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 The International Energy Agency estimates 580 billion cubic meters of freshwater are withdrawn for energy production each year, making it the second largest source of water withdrawal in the world.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

Affordable, Clean Energy Solutions on Display

Each year, the Department of Energy hosts their annual Solar Decathlon, a competition which challenges bright young engineers to design, build and operate the most attractive and efficient clean energy powered houses.  This annual event has fathered many practical ideas that can live in the ‘real world’ where a lot of untried theories fall flat.

Interdisciplinary collegiate teams strive to earn points for design, marketability, affordability, engineering and energy efficiency, and their ability to communicate their design vision with a clear and consistent message. The competition has rules, of course, that allow the jury to compare apples to apples.  The house size, conveniences, appliances and power requirements for modern living are all detailed and built according to code.  Maxing out at 1,000 square feet, some entries have gone on to become second homes or vacation cottages for private owners.

2013’s winner was Team Austria who nosed out the University of Las Vegas by a mere 4.35 points (out of a maximum 1,000 possible).  Their LISI Home shows that we’re way beyond hippie rustic with its sleek, elegant Scandinavian inspired design.  And, like some of its predecessors, you can buy one for yourself.

One of the more provocative entries was 2005’s Solar Hydrogen Home. Christened “The Green Machine-Blue Space” by its designers at the New York Institute of Technology, this creative design featured complex engineering that used solar power to crack water into its separate gas components.  They captured the hydrogen, stored it in a special vessel with redundant safety features, and used hydrogen to power the home!  Admittedly, this was a little weak on the “affordability” category, and requires careful safety measures.  We haven’t seen much tweaking on it – yet.  But it does provoke thinking outside the box.   And it’s hard to imagine a rural farm that would not benefit from this technology.  This home now stands) on the grounds of the U.S. Merchant Marine Academy.

The competition has expanded to Europe, China, Latin America and the Middle East. Every two years, the public here in the United States has the chance to see the latest in affordable clean energy solutions as the Decathlon is on display.  This year, you can see it at the Orange County Great Park in Irvine, California, October 8-18.  Admission is no charge.

 

Photo Credit: Thomas Kelsey/U.S. Department of Energy Solar Decathlon