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The Connection Between Water & Energy
Deep dive into the interrelationship between water, energy, and food, sharing a view of the world in its complexity and how one resource impacts the other
What is the connection between water, energy and climate action?
Over the past decade there have been many attempts to accurately forecast the impacts of population growth on the demand for food, water and energy in 2030 and beyond. Such modelling has proven to be much more difficult than envisaged with almost all revisions highlighting even greater demands on resources over time. This is particularly the case for water. The rate of growth of water-related risks is far outpacing the efforts being made to mitigate those risks. In 2015 for example, the World Resources Institute projected a 40% gap between fresh water supply and demand by 2030; it has since revised that number to 56%. This ever-widening disparity is attracting the attention of investors, shareholders and regulators.It is not simply that more people require more water but rather how the rapidly expanding global middle class is demanding much more water. During the 20th century, while population grew by a factor of four, freshwater withdrawals grew by a factor of nine. If we extrapolate this to 2030 the outlook is stark. To make predictions even more complicated, urbanization is happening at an accelerated pace—the volume of urban construction over the next 40 years could equal that which has occurred throughout history to date creating huge resource ‘hotspots’ which quickly outstrip local water availability.
Superimposed on all this complexity is the interconnectivity between resource types. In the past, water, food and energy were typically dealt with as separate issues. Biofuels are a classic example of this. Once hailed as a breakthrough for sustainable energy, bio-diesel's insatiable appetite for wheat caused spikes in food prices and even led to civil unrest. Global water demand would have also increased by 6-7% for only a 10% conversion of fossil fuel to biofuel used for transport. This serves to illustrate how vital it is that solutions equally consider the other components of the so-called ‘nexus’ for water, energy and food.
The nexus approach
Adopting a nexus approach especially highlights the importance of the water-energy component. While global domestic and industrial use of freshwater only account for 8% and 22% respectively, compared to 70% for agriculture, the considerable amounts of energy associated with abstracting, pumping, treating, heating, cooling and cleaning water greatly magnify the impact of industrial water use. This is especially the case in Europe where the industrial use of freshwater is more than twice the global average. Electricity consumption for pumping systems alone can represent 25% of electricity use for many industrial sites. We see increasingly that operations cannot adequately decarbonize without understanding the essential role of water, particularly as an energy transfer medium. In oil refining, for example, between 35 and 47% of the site’s total energy is transferred in steam production and cooling water.On the flip side, energy production requires significant inputs of freshwater. In Western Europe, over a third of all abstracted water is used for this purpose. In a conventional thermal power plant, 85 – 95% of the total water needs is for cooling, equating to around 60 billion m3 of water abstracted in Europe per annum. Remarkably, more of the intrinsic energy associated with the fuel consumed by such plants is rejected to the cooling system (and consequently the surrounding atmosphere) than is actually converted into electricity.
How water and energy are interlinked
The interdependency of water and energy is set to intensify in the coming years, with significant implications for both energy and water security. Currently, water scarcity is somewhat compensated through high-energy reserves and economic power. By 2040, desalination projects will account for 20% of water-related electricity demand. Large-scale water transfer projects and increasing demand for wastewater treatment (or improved treatment processes) also contribute to the water sector’s rising energy needs and raise concerns on the potential for fugitive emissions of methane - a powerful greenhouses gas with a 100-year global warming potential ~30 times that of CO2. These all have significant implications for emissions and growth. Consequently, it is vital we better understand the interrelationships between water and climate, not least as water is the primary medium through which we will feel the effects of climate change. Therefore, at the heart of water-energy nexus is the rapidly growing appreciation that climate and water systems are linked, and changes in one system induce important, non-linear changes in the other. Water supply and demand and energy production have an impact on climate; climate changes affect the availability of water; and the availability of water, in turn, has an effect on energy production.
Water: a local issue
Unlike energy supply with its global political and economic dimensions, the availability of water is very much a local issue which will have to be addressed by improved governance at the catchment level. Similarly, the pathway to a low carbon economy could easily exacerbate water stress or be limited by it if it is not properly managed. While technologies such as wind and solar PV require very little water, others like biofuels production, concentrating solar power, carbon capture and storage (CCS) and nuclear power typically have more significant water demands.While most organizations have set clear climate and water goals as part of their 2030 ambition, it is increasingly evident that a large percentage do not have a sufficient plan in place to achieve them. Given the water-energy nexus, an organizations’ water and climate strategies need alignment to achieve their full potential.
Ecolab serves some of the most water and energy intensive industries across the globe. These industries include power generation, data centres, paper, automotive, beverage brewing, and steel/primary metals. Ecolab’s unique mix of technologies, insights and expertise reduce water and energy demand, and ease potential chokepoints in the water-energy nexus. Given the complexity of water as a local, finite and shared resources, Ecolab recognises the importance of adopting a water stewardship approach to drive smart water management for business and industry, to support climate resiliency and help protect communities.
Case studies: examples of the linkages between water efficiency and energy savings
The case studies set out below provides examples of the linkages between water efficiency and energy savings. In many cases the payback period is just a few months and can often be financed through normal operating costs and without large upfront capital expenditure.3D TRASAR® Technology for Cooling Water Improves Environmental Performance and Increases Operating Profitability by over € 1.2 million per year at a Combined Cycle Gas Turbine (CCGT) power plant in Southern Europe.
A 400 MW combined cycle gas turbine power plant in southern Europe uses seawater for cooling the condenser. The seawater intake channel is close to a waste-water discharge point for a large industrial complex and this (plus tidal effects) produce a high variability in the quality of the water received. In turn, this impacts the cleanliness of the condenser and hence the energy transfer efficiency. An advanced monitoring and control system that is able to track changes in water quality and automatically adjust the concentrations of scale inhibitors and dispersants accordingly was installed in the cooling water circuit. This predictive capability allows for intervention before problems occur. This cooling system management approach resulted in:
= 2.46 million kgoe per annum
= 28.6 million kWh per annum
