Water and Energy - Inextricably Linked

As we observe World Water Day (WWD) on March 22, 2010, it is useful to reflect on the connection between water and energy.

First, some background on World Water Day: It is a United Nations event that began in 1992 after the Earth Summit in Rio de Janeiro. Each year the U.N. highlights one or more issues relating to freshwater supplies and quality. This year the U.N. chose Clean Water for a Healthy World as its theme. The overall goal of the World Water Day is to raise the profile of water quality at the political level so it is considered alongside decisions regarding water supply.

While the technology sector is very focused on energy, the nexus between energy generation, use and water is not generally recognized. Here are some relevant facts:

• Electricity production requires about 136,000 million gallons of freshwater per day, accounting for over 40% of all daily freshwater withdrawals in the United States.
• Texas power plants use over 157,000 million gallons (482,100 acre-feet) of water annually - enough for over 3 million people for a year, each using 140 gallons per person per day.
• In many regions of the U.S., we indirectly use as much water turning on the lights and running electric appliances each day in our homes as we use directly in taking showers and watering lawns.
• The energy required to move water from its source across varying geographies, to then treat the water and finally to convey it to users is also enormous. The single biggest energy use in California is the water projects (State and Federal) that consume nearly 12% of the State’s electric energy.
• In North America, approximately 90% of wastewater is treated; in Europe the figure is 67%; in China, a little less than 40% is treated before discharge. In developing countries, however, 80% of all waste is discharged untreated, because of lack of regulations and resources. And population and industrial growth add new sources of pollution and increased demand for clean water to the equation.

The environmental footprint of many products is being evaluated today in terms of "embedded carbon", meaning the amount of greenhouse gases associated with the production of the good or service; in most instances a significant amount of the embedded carbon is due to electricity required to make the product. "Embedded water" or the amount of water required to make a product is also being examined and the results can be eye-opening, e.g. a kilo of eggs has 3,300 liters of embedded water, a pair of jeans 10,850 liters and an automobile 400,000 liters.

Water is already an extraordinarily stressed natural resource, as those of us in California know all too well. While carbon dioxide (CO2) has in some ways become the surrogate metric for overall environmental impact, it is important to consider other dimensions as well, not only in terms of business decisions, but also in terms of lifestyle changes. So, when you turn your light on to read your favorite book, pause for a moment to think about all the resources used to make that little lamp burn so bright.

Image courtesy of the U.N.