The modern economic system is a take-make-waste linear model: we take raw materials, make something that can be sold on, and then let it go to waste. It’s the reason plastic is littered across almost the entire planet and why landfills are filling up so rapidly to the point we’re running out of space for them. Capitalism in its current form requires that this process continues for growth, regardless of the social and environmental consequences.

Transitioning to a circular economy is the start to addressing some of the consequences of the current system. We can change the way we look at waste products, whether that’s energy, water or waste material. Waste in one form can be a resource still be a resource. Take food waste for example. We consume the food and then compost any waste that becomes nutrient-rich soil that helps to grow more plants in a continual cycle.

It’s not too difficult to do it on a small scale. We can all work on the amount of waste we produce ourselves and in our own homes by reducing, reusing and recycling but there are much greater challenges across a much broader scale. However, the Kalundborg Symbiosis based in Denmark is doing just that.

The Kalundborg Symbiosis is something I came across about a month ago when reading Cradle to Cradle by William McDonough and Michael Braungart. Before that I’d never heard of it. It isn’t a particularly new concept either. The first example of a symbiotic project was back in 1961 when a pipeline funded by a public-private partnership between the Equinor Refining Denmark refinery and Kalundborg Municipality but the first truly symbiotic exchange took place in 1972.

Almost half a century later, the symbiotic relationship has grown and is thriving.

The Kalundborg Symbiosis Today

Today, the Kalundborg Symbiosis is made up of six private, industrial organisations and three public sector organisations. Every organisation is connected. They share water, energy and waste streams, as shown in the diagram below, with the vast majority of streams remaining within a closed loop system. There are some materials and waste types that are not yet part of a closed loop within the symbiosis, however, but there is a goal of implementing ten circular economy projects by 2025 that will continue closing loops.

Stream transfers in the Kalundborg Symbiosis (Source:

An example of the symbiotic relationship, and the inspiration for the Kalundborg Symbiosis logo, is the exchange of high temperature steam from Ørsted’s combined heat and power plan to many of the other partners in the Symbiosis through distinctive green pipes. This exchange also led to an alteration to Ørsted’s business plan. Originally they were producing energy with excess steam being a by-product that went to waste. However, the steam has now become the primary product and comprises a lot of their income.

Collaboration is at the heart of the success of the symbiosis. Decisions made at each company consider the impact of those companies within the Symbiosis as well as for Kalundborg as a whole. Each partner within the Symbiosis has a member on the ‘Kalundborg Symbiosis’ board to help ensure the impacts of any changes to each company are considered whilst also driving future innovation that will continue to improve the symbiotic relationship between each company.

A lifecycle analysis of the symbiosis shows just how successful the Symbiosis is with the savings results below measured on a yearly basis.

  • Savings of €24million from the bottom line
  • €14million in socio-economic savings
  • 635,000 tonnes of CO2
  • 3.6million cubic metres of water
  • 100GWh of energy
  • 87,000 tonnes of materials

A Blueprint for Industry

There are a number of reasons why the Kalundborg Symbiosis has been so successful, but a lot of it comes down to the fact that there is no competition between any of the industries within the symbiosis, and the economic sense of trading energy, water and waste materials. Without the competition, businesses can work together in maximising each others profits – doing so is for their own benefit. Trading different streams also creates new revenue for each company whilst also reducing costs of sourcing energy, water and materials externally.

Kalundborg, Denmark (Source:

The benefits that this has on the environment are huge. The locality of the businesses working together reduces the need for transport over long journeys that are common with the current economic model. Energy that would usually go to waste can be reused and the amount of water required by each company is reduced, easing pressures on surface and groundwater sources. The recognition that one company’s waste is another’s resource dramatically reduces the amount that would go to landfill or be incinerated.

There’s no reason a similar symbiotic relationship couldn’t be built between company’s in industrial areas all over the world, even those already existing. We need to be smarter when planning where to be based and start asking questions about how a company can benefit those around it whilst also receiving benefits themselves. The reduction in emissions possible in an industry that is typically resource-intensive would go a huge way in ensuring we keep global temperatures below the 1.5℃ needed to avoid the worst impacts of climate change. In water-stressed areas, reusing waste water between companies can reduce the need for water from dwindling sources and ensure sustainability over the long term.

And not just for the environment either, it makes economic sense to do it this way as well. The bottom-line savings speak for themselves and are something that every company is always looking to reduce. Surely, more companies should be looking at the Kalundborg Symbiosis blueprint and planning for a more sustainable future?

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