ABSTRACT
In 1989, the international community learned that a cluster of factories in Kalundborg, Denmark were arranged in a network unlike anything the world had ever seen (Chertow, 2007). Instead of adhering to the traditional form of production and waste discharge, these factories were arranged in such a way that the wastes from one factory were used as inputs for another, and infrastructure such as steam generation was shared between multiple firms. Cooling water from an oil refinery was used as input water for a desulfurization process, which in turn produced industrial gypsum, which replaced use of natural gypsum at a co-located plasterboard factory (Jacobson, 2008). Each factory was linked in a complex network of energy, solid waste, and material flows.
