Behind the buzz and beyond the hype:
Our Nanowerk-exclusive feature articles
Posted: Jul 16, 2007
Nanotechnology's potential to reduce greenhouse gases
(Nanowerk Spotlight) By now we all are aware of the issues concerning greenhouse gases and climate change, so there is no need to repeat them here. Rather, we will take a look at the areas where nanotechnologies could have a beneficial environmental impact - especially with regard to reducing greenhouse gases - above current technologies, and the barriers potentially preventing their adoption. A study commissioned by the nanotechnology group of the UK's Department for Environment Food and Rural Affairs (Defra) looked into the the policy implications of nanotechnologies that will benefit the environment. The report of the study, "Environmentally beneficial nanotechnologies: barriers and opportunities", investigates the opportunities and potential obstacles to adoption of a number applications of nanotechnology which could be used to cut use of non-renewable energy sources and reduce greenhouse gas emissions. Five nanotechnology applications were subject to detailed investigation: fuel additives, solar cells, the hydrogen economy, batteries and insulation.
Unfortunately, the study focuses exclusively on the UK. Nevertheless, the projected benefits are quite impressive and it wouldn't be too difficult to make some back of the envelope type projections for other industrialized countries, especially the U.S., the biggest greenhouse gas producer in the world.
The study concludes that nanotechnology is likely to have a significant positive effect on the UK's green house gas emissions: "From the areas we have studied, nanotechnology could reduce our green house gas emissions by up to 2% in the near term and up to 20% by 2050 with a similar saving being realized in air pollution. These savings are based on the wide-scale adoption of nanotechnology and the assumption that predicted breakthroughs within the field will occur when expected."
Summary of the impact of environmentally beneficial nanotechnologies in the UK. Footnotes: 1) Impact of nanotechnology describes the effect nanotechnology is likely to have in the area compared to other technologies. 2) Infrastructural changes indicates the effort bring the nanotechnology to market. 3) Benefit is the estimate of the maximum potential CO2 saving by implementing the technology. 4) Timescale for implementation is the projected distance (in years) before the technology will be fully implemented. (Reprinted with permission from Oakdene Hollins)
The authors state that, initially, these effects are likely to be the result of large numbers of small innovations. "An R&D infrastructure that allows the development of good science into a commercial product is important. Public procurement and policy can be used (with caution) to act as a
market pull for environmentally beneficial nanotechnologies."
Here is the report's summary of findings and recommendations with regard five key nanotechnology application areas:
Nanoparticle additives have been shown to increase the fuel efficiency of diesel engines by approximately 5% which could result in a maximum saving of 2-3 millions of tonnes (Mte) per annum of CO2 in the UK. This could be implemented immediately across the UK diesel powered fleet. However this must be tempered by concerns about the health impact of free nanoparticles in diesel exhaust gases.
Recommendations include: Comprehensive toxicological testing and subsidized independent performance tests to validate environmental benefit.
Nanotechnology may deliver benefits in significantly decreasing the cost of production of solar cells. Conservatively, if a distributed solar generation grid met 1% of the UK's electricity demand, approximately 1.5 Mte per annum of CO2 could be saved. The major barrier to this technology is the incorporation of the nanotechnology into the solar cell, not the nanotechnology itself. The UK is one of the world leaders in understanding the fundamental physics of solar cells, but there is a lack of skills to transfer the science base into workable prototypes.
Recommendations include: Develop programs and facilities for taking fundamental research through to early stage prototypes where established mechanisms can be employed to commercialize new technologies. Develop center of excellence in photovoltaics which allows cross fertilization of ideas from different scientific disciplines.
The hydrogen economy
Hydrogen powered vehicles could eliminate all noxious emissions from road transport, which would improve public health. If the hydrogen were generated via renewable means or using carbon capture and storage, all CO2 emissions from transport could be eliminated (132 Mte per annum). Using current methods of hydrogen generation, significant savings in carbon dioxide (79 Mte per annum) can be made. The hydrogen economy is estimated to be 40 years away from potential universal deployment. Nanotechnology is central to developing efficient hydrogen storage (which is likely to be the largest barrier to wide scale use). Nanotechnology is also a lead candidate in improving the efficiency of the fuel cells and in developing a method for renewable hydrogen production.
Recommendations include: Consider the use of public procurement to fund hydrogen powered urban public transport to create a market and infrastructure for
hydrogen powered transport. Continue to fund large demonstration projects and continue R&D support.
Batteries and supercapacitors
Recent advances in battery technology have made the range and power of electric vehicles more practical. Issues still surround the charge time. Nanotechnology may provide a remedy to this problem by allowing electric vehicles to be recharged in much more quickly. If low carbon electricity generation techniques are used, CO2 from private transport could be eliminated (resulting in a maximum potential saving of 64 Mte per annum) or, using the current energy mix, maximum savings of 42 Mte per annum of carbon dioxide could be made. Without nanotechnology, electric vehicles are likely to remain a niche market due to the issues of charge time [Nanowerk comment: for everyone who saw the movie "Who killed the electric car?" this statement doesn't make sense; it appears to be more a industry lobby/political will issue than a battery technology issue]. Significant infrastructural investment will be required to develop recharging stations throughout the UK.
Recommendations include: Fiscal incentives to purchasers such as the congestion charge scheme, fast track schemes for commercialization and cultivation of links with automotive multinationals.
Cavity and loft insulation are cheap and effective, however, there are no easy methods for insulating solid walled buildings, which currently make up approximately one third of the UK’s housing stock. Nanotechnology may provide a solution which, if an effective insulation could be found with similar properties to standard cavity insulation, could result in emission reductions equivalent to a maxim potential of 3 Mte per year. Ultra thin films on windows to reduce heat loss already exist on the market. There are claims that nano-enabled windows are up to twice as efficient as required by current building standards. However, industry believes that significant further insulative savings in glass maybe made instead using aerogels, which themselves are nanostructures.
Recommendations include: Fund a Technology Program call on novel insulation material for solid walled buildings and include in government estate
procurement specifications highly insulating nanotechnology based windows.
The report concludes that the near-term effects of nanotechnology are significant, yet incremental. "The long-term predictions for some of the technologies are larger, but they probably underestimate technological advances in non-nanotechnological innovations. Overall though, the potential advances brought by nanotechnology justify continued interest in the area."