Editor's note: This Q&A is a part of a survey conducted by Scientific American of executives at companies engaged in developing and implementing non–fossil fuel energy technologies.

What technical obstacles currently most curtail the growth of biofuels? What are the prospects for overcoming them in the near future and the longer-term?
For plant oil–based biofuels, such as jatropha, the main obstacle is the lack of research and practice in large-scale commercial cultivation, as well as mechanized harvesting. Currently most jatropha and castor are grown on smaller, independent farms. The second obstacle is yield and unit of input. Research in plant breeding needs to continue in order to improve the quantity and quality of oils being produced. We are currently working to bring feedstocks such as castor and jatropha to a commercial scale, making them more feasible for use in transportation, as well as power generation and specialty chemicals.

The dip in the price of petroleum has dampened the urgency for developing alternative sources of energy, but we are confident that this is the calm before the storm. Prices will rise again, and we need to continue to be focused on developing long-term solutions to replace our dependence on petroleum. Developments with mechanized harvesting are progressing and we anticipate results in two to four years. Using crops like sugar and corn as a guide, we can expect order-of-magnitude improvement every five to seven years.

Are there obstacles to scaling up biofuels to serve a larger national or global customer base?
In general, constraints to growth are land, labor, water and need for quality planting materials. For the feedstocks we develop, land and labor are not an issue. There are vast areas of land available that are not suitable for use as food crops and labor is available in developing countries. Water can be a limiting factor, but research into plant breeding continues to develop drought- and saltwater-tolerant crops. Freshwater-harvesting technologies are also being implemented.

Much research needs to be done, but we are on the right track. We believe that there will be no one single solution to our energy problems. It is important, though, that our main focus be on using feedstocks that are grown in areas that are not used for food crops. This is key in ensuring cultivation that is responsible and sustainable.

Can the existing energy infrastructure handle growth in biofuels? Or does that, too, need further modification?
For the transition to biofuels to be successful, we need to ensure that as little modification as possible is needed. In order for this movement to work, biofuels need to work within existing infrastructure in order to truly be scalable.

Given the current economic crisis, can your industry get the necessary capital (from public or private sources) to adequately finance its growth?
Obviously, this is a difficult time for any industry, but we believe that despite the economic climate, we cannot allow ourselves to be deterred. Fortunately, many others feel the same way, and we are hopeful. We are encouraged by recent collaborations with Boeing, Air New Zealand, Continental Airlines and Japan Airlines. These developments energize people to invest in our collective future, and the well-being of our planet, despite the economy.

From a strategic standpoint, which is the bigger competitor for biofuels: incumbent coal, oil and gas technologies or other alternative energy technologies?
The market is so large that any one technology is unlikely to represent a significant share of petroleum. All emerging technologies are helping to pave the way to a reduced-petroleum future, and there is no single solution to our dependence on fossil fuels. Currently, traditional industry and vested interests are the biggest competitor to the growth of biofuels.

Is there a cost target that you and others in your industry are aiming to achieve in, say, five years?
Biofuels need to be competitive with fossil fuels in the next five years, taking into account petroleum subsidies and a comprehensive systems for pricing emissions.