25 Jul 2012

Watergy Nexus: Our interconnected consumption

Editor's note: James Workman taught "Unlocking the Real Worth of Water" as a visiting professor at Wesleyan University last semester. He told his students that they -- like all people -- needed to be "water resource managers" because water allocations are increasingly driven by subjective individual values, not top-down planing. The students addressed these ideas from different perspectives (local utility, energy/water nexus, and water and food trade); each choose one essay to post here. Please tell them what they got right or wrong.

Delphine Starr writes...

Feel guilty for that twenty-minute shower on a cold winter morning? Worry not. You’ve been turning off your lights, installed energy-saving light bulbs, and you’re biking more to reduce gasoline consumption. Your carbon footprint has shrunk and you (and your wallet) feel good about it. So why not treat yourself to that nice long shower? The water bill’s so cheap and you’d rather be saving money on pricier commodities such as gas, electricity and food. Anyway, saving the world means reducing carbon emissions, right?

You’re headed in the right direction, but only about halfway there. What you (and I both) have neglected is that water is energy.

"What?" you think, "Water isn’t energy; water is water." Well, let’s look at your shower. How exactly did the water get to your pipes? It takes 440 BTU (British thermal units) to heat one gallon of water. Since a shower uses up to 5 gallons of water per minute, that’s about 2200 BTU per minute. According to these numbers, roughly 44,000 BTU was needed in order for that water to be extracted from an aquifer, purified, distributed, and transported to your showerhead. That’s about 13 kWh. It seems simple when all you have to do is turn on the faucet for hot water to magically appear. Yet the energy embedded in that shower of yours is enough to power a light bulb for a full 130 hours or run your refrigerator for 2.6 days straight. How are you feeling about your carbon footprint now?

In short, the water-energy nexus reveals the direct correlation between water and energy use. This symbiotic relationship means that decreasing water consumption will lead to less energy use and vice versa. In New York state, for example, the average cost for electricity is 18.1 cents per kilowatt-hour. This number doesn’t seem too steep until considered alongside the whopping 95 liters of water that it takes to produce one mere kWh of electricity. So if all of us in the state decrease the amount of water we consume, we’ll also begin to see significant savings in our energy bills and a reduction in carbon.

While these statistics may seem obscure when viewed on their own, think about what your 20-minute shower means for our collective energy and water consumption when combined with that of 300 million other Americans. Each year, the U.S. uses 520 billion kilowatt-hours to move, treat, and heat water. That’s approximately 13% of the nation’s total electricity use!

As a global society, we have subconsciously compartmentalized commodities to exist as singular entities. As a result, water, energy, and even food are seen as polarized when they are in fact very intertwined. Instead, it is important to view them comprehensively and to recognize that a shortage of any of these resources causes a ripple effect on the others. By acknowledging that energy is embedded in water and that water is embedded in carbon, we can recognize that food, water, and oil are resource challenges that should not be seen as individual issues but rather as interlinked.

Over the next ten years, the world population is projected to rise to approximately 7.7 billion. The International Food Policy Research Institute estimates a 30% increase in domestic and industrial demand for water. Meanwhile the International Energy Agency forecasts that the world economy will demand at least 40% more energy between now and 2030. Keeping in mind the energy-nexus, the production of this energy will have a direct effect on freshwater resources and vice versa.

It can be easy to go negative and get depressed when discussing these statistics and our society’s over-consumption of dwindling resources. However, in recognizing the water-energy nexus, we are presented with an extraordinary opportunity to reevaluate and transform the ways in which we currently approach these issues.

Luckily, water and energy conservation opportunities are readily available. By seizing water efficiency opportunities such as better farming techniques, water supply systems, or improved factory infrastructure, we can simultaneously reduce energy consumption. The energy-water nexus is empowering in that it means that conservation, in either sector, is a win-win. By conserving water, or energy, there are no tradeoffs that need to be made between limiting carbon emissions. Once we begin to look at these resources holistically, we can alter our current mentality and begin to track our water and carbon footprints in lockstep together.