Want to Save Water? Use Less Energy

When weighing the benefits of energy savings with a project’s budget, owners usually don’t look past reaching code standards and certification levels or the money saved from avoided energy consumption. However, reducing energy demand also reduces our consumption of another important resource- water.

Water is required to generate electricity from fossil fuels. Coal fired power plants are the largest water consumer because the process requires water to extract, clean and sometimes transport coal to the power plant, where more water is then required to cool steam and control pollution at the site. The International Energy Agency estimates 580 billion cubic meters of freshwater are withdrawn for energy production each year, making it the second largest source of water withdrawal in the world.

At the state and national level, water consumption from energy production can be dramatically reduced by switching to energy sources that use significantly less water, such as natural gas. Solar and wind are even better alternatives because they require no water for electricity production. This does not include the water used to manufacture renewables, but the amount of water used to produce the panels and turbines is negligible compared to water consumed to operate coal fired power plants.

Building designers, who rarely have a direct impact on U.S. energy policies, can do their part by aggressively driving down energy demands and encouraging owners to use on site renewable energy generation to offset electricity consumption from the grid. Investments in reducing grid electricity consumption become more enticing in states like California where freshwater supplies are severely threatened.

Some would argue that if projects could recognize water and energy savings outside the project’s site boundaries, engineers would make decisions using a full life cycle analysis (LCA). However, if design teams were allowed to recognize water savings from reducing energy consumption, should they then be forced to benchmark their efforts as a percentage of the total water use at the power plant attributable to energy generated for the building?  The absolute amount of water savings seems significant, yet when compared to the total water demand the savings become less impressive.

The flip side of this argument is that increased transparency might lead to designers making better decisions that benefit more than just those who own and occupy the building. Rating systems like LEED are experimenting with offering points for whole-building LCAs that show significant reductions in CO2 and other substances that have negative environmental impacts.

Ultimately building codes and rating systems will need to include a scoring methodology that allows buildings to recognize savings beyond their project’s borders without being misleading about the building’s total footprint. As stakeholders continue to demand more transparency, we expect to see LCAs playing a bigger role during the building design process.

 

Photo from http://www.gettyimages.com/detail/video/coal-river-morning-hd-stock-footage/463254456

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