Physicists, Algae and Sustainability

A couple of weeks ago my university was able to announce a large new initiative, £20M to set up The Winton Programme for the Physics of Sustainability, funded by David Harding, the founder, chairman and head of research of Winton Capital Management and an alumnus of my department.  The details of this enterprise, which will be led by Professor Sir Richard Friend, are still to be worked up, but I think it is reasonable to assume that a significant amount of the effort will be directed towards novel and improved methods for energy production, applying physics to meet the growing demand on our natural resources.

However it is easy for physicists to think in purely ‘synthetic’ terms when dealing with problems such as these. By this I mean a natural area to concentrate effort on would be organic photovoltaic devices of the kind to which Friend has already made such a significant contribution.  He has recently a third spinout to his name in conjunction with the Carbon Trust; Eight19,  a new solar energy company – spun out from Carbon Trust’s Cambridge University-TTP Advanced Photovoltaic Research Accelerator – which will be focusing on developing and manufacturing high-performance, low-cost plastic solar cells for high-growth volume markets.  In my own very small way I am involved with a different project aimed at exploring optimization of devices composed of blends of semiconducting polymers by getting a better grip on the underlying polymer physics of the morphology development during device processing. This project is a collaboration involving Sheffield University, Diamond and Cardiff University.  Sheffield University has its own substantial effort directed at sustainability, Project Sunshine, which has three themes: food, energy and global change. Their description of the energy section identifies two different strands to utilize solar energy: photovoltaic devices such as those studied in the EPSRC project I am involved with or relevant to Eight19, and microalgae as the basis of biofuel production.

The latter may look as if it is far removed from physics – the project, part of a large consortium and also funded by the Carbon Trust – requires optimizing both the strain of algae used and the efficiency of lipid production as well as developing refining methodologies to produce the requisite biofuel.  But as with biofuels produced on land (which have recently come in for much opprobrium because they take land away from food production and their net effect on carbon emissions is unclear), there is much more scope for biological physicists to make a contribution than is perhaps immediately obvious.

Why do I say this? Some years ago I was involved with an unsuccessful bid to BP for their Biofuels Institute, a bid won by the University of California, Berkeley after significant commitments from their Governor Arnold Schwarzenegger. (The Institute may now be something of a poisoned chalice on many fronts; I have no information that tells me this is so but given the  image of BP in the US and the financial situation of the state of California, quite aside from the fall from grace of biofuels produced from crops nicely described a couple of years ago by Richard Jones here,  one must assume this is so.) As people got together to start preparing our university’s case the obvious suspects were lined up: plant scientists, engineers and chemical engineers, social scientists and those involved with policy. But physical sciences collectively were thought not to be relevant. I objected (and was immediately co-opted onto the working group) because, if using plant mass (biological) physicists have relevant tools to study structure and how that varies between candidate species or cultivars. This knowledge can then be used to provide understanding of how the structure affects processing, rather than tackling this in an empirical way in large vats as might be done in a chemical engineering department. In other words, I would say that by providing underpinning mechanistic understanding, physicists can help to rationalize an optimized strategy even for feedstock of  biological origin.

In fact, it is exactly this same strategy of rationalization which underpins the work I am involved with on organic photovoltaics: many approaches in the literature rely on annealing appropriate polymer blends to modify the microstructure and then examining subsequent device performance, without having a robust underpinning understanding of the thermal properties of the polymers involved. In other words they don’t have a firm grip on where the glass transition temperature and other relevant thermal transitions sit to identify an appropriate processing (annealing) window.  By gaining a better understanding of the properties of the constituents, we believe we can provide better a priori insight into what thermal annealing will be best to give the desired microstructure. I believe in a similar way, with plants or algae, by understanding the structure (and not just the chemistry) of the feedstock it may be possible to identify which sources will be most easily broken down or how growth conditions affect microstructure and therefore subsequent processing strategies.  My work on starch (outlined on my blog previously) shows that a physicist can contribute surprisingly much to inform both plant breeders and industrialists utilizing the material, and I would be surprised if physicists – of either a biological or polymeric bent –  were not similarly able to contribute to research aimed at optimizing algae utilization for biofuel production.  That of course will not resolve the bigger issues of whether this route is viable commercially – though if it helps in the optimization it may help to bring costs down – let alone whether it is actually effective in reducing CO₂ emissions overall, but if algal biofuel production is to succeed as a realistic option the whole spectrum of potential research inputs must be utilized. Once again the breadth of interdisciplinary science needs to be borne in mind and I hope physicists will form part of the teams and consortia set up to explore these novel routes to biofuel production.