Green fuels could keep soldiers fighting

A report from America suggests that soldiers could make fuel and electricity on the battlefield instead of relying on long supply chains to transport energy to them.

A report from the National Research Council’s Board on Army Science and Technology claims that future US Army operations in the field could rely on alternative fuels and biological methods to produce electricity through photosynthesis.

‘The real issues for the Army are the ability to simplify logistics requirements, to remain flexible with battlefield fuels, and to capitalise on alternative fuels, such as methane, instead of restricting ourselves to fossil fuels,’ said Robert Love, study director for the National Research Council. ‘With fossil fuels, logistics can become difficult because you have to have this long supply chain.’

Scientists are already working on making fuel from waste plant materials such as cellulose and hemicellulose. Grasses, surplus grains, spoiled food; food wrappers, paper or even cotton cloth could be converted into fuel using this method.

‘In theory, these materials could be produced in the field (if the theatre of operation were in a temperate zone) and used as fuels,’ the report stated.

‘The Army needs to be investigating surrogate fuels, such as ethanol and biodiesel, and make sure their engines can run on a variety of fuels,’ said Purdue University’s Michael Ladisch. ‘Actually, I think this can be done with a minimal amount of modification.’

Another energy need for modern soldiers in the field is electricity, and batteries are bulky and very heavy. Biological systems may provide a solution, the NRC committee suggested.

‘Right now the Army is dependent on batteries, and they can’t take seriously other energy sources such as solar power,’ said Love. ‘One of the things the report investigated was photovoltaic energy, and how bioelectronics might make it possible to increase the efficiency of converting sunlight to usable energy.

‘If you put this together with fuel-cell storage techniques, this would have a large impact on how the military operates, especially for small unit operations.’

The NRC recommended that the Army investigate how plants convert photons to energy because plants are so good at grabbing energy from the natural environment. Millions of years of natural selection has optimised plants to the particular wavelengths of sunlight, and because of this, plants convert 98 percent of the sunlight they receive into energy.

Conversely, current solar energy systems are only 10 percent to 15 percent efficient.

The NRC report recommended that coupling the light-harvesting capabilities of plants with protein-based devices could lead to solar energy systems capable of converting solar energy at 40 percent to 50 percent efficiency.

The report’s authors also envision protein-based photovoltaic coatings on the Kelvar military helmets that could produce enough energy for the soldier’s electronics. Other equipment and vehicles could also be covered with these protein-based solar converters.

A side benefit of such technology, the report noted is that the protein coatings would make whatever they coat more difficult to detect by electronic means since they would mimic the natural environment.