Dallas, Texas has become the latest hotspot for renewable energy, in this case the capture and reuse of biogas from sewage. Biogas is a byproduct of the sewage treatment process and until now it has been routinely flared off at treatment plants. That’s right, until recently biogas has been treated as a mere nuisance, but the new biogas recovery operation in Dallas illustrates just how valuable this “nuisance” really is. The 4.3 megawatt facility is expected to save the City of Dallas at least $1.5 million every year.
Sewage Treatment in Dallas
The new enterprise represents the collective contributions of about 2.5 million people in Dallas and 27 nearby communities, all of which are served by the City of Dallas Water Utilities (DWU), a City of Dallas department. The DWU treatment facility has a capacity of up to 110 million gallons of wastewater daily, and like most other treatment plants it had been flaring off the resulting biogas. Thanks to the new recovery operation, Dallas is not only saving $1.5 million annually, it is also offsetting at least 60 percent of the electricity used by DWU’s operations.
Beyond Local Biogas
Aside from offsetting local electricity use, sewage biogas can also be marketed commercially to the grid. Ameresco, the same company that built Dallas’s biogas operation, is also behind the first commercial sewage-to-biogas project in the U.S., which is located in San Antonio, Texas. This could be just the tip of a very big iceberg, as researchers from Newcastle University in the U.K. have crunched the numbers in terms of producing liquid biofuel from sewage in the U.S., and they’ve come up with a startling energy equivalency of about 12.5 trillion gallons annually. In any case, between Dallas and San Antonio it looks like Texas is hot on the trail of yet another renewable energy trend.
Image: Sewage treatment plant by eutrophication&hypoxia on flickr.com
- U.S. Flushes 12.5 Trillion Gallons of Energy Down the Drain Every Year (cleantechnica.com)
- Legendary Sewers Could Provide Renewable Heat for Paris (cleantechnica.com)
Tina Casey specializes in military and corporate sustainability, advanced technology, emerging materials, biofuels, and water and wastewater issues. Tina’s articles are reposted frequently on Reuters, Scientific American, and many other sites. You can also follow her on Twitter @TinaMCasey and Google+.