Cleaning up with renewable energy

  • Published
  • By Amy Ausley and Susan Walker
  • AFCESA, AFCEE
TYNDALL AIR FORCE BASE, Fla. --  When the Air Force has an environmental remediation project on its hands, it can mean high costs and lots of energy use. Many of the sites are located in remote areas and are not supported by the power grid. Getting power to an environmental clean-up project can be a logistical nightmare, but the use of renewable energy is taking some of the sting out of environmental remediation projects by making them more cost effective and energy efficient.

The use of renewable energy is one aspect within a broad category of technologies labeled green and sustainable remediation, or GSR.

One of the most notable and visible Air Force environmental clean-up projects using renewable energy is underway at the Massachusetts Military Reservation. Three 1.5 megawatt wind turbines provide 100 percent of the power needed to clean more than 12 million gallons of ground water a day. The Air Force is also using solar-powered remediation systems at 13 other sites across the nation, which will produce at least 4.7 kilowatts when fully functional. Most of the projects are smaller-scale or pilot projects and many of these sites having non-permanent solar arrays that are removed after completion of the study.

One of the pilot projects showing promise is a solar-powered recirculation system treating ground water contamination at Air Force Plant PJKS, Systems and Components Area, in Colorado. The former Air Force property is now owned by Lockheed Martin. The site was originally the testing ground for the Titan missile, and as the original owner, the Air Force is responsible for the clean-up. The clean-up technology is demonstrating an effective use of a renewable energy source and turning out better than expected GSR results. The clean-up performance of this system will be evaluated for at least another year, but could move to full-scale remedy if results continue to be favorable.

Another approach to reduce energy use in the clean-up program for Air Force is the use of more passive treatment technologies. Examples include monitored natural attenuation, bioremediation using natural materials such as vegetable and mulch, passive soil vapor extraction, and using plants to extract or treat contaminants in groundwater. These technologies are not necessarily dependent on a continuous energy source, such as a pump and treatment system would require, and rely more on natural processes within the soil and groundwater to breakdown the contaminants.

GSR policies and practices have been developed or are in development by a variety of state, federal, military, and private entities, as well as international groups. Executive Order 13514, 'Federal Leadership in Environmental, Energy, and Economic Performance' has been a means to emphasize the availability and benefit of green remediation technologies and practices to the federal government.

The Interstate Technology and Regulatory Council, an organization with representatives from all 50 states, the District of Columbia and multiple federal and industry organizations, is working to make things a little easier when it comes to environmental projects. They created a project called Green and Sustainable Remediation, which outlines how to plan, implement and close out a remediation project while considering environmental, social and economic factors.

Using renewable energy for environmental clean-up sounds like a potential solution, but it's not the answer for every project. A new tool is in development to help determine the best solution for each installation. Researchers from the Air Force in conjunction with industry created two products to help determine if a renewable energy source is the answer to an environmental clean-up issue. The first is the Sustainable Remediation Tool, which allows users to estimate sustainability metrics for specific technologies for soil and ground water remediation. Dr. Paul Jurena of the Air Force Center for Engineering and the Environment's Technical Support Division, who oversees SRT, said, "This free, easy-to-use, Excel-based tool allows you to evaluate your particular remedy to see if you can use GSR remedies at your site."

The second tool, CleanSWEEP, or Clean Solar and Wind Energy in Environmental Programs, is scheduled to be finalized in September. CleanSWEEP assesses the potential to switch from non-renewable energy to renewable energy to power remediation systems. It also evaluates the potential of using renewable energy based on a site's location away from the power grid. Jurena says this new tool may have uses beyond environmental remediation.

"Many people have expressed interest in using CleanSWEEP, not only for environmental restoration sites, but for other site uses as well," he said. "If you're off the grid for any type of project, why not have a tool to evaluate your power need? Just enter your power requirements and list the percentage of wind and solar you want to use. It will evaluate your location and determine whether renewable energy is feasible and economical - or not - for the power requirements of your site."

With the proper evaluation tools in place and the data beginning to show good results, renewable energy could be the wave of the future for environmental remediation.

For more information about the SRT, visit http://www.afcee.af.mil/resources/technologytransfer/programsandinitiatives/sustainableremediation/srt/index.asp.
To contact the SRT and CleanSWEEP team at AFCEE, email afcee.ttoo@us.af.mil. (Ausley is with the Air Force Civil Engineer Support Agency and Walker is with the Air Force Center for Engineering and the Environment)