Think small to grow big

Nanotechnology is not just for use in the future. Rob Fastenau argues that it has a role to play now in meeting our energy needs.

As energy demands increase and our ability to supply using traditional methods declines, we must not underestimate nanotechnology’s role in the production, storage, conservation and delivery of energy.

There are two ways to address a gap between energy supply and demand: the development of inexpensive and earth-friendly alternative fuel sources and using existing fuels more efficiently. Nanotechnology has a fundamental role to play in both.

At the nanoscale, familiar materials begin to develop unusual properties because this is the level where essential properties of matter are determined. Applying these properties can help find new ways to manage energy supplies.

For instance, the Pacific Northwest National Laboratory (PNNL) in the US is using nanotech to develop materials that can store solid hydrogen. Hydrogen is abundant in our atmosphere and has more energy per unit of mass than any known substance but there are technical barriers to realising the hydrogen economy – the greatest being storage.

In its gaseous state hydrogen’s energy content is low. The challenge is finding a way to store it which maximises the energy available while ensuring it can be processed to generate power. By manipulating solid hydrogen atom by atom, it can be stored in nanoscale pores built into PNNL’s new material. At this scale, the hydrogen retains its solid state and can easily be transported. The material can be broken down, releasing the hydrogen for processing.

Target for wind power

Nanotech can also support wind power. There are 1,672 operational turbines in the UK developing an annual 1,833MW. That number must rise to 40,000MW before 2010 to meet European directives on renewable energy.

Reliability is a major problem. Wind turbines are huge, rotating objects often operating in wet conditions. They can accumulate rain and sea water that freezes into ice, increasing weight, drag and the force required to move glass fibre blades. Turbine efficiency can drop by up to 10 per cent under these conditions. But new coatings, built atom by atom, can help blades repel water.

The Degussa Corporation in Germany is using nanoscale wax crystals to replicate water-repellent surfaces found on plants. It can now manufacture these as a thin film that quickly beads water and can be used on turbine blades to make water run off before it can freeze.

Another example is the development of cheaper solar panels to encourage more people to invest in solar power. Nanotech is helping reduce the cost of producing solar panels by removing the need to build them from silicon. Thin films of new photovoltaic substances just one nanometre thick can generate as much electricity as a 200-300nm thick silicon wafer for a lower cost. One company, Nanosolar, is planning to build a new production plant in Germany, producing 200 million nanotechnology solar cells per year – enough to power 400,000 homes. It claims a silicon-based factory of the same capacity would cost an additional $900m (480m).

Elsewhere, the materials science department at CambridgeUniversity is developing nanotechnology that could reduce the UK‘s electricity consumption by 16 per cent by bringing white light-emitting diodes (LEDs ) into our homes and offices.

About 95 per cent of the energy used in traditional lighting is wasted in the form of heat, but LEDs are up to 10 times more efficient because they do not require heat. LEDs used in torches, however, produce a light too harsh for our eyes. Cambridge is covering LEDs with phosphor nanoparticles – substances that emit different colours when subjected to white light. When different phosphors are used in a particular combination on white LEDs they produce natural white light suitable for homes and offices.

Elsewhere, travel company Stagecoach is using nanotech to increase the fuel efficiency of its coaches and buses. Oxonica, a small company based in Oxford, has developed a fuel additive built using nanoscale particles called Envirox. It coats the inner workings of engines, removing carbon deposits during combustion, and has demonstrated fuel efficiency gains of up to 12 per cent and significant reductions in particulate emissions.

Exploiting traits

Future electricity grids could be built on nanoscale science. Carbon nanotubes are better conductors of electricity than traditional copper wires. They can carry more than one billion amps/sq cm, losing little energy as heat, and in theory could carry electricity thousands of miles. With the ability to conduct electricity over these distances, cities could draw power from giant desert solar farms or off-coast wind farms rather than rely on local coal, gas or nuclear plants.

There are a finite number of energy sources on the planet but measurable ways to improve our use of them. By viewing substances atom by atom we will understand how best to exploit their traits. By manipulating them at this scale, we can develop energy-efficient materials and products. If we continue to label nanoscience and the new technologies it can yield as developments for the next century we are likely to overlook its immediate advantages. Nanotechnology is not a discipline for future generations. It can help us now.

Dr Rob Fastenau is senior vice-president, Europe, FEI Company