Since 2017, the Notranjska Regional Park has been exploring ways to make use of the grassland and reeds that remain as dead biomass on Lake Cerknica every year. During this time, several experiments have been carried out on energy utillisation and the use of biomass as raw material for paper production. Both uses have proved to be possible but not economically viable. As part of the LIFE TRSCA project, we are already running a composting trial to see if this use is viable.
Production line in Halberain (Photo: archive www.pelletierung.at)
In November 2016, the first international pellet centre opened in Halbenrain, Austria, to reuse as much of the "leftovers" from agricultural production as possible by creating new biomass products. The centre promotes the reuse of biomass to replace fossil fuels such as petroleum and fuel oil. In early October 2024, LIFE TRŠCA staff visited the centre to meet Gunter Weiß, President of the Austrian Pellet Association. Mr Weiß started producing feed pellets from hay from Austrian nature conservation areas back in 2010. During our one-day visit, we also met with Dr Andreas Breuss, representative of the nature conservation area manager of Styria, and Dr Alfred Kindler from the government office in Graz.
Günter Weiß has been engaged in pelletisation since 2010. (Photo: archive Landwirtschaftskammer Steiermark)
On a visit to Halbenrain, we test-delivered a few kilos of dried grass from Lake Cerknica to try out pellet production. The first measurements were very encouraging, showing that it is possible to produce pellets for bedding or animal feed from the grassland of Lake Cerknica. However, it is important to point out that the grassland must be properly cut to produce pellets. A single dried grass straw in a bale must not exceed 20 cm in length. The grass for pelletizing must also be extremely dry, which means that the moisture content must not exceed 15 %.
Wheat straw litter pellets
Experts from Austria agreed that, given the long duration of the annual flooding of Lake Cerknica, the quality of the grassland and the moisture content, most of the dead biomass is likely to be the most economically viable for compost production. The Halberain experts have also concluded, after various tests over several years, that maize cobs are the most suitable for the production of heating pellets made from cultivated plants, as they have a similar calorific value to woody biomass. In the coming months, we will therefore deliver 1 tonne of grassland to Halberain to be produced into litter pellets on a trial basis, as part of the LIFE TRŠCA project. These pellets will later be repackaged into small 2 kg bags and distributed free of charge to local residents to evaluate and price the product.
The aim of the Notranjska Regional Park is that this project action of experimental utilisation of plant biomass from the lake for pelletizing and composting would encourage private companies to invest in a plant that would produce a value-added product from the biomass. The idea promises a long-term solution to the problem of removing and utilising biomass from the lake and offers an opportunity and a chance for the private sector of the economy. If the pelletization experiment is not suitable due to the higher humidity of the plant biomass materials on Lake Cerknica (drying of the material is a time-consuming and also energy-inefficient process), we will follow the advice of Austrian experts and switch to compost production only.
