In October 2010, the US Navy put a riverine command boat through its paces in Norfolk, Virginia, using a revolutionary, 100% algae-based fuel. The fuel, Solajet HRJ offers an 85% reduction in carbon emissions compared to conventional jet fuel and was supplied by San Fransisco-based renewable oil company Solazyme. It has been developed to meet the exacting requirements set down for naval renewable aviation fuel. Indeed, Harrison Dillon, president and co-founder of Solazyme, asserts: "Our refining partners tell us this is some of the highest quality oil they've ever refined."
Solazyme is just one of a number of companies striving to commercialise fuel derived from algae - or microbial biofuel. In 2010, Synthetic Genomics (SGI), for example, opened a new greenhouse facility in partnership with fuel giant ExxonMobil.
The greenhouse will enhance the research and development (R&D) of algae biofuels and, according to SGI founder and CEO Craig Venter, represents an important step forward in the evaluation of algae as a renewable fuel source. "The team has already made great strides in evaluating various strains and growth conditions for algae and we are eager to continue and expand this important research as we plan for the next stages of scale up," says Venter.
If R&D milestones are met, ExxonMobil expects to spend more than $600m on the algae biofuels programme over the next decade, $300m of which will be allocated to SGI.
Algal / microbial biofuel
Microbial biofuel offers significant advantages over more traditional renewable fuel feedstocks like grain and sugarcane, for example the growing process can be conducted with little competition for space with food crops, as well as indoors, without sunlight.
While algae-derived biofuel is still rather expensive, one process is significantly increasing its commercial viability: "It's 1,000 times more productive to make oil from algae by feeding those sugar sources than by feeding light to the algae. This brings down the cost of making the fuel dramatically," relates Solazyme's Dillon.
According to Solazyme co-founder and CEO Jonathan Wolfson, algae can be fed anything "from forest residue, like wood chips, to prairie grasses, like switch grass."
"It's very clear that we have a need for clean fuels - and we now have technology, brain power and money all coming together to develop these new ways of doing things that didn't exist before," emphasises Dillon.
There are other factors that make microbial biofuels an attractive renewable option: "Our success at producing oil at our fermentation facility has proven that our process is scalable and can reduce the cost of making oil in existing fermentation facilities," points out Dillon, adding that the company's algae-based fuel "plugs right into refining, distribution and consumption infrastructure that already exists".
The biofuel can also be customised, as Dillon explains: "What we can do now is tailor the oils by chain length and saturation, to get exactly the right feedstock for a particular product."
Naval commitment to renewable fuels
The naval tests were, by all accounts, a resounding success. According to Rear Admiral Michael P. Tillotson, commander of Navy Expeditionary Combat Command, the impressive display illustrated that there is no reduction in the boat's performance when using Solazyme's algal biofuel.
"The coxswain of the boat told me he couldn't tell a difference between the biofuel mix and the normal fuel," Tillotson said. "I think that is a testament to how practical and beneficial this fuel can be for our people, our Navy and our country."
The Navy's river boat demonstration is part of a wider commitment by the US military to become less reliant on petroleum. Rear Admiral Philip Cullom, the Chief of Naval Operations' director of energy and environmental readiness, which leads the Navy's energy task force, is adamant that algal biofuel will become a US military mainstay in the coming decade, saying that the river boat demonstration was "a great example of the fleet answering the Secretary of the Navy's call … that by 2020 half of our platforms at sea would be operating on an alternative fuel other than petroleum."
The roll out of the navy's first 'green strike force' - comprising 10 ships, submarines and aircraft running on a mix of biofuels and nuclear power - will commence next year, with field deployment set for 2016.
Cullom highlights the multi-purpose nature of the Navy's drive towards alternative fuel sources, saying, "Our primary mission for Navy energy reform is to increase war fighting capability, both strategically and tactically."
"From a strategic perspective, we are reducing reliance on fossil fuels from unstable locations. Tactically, efficient use of energy resources extends our combat range and use of non-petroleum fuels assures multiple supplies are available," he continues.
Dillon highlights the importance of this partnership: "The oil that we are making in this process can be turned into US military grade diesel fuel and jet fuel. We can make - through a renewable, domestic, secure process - drop-in hydrocarbon fuel. These fuels can go into standards military platforms: jets, land vehicles and ships. This technology represents a major step forward in US national energy security."
According to Wolfson, "Our renewable oil production technology, which results in a 100% military-spec, drop-in replacement fuel from algae can be a significant component of the Navy's long term strategy to supply 50% of its energy from renewables by 2020."
In the year prior to the test, Solazyme signed three advanced biofuels contracts with the DoD. The last of these, signed a month before the test, will see the delivery of up to 150,000 gallons of on-specification 100% algal-derived Soladiesel HRF-76 fuel (the renewable version of F-76 - the primary shipboard fuel used by the Navy) for the Navy's testing and certification programme.
Wolfson says, "We are excited by the new DoD contract which calls for much larger volumes of Soladiesel HRF-76 Renewable Naval Distillate fuel, and view its signing on the heels of our successful delivery as strong validation of Solazyme's technology and of our prospects to provide meaningful quantities of low carbon fuels for our national defence."
"Reducing dependence on foreign oil is a national security imperative, and Solazyme's technology focuses on producing an abundant, domestic and renewable source for oil and fuels," Wolfson concludes.