Assorted Links

San Francisco parks waste thousands of gallons of drinkable water each day through cracked pipes and aged irrigation systems.

California’s Green Building Standards Code – known as CalGreen – will become mandatory on January 1, 2011.

A new study reports that most heat pumps in the UK are not performing as intended.

A competition focusing on the Water-Energy Nexus is looking for start-ups that save energy in moving, treating and using water and wastewater.

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The Energy-Water Nexus


This post is part of our definitions series on “eco-lingo” and technical terms.

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We have been hearing with increasing frequency about “the energy-water nexus” in California as we face potential changes to our climate and our water supply. But what is it?

Basically, water and energy supplies are fundamentally linked together. Producing energy requires a huge volume of water (even for renewables). Treating and distributing water requires a consistent supply of energy. Therefore, serious challenges to the supply of one threatens the reliability of the other.

According to Sandia National Laboratory, producing electricity from just fossil fuels and nuclear energy requires 190 billion gallons of water each day, which accounts for 39% of all U.S. freshwater use. Each kWh generated from coal necessitates 25 gallons of water (source here). Also, since the energy needed to treat and distribute water can account for up to 80% of the water’s final cost, a reduction in the amount of available, inexpensive energy will have a direct impact on the cost and supply of water.

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What exactly does “sustainability” mean? How about “green”, “eco” or “environmentally friendly”? The truth is that these terms are just vague enough to mean many different things to many different people. With the staggering array of “green” products, ‘lifestyles’ and concepts being promoted by marketers and environmentalists alike (as well as the necessary coining of new terms to match new ideas) our definition series aims to make sense of the rising tide of “eco-lingo” and technical terms.