I recently came across a blog by Abheek Chatterjee  , a researcher at the National Institute of Standards and Technology (NIST), that resonated with my belief that you should consider environmental impacts in any new design. He writes about “the importance of using sustainability analyses early on in an engineering project so we can better understand the bigger-picture environmental impact of seemingly small decisions, such as choosing materials for a product.”

Chatterjee works on ways to help companies figure out how to benefit both themselves and the environment by sharing resources. “What if one company’s trash could be another company’s treasure?

“There is very little waste in nature. For example, certain bacteria and fungi decompose dead organic matter, reintroducing nutrients back into the soil for plants to use as they grow,” said Chatterjee.

Dubbed Industrial Symbiosis, this is not a new idea — it has been developing organically at the Kalundborg Eco-Industrial Park  in Denmark since 1972. In fact, the term was first coined by a manager at Kalundborg. Its success illustrates that the practice works best when companies are located near each other. Over time, companies at the park realized that they could help each other.

In Kalundborg, the city’s large industrial companies work together across sectors to share excess energy, water, and materials, so less goes to waste. Public and private companies are physically connected, so one company’s surplus of resources adds value to another. Today, more than 30 different streams of excess resources flow between the companies.

The 1500 MW Asnaes coal-fired power plant at Kalundborg is central to the arrangement. It provides surplus heat for 3,500 local homes and a fish farm whose waste sludge is sold as fertilizer. Steam from the plant is sold to the pharmaceutical company Novo Nordisk and to the Statoil oil refinery. Gypsum, a byproduct of the power plant’s sulfur dioxide scrubber is sold to a wallboard company and other power plant byproducts are used for road fill and cement manufacturing.

According to the Kalundborg website  , they save 4 million m³ of groundwater by using surface water instead. 62,000 metric tons of residual materials are recycled, and enough CO₂ emissions are reduced so that the local energy supply is CO₂-neutral.

In another part of the world, an Integrated Biosystem project in the Fiji Islands uses spent grain from breweries to grow mushrooms, which break down the waste, making it into a high-value pig feed. The waste generated by the pigs is treated through an anaerobic digester, and then piped into fishponds, making the water rich in nutrients by generating food for fish.

Cooperation to Help Solve Western U.S. Water Problems

A new study  led by researchers at the University of North Carolina at Chapel Hill offers a solution to water scarcity due to economic development, population growth, and climate uncertainty. Two-way leasing contracts would coordinate agricultural-to-urban leasing during periods of drought and urban-to-agricultural leasing during wet periods, benefiting both urban and agricultural water users.

The study tested a two-way option contract for water users that can quickly respond to wet or dry conditions. These contracts are signed in advance of a drought and can provide both cost savings and high water supply reliability for cities, which can use them to quickly acquire water from irrigators during dry periods. This arrangement allows cities to forego developing large and expensive supplies that are rarely used. Agricultural users receive annual option payments from urban users, and higher fees in dry years when the water is transferred. In normal and wet years, these two-way option contracts result in excess urban supplies being transferred to irrigators who then benefit from higher levels of agricultural productivity in these years.

Lessons Learned

The Kalunborg Symbiosis website makes the important point that “the Symbiosis model also creates another surplus — the trust and power of innovation within the community. It benefits the people such as employees, students, researchers, as well as the climate. Sustainability and profit go hand in hand — something we want to be the next normal.”

It takes a lot to get projects like this underway. As Chatterjee said, “Sustainability and resilience are complex and multifaceted, and so is researching these topics. It’s not just science but also math, economics, and even a bit of sociology. Sustainability research gives me the opportunity to use my curiosity for mathematics and apply it to address complex, real-world challenges.”

Chatterjee is doing the very important work of developing “metrics and evaluation methods” to help potential adopters of Industrial Symbiosis determine whether it will be worth their time and financial investment.

This is a theme that I also encountered when I was writing an earlier blog about integrating sensing and control to optimize energy systems. Jibonananda (Jibo) Sanyal and his team at the National Renewable Energy Laboratory (NREL) are building a tool that allows an energy auditor to think through and quantify the benefits of considering environmental effects. “Because if you can quantify, it helps with your ROI,” said Jibo. “The tool is designed to be used by all levels of stakeholders from the plant managers to the C-suite executives who make the final financial decisions.”

There are clearly many benefits from adopting Industrial Symbiosis, but there are huge issues. Not only are the challenges technical and economic, but encouraging a mindset that will convince CEOs, government officials, and consumers that it’s worthwhile is equally challenging. Experience has also shown that a vital element for success is that the partners trust each other. These “soft” factors are just as important as the technology.