When I was in Norway a few months ago, I was talking to an official from their research council about the Norwegian national nanotechnology strategy. He explained how they were going to focus on a few appplication areas for nanotechnology, starting with nanotechnology for energy, nanotechnology for medicine, and nanotechnology for information technology. Thus far his list was very similar to lists being compiled by just about everybody else in the world. Then he went on to explain that the fourth area would be nanotechnology for fish and I had to admit to myself that the latter focus probably would be nationally distinctive. Fish apart, there does seem to be a widespread consensus that the other three areas are the ones in which nanotechnology is likely to make the biggest global impact, at least on the short to medium term. It’s worth summarising some of the arguments for this order of priority.
1. Nanotechnology for a sustainable energy economy. This comes first because our current way of life is utterly dependent on cheap and abundant energy, and there are no easy ways of significantly lessening this dependence. Yet the cheap energy that we’ve come to rely on is threatened in multiple ways. The need to reduce CO2 emissions to combat climate change is growing in urgency, the geopolitical implications of such a vital commodity being in the control of people and nations whose interests may not be the same as ours are becoming more and more obvious, and the prospect of the exhaustion of the most convenient forms of fossil fuel – gas and oil – is appearing on the horizon. It’s no surprise, the, that both private sector investments and government funded research in nanotechnology is increasingly being directed in applications to energy.
So, how could nanotechnology make an impact on our evolving energy economy? Let’s look at this in three categories:
1. Primary energy sources. At the moment, the ultimate sources of most of our energy are oil and gas, either used directly or converted into electricity, and electricity made by burning coal or by harnessing nuclear fission. Renewables – primarily hydroelectric at the moment, with wind power growing, make a small contribution. Nanotechnology’s most significant potential contribution is in the area of solar energy, where alternative photovoltaics capable of being produced cheaply in the very large areas needed to supply significant amounts of power are on the horizon.
2. Energy for transportation. Our societies are dependent on large scale mobility, both personal and for the movement of goods across the world. Liquid hydrocarbons – in the form of petrol, diesel and aviation kerosene – are convenient, high energy density fuels, and a massive infrastructure exists to distribute them. The “hydrogen economy” offers an alternative, in which the transport fuel would be hydrogen, made using primary energy sources like solar energy, nuclear energy, or a combination of fossil fuel use with CO2 sequestration. Nanotechnology could help overcome some of the formidable technical barriers to this scheme, by making possible safe, high density storage for energy and by improving the performance and price of fuel cells. On the other hand, as the recognition of the economic and technical barriers to a hydrogen economy grows, the alternative of a “methanol economy” grows more attractive in some people’s eyes. Using methanol as a transportation fuel has the great advantage that one can use the existing infrastructure for distributing liquid fuels, and continue to use internal combustion engines. An ideal would be to make methanol directly using solar energy to combine water and carbon dioxide – photocatalytic reduction of carbon dioxide. This is something we know ought to be possible in principle, but we don’t know how to do it yet.
3. Lowering the energy intensity of the economy. There are a host of possible incremental improvements in materials and processes to reduce the amount of primary energy needed to produce a given amount of economic output. Individually these may not look spectacular, but together the effect may be very significant. This ranges from more efficient light sources such as light emitting diodes, better materials for building insulation to better materials and coatings allowing turbine blades to be operated hotter, leading to higher energy conversion efficiencies in power stations.
Next – nanotechnology for medicine and health