Google Hitches a Ride on Wastewater's Quiet Revolution

Google has been operating a municipal wastewater recovery and recycling system to cool its Douglas County, Georgia data center for the past couple of years without much fanfare, up until last week when its facilities manager decided to post a video about the system on googleblog. The short post unleashed a flood of snickering and potty references across the blogosphere but really, Google has barely scratched the surface of wastewater’s emerging role in the clean energy future.

There is more. Much, much more.

Google's energy efficient cooling system

To recap: Google’s cooling system, of course, does not use untreated wastewater straight from the locals’ pipes. In 2008 the company worked with the Douglas County public water utility to build a new auxiliary treatment plant, which takes in up to 30 percent of treated water from an existing treatment plant (the rest of the water from the existing plant is discharged into the Chattahoochee River, so it's pretty clean to begin with).

At the auxiliary plant the water receives further processing before heading into the data center, where it is used as a coolant in lieu of energy-sucking machinery. The cooling system yields water vapor and excess water, which gets another round of treatment before finally being discharged to the Chattahoochee.

Biogas recovery from wastewater

Reclaiming treated wastewater and sending out for use as an energy efficient coolant is all well and good, but a whole other side of the sustainability equation is taking place right there at treatment plants, in the form of biogas recovery.

Modern treatment plants use a carefully calibrated natural microbial process to digest and break down human waste and other organic material, and that natural process gives off copious amounts of natural gas. In the past, treatment plants routinely flared off biogas for safety and odor prevention, which also converts the methane in biogas into a less potent greenhouse gas.

More recently, treatment plants have begun to capture biogas and use it as fuel for keeping the digestion process environment at an optimal temperature, or to generate electricity that can be used to run pumps and other equipment.

Turning wastewater biogas into hydrogen fuel

Reclaiming biogas for direct use in energy production at treatment plants is  becoming fairly commonplace, but just last week the Pennsylvania-based global company Air Products stepped things up yet another notch by announcing a plan to throw renewable hydrogen generation into the mix.

Air Products makes gasses and other products for energy related systems and solar panel manufacturing, and it is teaming up with another U.S. company called FuelCell Energy for the commercial development of a proprietary fuel cell called Direct FuelCell®. The new fuel cell uses natural gas - including biogas from wastewater treatment plants - to generate hydrogen along with usable heat and electricity.

Hydrogen fuel and the Obama Administration

The use of renewable biogas is noteworthy because hydrogen fuel cell vehicles play a significant role in President Obama’s “all of the above” energy  strategy, which focuses on domestic sources with an emphasis on local energy production. Ideally the hydrogen would be manufactured by renewable energy sources including solar and wind power as well as biogas (rather than drilling for gas, which can involve certain unsavory consequences.

In the Direct FuelCell®, methane reforms into hydrogen to produce electricity. The high efficiency process generates more hydrogen than it needs to produce electricity, so the excess hydrogen can be employed in any number of other industrial processes, including the refueling of hydrogen fuel cell vehicles.

FuelCell Energy is already operating one such fuel cell system under a subcontract with Air Products in California at the Orange County Sanitation District wastewater plant in California, complete with a hydrogen vehicle fueling station.

With the new partnership, Air Products and FuelCell Energy will be developing the Direct FuelCell® as a standard model, aiming for the global market.

Google searches for new energy frontiers to explore

As for Google, the company has already begun venturing into biogas territory, rounding out its previous forays into solar power, wind farms and geothermal energy. Last year Google began funding a hog waste treatment plant developed by Duke University and other partners including the U.S. Department of Agriculture.

Along with biogas, the plant will produce treated wastewater that may be suitable for reuse in cleaning the hog houses, for irrigation, or for that matter, as a coolant for data centers.

Image: Water by Dori, Wikimedia Commons.

Follow Tina Casey on Twitter: @TinaMCasey.