Trend Watch: High Yield Biofuels

We're standing in a greenhouse adjoining an unassuming industrial office complex in Thousand Oaks, California, looking up at a towering stand of switchgrass that nearly touches the ceiling above. While impressive, these plants haven't even reached their full potential. With proper genetic engineering, we're told, they can grow much taller. Other high biomass feedstocks developed here like sorghum can reach nearly 20 feet tall if provided the right growing conditions. Welcome to the world of high-tech biofuels, where the future of alternative energy sources from biomass is all about the yield.

That greenhouse is just part of the extensive Ceres Inc. biotechnology complex that Green Car recently toured. Inside the building is a maze of labs working at a rapid pace to advance the viability of agricultural technology for low-carbon, non-food, dedicated energy crops. Breaking the addiction to oil will take many forms in the coming decades and clean, renewable alternative fuel sources like cellulosic ethanol are both a short and long-term answer. According to Ceres CEO Richard Hamilton, "If oil is America's addiction, at Ceres we believe biofuels are the cure."

Unlike ethanol from food crops such as corn and sugarcane, cellulosic ethanol is made from the cell walls of plants and biowaste materials. This is an important distinction since the use of food crops for fuel production is controversial, and breaking free of this is crucial to the long-term viability of this alternative fuel. That's part of the mission at Ceres.

Ceres has taken the tools and technologies developed for the Human Genome Project, things like high throughput DNA sequencing and micro arrays, and applied them to dedicated energy crops. The company doesn't intend to grow those energy crops, but rather become a major supplier of high yield seed or germplasm to generate the millions of acres of biomass energy crops needed to make a major impact. That's not just wishful thinking: Ceres is the world's leading plant genomics company and already has over 75,000 plant genes sequenced, including some 15,000 switchgrass genes.

Those genes are used to develop plant strains that grow bigger, better, and faster with greatly improved yields. Stress tolerance for factors like poor soil conditions, harsh temperatures, and drought are also factored into the mix. The above mentioned switchgrass is a good example. Not only is the size of the plant important, but the density of plant material that can be grown in a given area is critical to breeding varieties that will deliver higher yields faster.

While switchgrass is a leading contender, it certainly isn't the only promising biofuel source. Sweet sorghums deliver a high yield and adapt quickly while also offering low water requirements. Sorghum can be harvested the same year it is planted for a quick return. Miscanthus and energycane are perennials that also have a high yield and require little maintenance.

Ceres' variety of energycane is developed for biomass density rather than sugar production like food stock canes. Miscanthus is similar, but thrives in cooler climates than energycane for a broad spectrum of growing latitudes. Short rotation winter-standing woody crops are another perennial with great potential. Perennials are plants that return year-after-year, while annuals must be replanted every year. Since the soil isn't tilled to replant each year or growing season, perennials help preserve and build topsoil and prevent erosion.

One of the common complaints about ethanol is that it requires more fossil energy to produce than the final energy output offered by the ethanol. While that may be true for some corn-based operations, it certainly isn't true for the production of cellulosic ethanol. One well respected model forecasts cellulosic ethanol eventually delivering more than 10 gallons of fuel to the customer for every gallon of fossil energy used in its production.

E85 from cellulosic ethanol and other biomass sources can have an immediate impact on our energy independence and security. Improvements in biofuel feedstocks, combined with advances in processing technology, are exciting to watch. The stakes are high in the biofuel game, but the rewards for those who deliver on the promise of clean, sustainable energy should be well worth the effort.