There has been no drought of studies, articles and blog posts about the connection between water and energy in the past 2-3 years (e.g., see recent Special Report on Water vs. Energy by IEEE Spectrum), but I would like to add a few thoughts to what is still an emerging area. It is perhaps fitting that I am posting this from the Washington Dulles airport, in town for a water policy conference, since it was from right here in the airport last December that I launched the PrivateWaterLaw Blog.
The basic observation is that water and energy supplies are connected, both directly and indirectly, in many ways. As affluence increases across the globe, demands for both water and energy are rising significantly, and the connection between the two causes a feedback loop that drives demands for each even higher. Shortage of one resource can limit the other, and thus retard economic growth. Despite the current economic troubles, I believe that most world citizens expect (and hope) that global affluence will continue rising, especially in developing nations and regions.
Effects of increasing water supplies on energy include:
- Desalination and water recycling plants require large quantities of energy for filtration or distillation processes;
- Conveyance of water (which is very heavy) from areas of abundant supply to areas of demand requires significant energy for pumping;
- Treatment for use of natural or human-caused water supplies of poor quality requires energy; and
- Water conservation frequently requires increased energy, such as smart grids and replacing open gravity irrigation canals with pressurized pipelines.
Likewise, energy production has many effects on water, including:
- Significant use of water for cooling in conventional, nuclear, thermal solar and geothermal energy generation;
- Use of water in extraction of energy sources, such as in oil and natural gas production and coal mining; and
- Irrigation of crops for use as biofuels.
Some observers believe (or, perversely, want) the water-energy connection to be a vicious cycle, that cannot be easily solved and is destined to constrain the world’s economic and population growth. This is especially true when combined with the projected effects of climate change. While it certainly has a braking effect on growth, I do not believe the cycle needs to be vicious in the long term.
There are several ways to avoid the vicious nature of the cycle. On the water side, managers, companies and individuals should consider the energy requirements of their alternative water demands and supplies when planning for the future, and vice versa. Water and energy need to be included in the same calculus. New projects should be evaluated for the ability to provide more value to the water-energy joint calculus than their costs. In addition, when feasible from technical, economic and environmental perspectives, priority should be given to alternatives that break the cycle entirely, such as photovoltaic energy generation that does not require cooling water, or use of otherwise unusable seawater for cooling nuclear-powered desalination. The cycle can be broken on a global basis, or locally, through the importation of energy into areas with low water supplies, thus applying the concept of “virtual” water transfers.
One last observation is key: economic subsidies of either water or energy produce distorting effects not just for that resource but also for the other. Consider the case of India, where subsidized energy for irrigation has led to depletion of groundwater supplies and perhaps, with a cruel irony, food shortages. As we develop solutions, there will undoubtedly be subsidies and distorting effects that are temporarily necessary, and it is right to accept reasonable distortions, but long-term we must seek to minimize subsidies in both the water and energy sectors. Reduction in such subsidies and the resulting increase in water and energy prices may have a dampening effect on growth in global affluence, but in the end will produce a better, more sustainable future.