Opinion

The Energy-Water Nexus: Finding Solutions in the Balance

07/25/2010

Water, energy and climate change

All sectors of the global economy face challenges today from growing populations, and increasingly, climate change. Companies and public utilities face growing pressures from regulators, shareholders, surety providers, non-governmental organizations, and the public on how energy, and thus carbon emission, are being managed. Simultaneously, water availability and quality are issues that affect businesses and public utilities. Water risks are real now and are widespread. And the future only looks worse due to two main factors:

  • Population growth will decrease fresh water per capita availability
  • Climate change is projected to increase water variability due to droughts and floods, a problem for many of the world’s power and water treatment plants – which have been designed on the basis of steady state conditions.

Steady state is out of date and adaptation to projected climate impacts will be very much about water. Climate change has been and is projected to further impact water availability, quality, and predictability of flows in a number of ways:

  • Increased temperatures would increase evaporation rates and decrease water availability.
  • Decreased precipitation is predicted for the low and mid latitudes.
  • Increased droughts and floods would increase variability.
  • More frequent storm events would also increase variability.
  • Rising sea levels would increase salinity and impact fresh water quality.
  • Shrinking snow cover would have a major effect on water storage in the western US since snow pack is a wonderful, low cost natural storage mechanism.
  • Rain instead of snow will not be caught and saved unless new storage capacity is created.
  • And ocean acidification would impact ecosystems.

The trends are not our friends on water issues, and to make matters worse, we will have a significant need for more water to provide energy for the nine billion people who will be on the planet in 2050, creating the global sustainable energy and water dilemma: decreasing water availability and increasing demand for energy, resulting in local energy water tensions and tradeoffs. Thus, while there are uncertainties associated with climate change projections and the evolving regulations, companies and public utilities must now deal with a convergence of energy, water and carbon issues that are impacting their operations and planned projects. These impacts are found in all sectors and across all geographical regions.

Water in Energy

"Energy production is now constrained by water availability."

Energy production is now constrained by water availability and this linkage must be included in energy planning. In the Power Industry, large amounts of water are required for cooling, steam generation, and flue gas treatment. The major consumptive use of water in thermal production of electric power is from evaporation in cooling towers. When carbon capture and storage (CCS) is added to power plants to reduce carbon emissions (and hopefully to reduce the rate of climate change), the water intensity of power production increases even more. Droughts and increasing temperature could have major impacts on power plants as permitted discharge temperatures could be exceeded. There are also areas of high water use in the Petroleum Industry’s value chain as well as in the Biofuels Industry.

The Energy Industry understands that predictable, affordable and clean water supplies are core to their businesses and many companies and public power providers are taking action to minimize risks by seeking innovations and implementing sustainable water practices.

Energy in Water

From the Water Industry’s perspective, there are critical linkages between energy use and providing adequate, consistent water supplies to customers. Moving, treating, and controlling water are energy-intensive activities, potentially putting them at odds with Greenhouse Gas (GHG) reduction goals. Over the past decade, the economics of energy use have changed rapidly, requiring a rethink of how water infrastructure uses energy and how to improve energy efficiencies and reduce GHG emissions.

"Doing more with less."

The Water Industry is becoming more focused on the water-energy-climate nexus as it knows that water, energy, and greenhouse gases are closely related—requiring a balance as the basis for sustainable communities. The water-energy-climate nexus is critical because its effects are widespread— it affects social, environmental, and economic interrelationships.

Increased energy costs and concern over GHG emissions have spurred a number of utilities and governments to take action. While the Energy Industry is working on conserving water, the Water Industry is working on energy management. These industries are essentially following the same processes -- doing more with less. Water utilities are applying energy management to all aspects of business that consume energy including new construction, facility renovations, purchasing activities, operations, and maintenance. Certain approaches to power water treatment and movement, such as the use of renewable energy (e.g., through solar energy, digester gas, or the use of combined heat and power distributed generation) have the potential to greatly reduce the environmental impact and greenhouse gas emissions associated with plant operations.

CH2M HILL has been helping companies and public utilities to generate and to conserve water and energy for over 60 years. More recently, reducing GHG emissions has been added to the equation. In working on these complex issues around the world, we’ve learned that it takes balance to find the optimum solution.

Keywords:

Water, Energy, Climate Change, Greenhouse Gas

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The views expressed in this article are those of the author(s) and do not reflect the official policy or position of Johns Hopkins University or the Johns Hopkins University Global Water Program.