Delta Life 8

25 ENERGIE T he main challenge for the circular economy is to stop thinking in terms of separate sectors such as water, energy or agriculture. For instance: farmers these days cultivate energy crops such as rape seed, sugar beet and algae for biofuels that reduce carbon emissions. But growing these crops requires water and nutrients that are also scarce. 1 Twente University recently estimated that the production of 1 litre of bio­ ethanol costs an average of 150 litres of water. Biodiesel requires four times that amount. So something that is, in itself, a positive development can have a negative effect in the longer term or on a larger scale. Deltares advises focusing not just on one cycle, but precisely on the inter­ action between different cycles. This nexus approach leads to innovative research that can make a significant contribution to a society in which the economy can operate without endangering the availability of resources that are already in short supply. Dam Another example from Deltares practice: an energy company manages a dam. 2 Deltares was asked to map out the upstream and downstream impact. Researchers are now engaged in a model study looking at the management of the reservoir. Normally, the central focus would be on maximising energy production by looking at the practices of the energy company. The economic interests of other sectors such as farming and fishing, which also depend on the river or the reservoir, are not always given equal consideration. From an economic point of view, that would seem to make sense: an energy company benefits from reservoir management with the highest yield. But looking at the longer term for the entire river basin and all the sectors concerned leads to different conclusions. If we want to build a circular economy, it is better to look at how we can also give other interests the consideration they deserve. Quantifying the balance between the interests of the different sectors allows both public and private bodies to make decisions using hard figures. Take the costs and benefits of different climate scenarios, for example. 2 Researchers map upstream and downstream effects for an energy company's dam. The circular philosophy means that you also involve the interests of other sectors that depend on the dam as well, such as farmers and fishermen.