Croatia’s example of good practice in biowaste management: creating value, protecting the environment

Croatia has gone further than any other country in the region in biowaste management and treatment, but the EU’s youngest member is still at the beginning of the journey considering its overall potential in this field. Suppose Croatia were to utilize its biowaste potential, of 400,000 tons entirely. In that case, it could produce 104 GWh of electricity a year, equivalent to 7.3% of the country’s total 2021 power output from renewable energy sources, Marko List, CEO of ConsultAre, a Croatian company that is making great strides in biowaste management, says in an interview with Balkan Green Energy News.

With the energy crisis in full swing and countries scrambling to secure energy supplies, biowaste seems to be misguidedly left out of mainstream deliberations on green energy and climate solutions. Biowaste could play a significant role in the production of clean energy from domestic sources, given that it makes up 30-40% of all municipal waste in Europe and that responsible biowaste management reduces emissions of methane, a gas that affects climate change 20 times as much as CO2.

Looking for examples of good practice in the region, Balkan Green Energy News has found one in Croatia. So far, the country has installed six facilities for processing biowaste into raw material for biogas plants that produce electricity and heat.

Biogas power plant in Croatia (photo: ConsultAre)

Although Slovenia and Hungary have one such facility each, Croatia leads the way by the number of installed facilities. This achievement, as with most new technologies, is due to six years of effort and enthusiasm of Croatian firm ConsultAre, the leader in this part of Europe in biogas consulting and the distribution of biowaste treatment technology and equipment.

Croatia has been treating biowaste for ten years

Croatia made its first baby steps in the utilization of biowaste in biogas plants, alongside their traditional raw materials such as corn silage and animal manure, back in 2012 and 2013, according to ConsultAre CEO Marko List. This included regular biowaste, but also food from restaurants, hotels, supermarkets, and farmers’ markets, he explains.

Collection of biowaste in Croatia (photo: ConsultAre)

In 2013, as the newest member of the EU, Croatia adopted a law on sustainable waste management in line with the European Waste Framework Directive, setting a 50% target for waste recycling by 2022. Some cities and municipalities took this goal seriously, and the target has so far been met by Osijek, Prelog, Krk, Koprivnica, etc.

“In the beginning, when most of the biowaste came from restaurants and hotels, it didn’t contain impurities, such as plastics, glass, metal, and so on. However, when cities and municipalities started collecting biowaste separately and took an interest in biogas facilities, they faced the problem of how to remove impurities. So in 2019, the first device was installed at a biogas plant, and it proved to be a great success, overcoming the challenge of impurities with ease,” List explained.

Biowaste management reduces municipal waste and brings financial gains

Managing biowaste is important for several reasons. This process is, as List says, a “combination of different factors,” but it is clear that everyone can benefit – some by cutting costs, as is the case with utility companies, and some by making a profit.

Biowaste management in Croatia (Photo: ConsultAre)

As for cutting costs, the separate collection and treatment of biowaste reduces the amounts of municipal waste, as required by the EU, enabling cities and municipalities to bring down the fees they pay to the state for not meeting the targets, according to List. Also, both public and private utility companies in Croatia are looking into ways to make a profit from biowaste management, not just cut costs, and one utility company has already purchased a biowaste treatment machine, he says.

On the other hand, the private sector has spotted an opportunity to make a profit by treating biowaste and selling raw materials to biogas plants. Amid rising costs of their core raw materials, biogas plants are seeking to diversify supplies and find new raw materials.

Available data shows that 1 metric ton of biowaste yields an average of 130 cubic meters (m3) of biogas with 55-60% methane content, while the production of 1 MWh of electricity requires about 500 m3 of biogas – which translates into 1 MWh of electricity from about 3.8 tons of biowaste.

When it comes to heat, List explains that 1 m3 of biogas produces 6 kWh of heat, which means that 1 ton of biowaste produces 780 kWh of heat.

Biowaste treatment requires state-of-the-art machines

Under EU and Croatian law, producers are liable for the management of all expired packaged food in supermarkets, which compels producers whose business does not include waste management to pay specialized private companies to do the job.

Before the Netherlands-based company Mavitec rolled out its depackers, machines distributed in the region by ConsultAre, expired food was depackaged manually, which was very costly and slow. The use of Mavitec systems has sped up the process, making it cheaper and more competitive, according to List. This technology, he explains, is equally effective in the treatment of municipal biowaste, restaurant biowaste, and biowaste generated by the food industry.

Paddle Depacker technology for biowaste processing (photo: ConsultAre)

A big problem in biowaste treatment is the content of impurities, which make up some 20-25% of household biowaste in Croatia.

This, according to List, is a result of insufficient efforts on the part of utilities to educate customers and raise awareness, but also negligence on the part of some customers, who simply don’t want to separate their waste. List has recently published an article on this topic to help address the problem.

The CEO of the pioneering firm in biowaste management in Croatia also explains that the machine, called Paddle Depacker, very effectively separates all impurities from biowaste and other organic waste, as well as packaging from expired food. The secret to the machine’s effectiveness is in its special, fast-spinning paddles and screens, which separate packaging from organic material. The purity of organic soup, the final product of biowaste treatment, is as high as over 99.5%, and its quality is verified through analyses conducted in laboratories in Austria and Germany. These analyses are necessary so that owners of biogas plants can be certain that the new raw material is compatible with their technology and compliant with the standards.

The device comes in two versions – one with a capacity of 5 m3 per hour and the other with a capacity of 30 m3 per hour.

City of Osijek leads the way in waste management

The Croatian city of Osijek is a good example of commitment to waste management, including biowaste. In 2021, the city has separated and collected 51% of all generated waste. However, the case of Osijek also illustrates the serious challenges in establishing a system and ensuring that citizens continuously separate waste. Although Osijek had a history of good performance in waste management, it took several years of preparations and education for the city to secure the necessary infrastructure, build a biowaste treatment facility, and ensure cooperation of the public utility and citizens.

“Osijek is a commendable example – cooperation between the city authorities, politicians, the public utility, and citizens in action,” says List.

Great potential of biowaste for electricity generation

ConsultAre has conducted an analysis demonstrating the great potential of the utilization of biowaste in energy production in Croatia. The untapped potential of 400,000 tons of biowaste could be harnessed to generate 104 GWh of electricity a year, equivalent to 7.3% of Croatia’s 2021 power output from renewable sources.

Currently, there are 42 biogas power plants in operation in Croatia, with a combined capacity of 47.9 MW, but only 11 of them used biowaste last year (slightly over 17,000 tons). The potential is immense, but the lack of the raw material collected by utility companies remains the greatest challenge given that, according to official data, biowaste is not collected separately in 61% of Croatian cities and municipalities.

List also explains that larger cities and municipalities should certainly consider building their own biogas plants. According to him, Zagreb intends to build a composting plant and a biogas power plant that will treat biowaste collected in the Croatian capital.

The city of Novska also plans to build a composting plant and a biogas power plant, with an annual capacity of 60,000 tons of biowaste. The investment, valued at EUR 50 million, will be financed from EU funds through a public call for the construction of facilities for the treatment of separately collected biowaste, part of Croatia’s National Recovery and Resilience Plan 2021-2026, he says.

Eligible to apply are small, medium, and large businesses, while subsidies will cover between 35% and 80% of investment in facilities for biological treatment and separate biowaste collection. “Besides addressing the problem of biowaste and turning expenses into revenues through investment, cities and municipalities would also be able to make a positive impact on the economy as a whole, and the environment, by selling electricity, and, in the future, biogas, heat, and digestate fertilizer,” says List.