Kalundborg: when one company’s resource works for another

Industrial symbiosis in Europe is not merely a theoretical experiment. Kalundborg has developed it for more than 50 years through contracts, infrastructure, data and trust between companies.

The core principle of Kalundborg Symbiosis is simple: one company’s residual stream can become another company’s resource. It may be heat, steam, water, biomass or a material. An exchange proceeds only when it is technically feasible and creates economic and environmental value.

The network began taking shape in 1961 with a surface-water pipeline. Kalundborg dates the industrial symbiosis itself to 1972, when surplus refinery gas began to be used by a neighbouring producer. The system was not designed in one step; it grew through individual commercially justified agreements.

Partners now exchange energy, water and materials. Surplus heat supports local district heating, surface water reduces demand for potable groundwater, and residual biomass becomes biomethane and fertiliser. The local utility operates more than 30 km of pipelines between participants.

According to figures published by Kalundborg Symbiosis without a separate measurement year, the system saves about 4 million m³ of groundwater, avoids 586,000 tonnes of CO₂ and reuses 62,000 tonnes of residual materials annually. These are Kalundborg results, not a forecast for another park.

An assessment based on 2015 data estimated combined business savings at DKK 182 million per year and socio-economic benefits at DKK 106 million. These are modelled savings versus a scenario in which the companies operated separately—not current cash revenue or a public subsidy.

For BRIL PARK, Kalundborg matters as a method. Resident screening should consider water, heat, materials and by-products alongside land and electricity. Every proposed link still requires data, CAPEX analysis, contracts, permits and a backup supply route. Kalundborg is a global benchmark, not an automatic outcome for every European park.