The Fine Print On Nanotech

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Federal governments of both persuasions have been keen to portray nanotechnology as "clean and green".  The title of this 2002 report (pdf), "Smaller, cleaner, cheaper, faster, smarter" is typical.

With nanotechnology, the industry has promised, we can have our cake and eat it too — environmentally benign economic expansion, a future of high tech prosperity, new gadgets and gizmos, an end to hunger and poverty… Yet like many things that sound too good to be true, the recent Friends of the Earth report reveals that nanotechnology’s green claims do not stand up to scrutiny. The nanotech industry has consistently over-promised and under-delivered.

Despite impressive laboratory discoveries in the renewable energy sector, it has all too often been impossible to incorporate these properties in mass-produced products that will actually save energy and be affordable to produce. For starters, see here and here.

In the much-touted field of nano solar, the solar conversion efficiency of nano solar cells remains about 10 per cent lower than that of traditional silicon panels. The durability of some commercial nano solar panels, for example those plastic cells manufactured by Konarka is as low as 3-5 years, compared to 25-30 years for silicon panels.

A group of US researchers has cautioned that amid the buzz surrounding nano solar are "questionable claims on the scientific facts". They suggest that better outcomes would be achieved through greater economies of scale in producing conventional silicon panels. Recent analyses have revealed that the energy demands of manufacturing nanoparticles are much higher than expected. This sheds doubt on whether other nano-applications that are designed to save energy will actually deliver.

For example manufacturing carbon nanofibres uses up to 360 times the energy to make steel, on an equal mass basis. Proponents have suggested that by strengthening windmill blades with carbon nanofibres, the blades will be lighter, reducing wear and tear and increasing the efficiency of energy generation. However because of the energy required to manufacture the nano blades, early life cycle analysis shows that it may be just as energy efficient to use conventional windmill blades.

Similarly, one of the booming applications of nanotechnology is in the use of antibacterial nanomaterials in work wear, socks and other clothes. The idea is that nanoparticles of silver kill bacteria that cause odour, laundry frequency is reduced, and energy saved. The trouble is that not only does the nano silver pose new toxicity risks, the energy associated with producing it may mean that the products come at a net energy cost.

A Swiss researcher calculated that the life cycle energy costs associated with nano silver T-shirts were greater than conventional T-shirts in two out of three scenarios. Only if there was substantial behavioural change (far less clothes washing) did the nano silver T-shirt use less energy.

There is also a question mark over how much attention (and research funding) is really being directed to nanotechnology applications that could offer environmental benefits — compared to those that simply offer new marketing opportunities.

Nanoproducts that dominate current sales and product inventories, such as cosmetics, personal care products and sports equipment, are not only energy intensive to manufacture, but offer no potential for energy savings through their use. The United States President’s Council of Advisors on Science and Technology reports (pdf) that in 2008 only 1 per cent of nanotechnology-based products came from the energy and environmental sector.

Marketing of nanotechnology as "clean and green" is undermined by the world’s biggest petrochemical companies using it to find and extract more oil and gas. Halliburton, Shell, BP, Exxon Mobil and others hope that nanotechnology may as much as double the amount of oil able to be extracted from known reserves.

Despite the green rhetoric of successive Australian governments, public funding in Australia (through the CSIRO (pdf) and universities) also supports nanotechnology research to find and extract more oil and gas.

As we confront climate change, making smart technology choices is vital. In many instances making decisions to change technologies — for example to abandon coal-fired power and to embrace renewables — will have a significant bearing on our ability to rapidly reduce greenhouse gas emissions.

But will new technologies support such dramatic gains in energy generation and efficiency that they will enable "business as usual" growth? A closer look suggests that it is highly unlikely.

By 2070 there may be nine-plus billion people on the planet. Ted Trainer makes the point that if all of them have the "living standards" Australians are predicted to have by then, assuming 3 per cent annual growth from now, total world economic output would need to be 60 times greater than it is now.

Clearly, reducing the demand for energy is as important as seeking sustainable ways to satisfy that demand. As we consider which technology choices offer the most potential to meet the challenge of climate change, rather than taking the green claims of proponents at face value, we need good information about the true life cycle energy and greenhouse gas emissions of the alternatives.

When new technology sectors tout their environment credentials in an effort to win both public hearts and minds and generous research funding, those industries have a responsibility to demonstrate that their green claims stack up.

Public funding should be prioritised to areas that offer immediate potential to reduce greenhouse gas emissions, while not imposing new environmental burdens. Public funding should not be directed to applications that prolong our reliance on fossil fuels. While research in cutting edge sectors will continue, it is vital to ensure that this is not at the expense of pursuing less glamorous near-term measures to tackle climate change.

The most effective way to rapidly reduce greenhouse gas emissions may be to support scale up of existing renewable technologies, such as solar thermal and wind, and invest in infrastructure to reduce the carbon intensity of industry and transport, rather than pinning our hopes on a cutting edge new technofix that lies forever around the corner.

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