The circular economy and the water-energy-food nexus

Since the industrial revolution the total amount of waste generated has constantly grown as economic growth has been based on a ‘take-make-consume and dispose’ model. This linear model assumes that resources are abundant, available and cheap to dispose of. In Europe there is a move towards a circular economy where existing materials and products are reused, repaired, refurbished and recycled.

Circular economy


At the aggregate European Union-wide level, resource productivity in the EU grew by 20% between 2000 and 2011. While some of the increase in efficiency was due to the effects of the recession, if this rate was maintained it would lead to a further 30% increase in efficiency by 2030 and boost GDP by nearly 1%, resulting in an additional 2 million jobs. In addition, if European companies implement waste prevention, eco-design, reuse and other similar measures it could bring net savings of EUR 600 billion while reducing annual greenhouse gas emissions by 2-4%. Meanwhile, the global market for eco-innovation is worth currently around €1 trillion per annum and is expected to triple by 2030. As such, eco-innovation represents a major opportunity to boost competitiveness and create jobs in European economies.


In the Asia-Pacific region, three out of four countries already experience water scarcity. With climate change further impacting the availability of water, which affects the production of energy and food resources, as well as rapid population and economic growth increasing demand for energy and food, the transition towards the circular economy in Asia-Pacific is critical in ensuring economic and political stability.


With Europe being a leader in circular economy advancements there are many examples of technologies that can be exported to the Asia-Pacific region to boost competitiveness and create jobs in European economies while reducing the potential for instability and conflict from water-energy-food nexus pressures.


The water-energy nexus


Water and energy are linked in two ways: first, water is used in the production of almost every type of energy (coal, geothermal, hydro, oil and gas, nuclear) and second, energy is a dominant cost factor in providing water and wastewater services. In Asia, increasing access to energy is a priority as around 700 million people lack access to electricity and 1.9 billion rely on biomass (e.g. wood) for heating and cooking. Despite creating alternative energy sources, over 80% of the expected increase in energy use to 2035 will come from fossil fuels, particularly coal which in addition to being water-intensive will lead to global warming, further exacerbating water scarcity. One of the most challenging aspects of the water-energy nexus is that low-carbon growth targets for energy generation place stress on water availability. Among the renewable energy sources available hydropower is likely to become the dominant source of low-carbon energy in the future. However, not only does hydropower consume water through evaporation from open surfaces of reservoirs but it also impacts availability of water for downstream users (agricultural, fishery, industrial, municipal etc.).


In Amsterdam, the city’s main wastewater treatment plant ‘Amsterdam West’ operated by Waternet is located beside a waste-to-energy plant operated by AEB Waste to Energy Company. The close proximity enables an exchange of energy flows between the two plants with large environmental benefits: Amsterdam West produces 25,000 m3/day of biogas and 100,000 tonnes of sewage sludge per year for burning at the waste-to-energy plant. The energy produced in the waste-to-energy plant is then used to power the Amsterdam West treatment plant.  In total, the integration of the two plants produces 20,000MWh/year of electricity and 50,000 GJ/year of heat saving 1.8million m3/year of natural gas, resulting in avoided greenhouse gas emission of 3,200 tonnes per year.


The important take-outs from this example of reducing water-energy nexus pressures in Amsterdam is that industrial processes can be connected to prevent industrial by-products from becoming waste, which in turn reduces the quantity of water and energy required in treating wastewater, reducing water-energy pressures. This technology can be exported to the Asia-Pacific region by providing technological and engineering assistance with the aim mainstreaming in cities waste reduction and high-quality separation of waste for secondary use in Asia-Pacific.


The water-food nexus


Water for food production accounts for around 70% of water withdrawals, however, with increases in population growth, urbanization and economic growth along with changes in diet as prosperity increases, demand for food will increase significantly. For instance, a change in lifestyle and diets in Asia will increase demand for water-intensive products such as meat and dairy products. Globally, demand for phosphate as a fertilizer nutrient will rise from 43.8 million tonnes per annum in 2015 to 52.9 million tonnes in 2030.


Currently, Asia currently accounts for almost 60% of the world’s total nutrient use, with China and India consuming around 55% and 29% of Asia’s total consumption of fertilizer. Over the next five years, Asia’s consumption of fertilizer will increase by around 6% due to changing and interconnected trends including economic and population growth and increased demand for food.


In the United Kingdom, Thames Water in partnership with Ostra Nutrient Recovery Technologies has launched the UK’s first nutrient recover facility at Slough Sewage Treatment Works producing commercial fertilizer from wastewater. Phosphorous and nitrogen concentrated in the facility’s wastewater can form a concrete-like substance called struvite which coats pipes and valves, reducing the plants efficiency in treating wastewater – an energy-intensive process resulting in costly maintenance. The plant’s nutrient recovery system addresses these issues by converting the struvite into pellets of high-grade fertilizer. The plant will produce 150 tonnes of fertilizer pellets a year for sale to crop-growers as well as gardeners. Economically, the plant will also save £200,000 per annum by avoiding operation and maintenance costs.


The important take-outs that can be exported to the Asia-Pacific region from the example in the UK of producing fertilizer from sewage is that circular economy technologies increase efficiency in operations and reduce maintenance costs, increase security of supply of scarce resources, in this case fertilizer for food production, while reducing energy requirements (and water use). However it is important to create a viable market for secondary raw material to close the loop – turning waste into a resource, in this case selling recycled phosphorous as fertilizer pellets.


In the Asia-Pacific climate change is impacting the availability of water, which in turn creates water-energy-food nexus pressures. In addition, rapid population and economic growth is increasing demand for scarce resources, leading to potential economic and social instability. With technological advances in Europe in the areas of waste-to-energy and phosphorous recovery from wastewater there is the potential of job creation and growth in exports in technologies that reduce pressures over scarce resources in the Asia-Pacific region.


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Author: Robert C. Brears

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  1. Dear Robert,
    Thank you for your really excellent article!
    I introduced the climate footprint measurements at waternet back in 2007. Last year, I spent a lot of time looking at opportunities to close nutrient loops with and within India.
    I’d be interested to see if we can somehow work together. Do let me know.
    Peter Wiers
    Climate Partners/ PW Advies

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  2. Thanks for this information. Please, What effects can the nexus have on Water Quality as regards the Water to energy (Hydro power) and Water to Food? How do you think these nexus challenges on water quality can be resolved? Thanks in anticipation for your response.

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  3. Dear Robert,

    Thank you very much for your article which I read with great interest. There are indeed major opportunities in efficiency enhancement taking place. However, still many of them are end-of-pipe solutions. A full circle value chain analysis will allow for redesigning industrial processes, encompassing waste reduction, water usage and energy reduction, protection methods of products, including packaging etc. Some years ago I contributed to a study on the packaging industry which takes recycling very seriously, but we found that avoiding/reducing food-waste in the first place would be much easier and have a much greater impact. Reducing food wast from current 50% to 40% for the whole of the EU (i.e. minus ten percentage points only) would equate to one-sixth of total CO2 emissions of the Netherlands that can be avoided, i.e. more impact than efficient packaging recycling only. Let alone the reduction of water usage. Awareness is where impact initiatives will start. Your contribution using best practices is a great contribution.

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