each individual household if leaf pellets can help to phase out commercial pellets and thereby significantly cut household energy expenditure. According to Svebio, heating of Swedish households accounts for 80 per cent of total household energy needs.

Sources
https://www.slu.se/institutioner/energi-teknik/projekt/logistik/nya-ravarukallor-for-pelletsproduktion-/
https://www.osti.gov/etdeweb/biblio/21411618
https://www.di.se/nyheter/en-perfekt-storm-pa-pelletsmarknaden/
https://www.svebio.se/press/pressmeddelanden/bioenergi-gor-sverige-mindre-sarbart-energikrisen/
https://dvhn.nl/drenthe/Bladafval-als-biobrandstof-21744523.html