As Mr. Darshan Goswami puts forth in his article on EnergyPulse, “Nanotechnology is an evolutionary science combining engineering and chemistry for manipulating materials at the atomic and molecular level to develop new or enhanced materials and products. The term covers many areas of research dealing with objects that are measured in a billionth of a meter or nanometers (or ten to the power minus nine). Nanotechnology involves the study of molecular and atomic particles, and manufacturing nanoscale materials and devices”.
But more precisely, nanotechnology is a term first coined by K. Eric Drexler in 1986, in the book Engines of Creation, the term refers to the manipulation of matter of scale on the nano – meter (one – billionth of a meter). The goal of nanotechnology is to control individual atoms and molecules to create computer chips and other devices that are thousand times smaller than current technologies but far more effective, faster and reliable. There are many other definitions for the same but it can be called a permutation and combination of the above.
With power sectors across the world facing the most difficult energy market in the last two decades, India has not been left out. With GOI considering and going for privatization, there has been a humongous hue & cry over the rising prices and the shortfall of supply with respect to the demand. The gap between the supply and demand has been on a steady rise. With fossil fuels ready to expire within a few years, there would be a pandemonium across the world. What are you going to do then? Energy being a basic necessity, it will be impossible to realize a life without it, it would be like going back to the Dark Ages, it would be like history repeating itself.
Oil price volatility has experienced record swings, and the future of the Middle East, home to 60 percent of the world’s known oil resources, remains uncertain. Dependence on Persian Gulf oil is likely to grow over time given investment barriers around the world and the realities of the concentration of geologic resources in the Middle East. Indeed, the sudden loss of the Saudi oil network would paralyze the global economy in a manner that would be hard to counteract, given oil production capacity limitations in other countries. Energy resources will be vital to sustain worldwide economic growth, progress, peace, and security.
The rate of growth in energy demand worldwide runs the risk of outpacing affordable, clean supplies unless we can muster not only conservation and evolutionary improvements to existing technologies but also revolutionary new breakthroughs in the energy field and probably nanotechnology might provide an answer.
A seminar conducted by Rice University in the USA identified 13 energy nanotechnology challenges, a few which are listed below:
a) Photovoltaic Solar Energy – Lower cost by ten fold
b) Achieve commercial photocatalytic reduction of carbon – dioxide to methanol
c) Creation of a commercial process for direct photo conversion of light and water to produce hydrogen
d) Lower the cost of fuel cells by tenfold to a hundredfold and create new sturdier materials
e) Improve the efficiency/storage capacity of batteries and super-capacitors by tenfold to a hundredfold for automotive and distributed generation applications.
f) Create new, lightweight materials for hydrogen storage for pressure tanks and an easily reversible hydrogen chemisorption system.
g) Develop power cables, super conductors or quantum conductors made of new nanomaterials to rewire the electricity grid and enable long-distance, continental, and even international electrical energy transport, and reduce or eliminate thermal sag failures, eddy current losses, and resistive losses by replacing copper and aluminum wires.
h) Enable nanotechnology or nanoelectronics to revolutionize computers, sensors and devices for the electricity grid and other applications.
i) Develop thermo-chemical processes with catalysts to generate hydrogen from water at temperatures lower than 900 degrees Celsius and at commercial costs.
j) Create efficient lighting to replace incandescent and fluorescent lights.
The above were some of the points taken into consideration for developing cleaner methods of generation of power/electricity while providing a vital technological backup to the existing technologies including used in finding and recovering fossil fuels and technologies for storing and transmitting electricity. Electricity being a form of energy cannot be stored but scientists are thinking on terms of hydrogen. Hydrogen is not an energy source like coal, fossil fuels, oil, wind or the sun but it can be utilized as an energy carrier and can also be stored in large amounts. It can be converted into electricity or fuel through the use of a fuel cell or any other conversion technology and in that process providing cleaner power with fewer amounts of losses. But hydrogen is a long way ahead and lots of years before it can turn into reality.
Nanotechnology can be used to upgrade the existing systems in a lot of ways and is going impact energy in a lot of ways. As the demand for electricity increases, up gradation of existing transmission and distribution lines becomes a high priority. It is a well known fact that power transmission and distribution companies are using copper based lines for power transmission and distribution. These copper based lines lose about 7 percent of the power in transmission as is widely known.
With the usage of nanotechnology, carbon nanotube fiber bundles have the long term potential to be an ultra low loss, strong and lightweight replacement for the existing copper technology. With a current carrying capacity of 100 million amperes per square centimeter, such a bundle would have 100 times the capacity of the best low temperature superconductors. It will take time to develop a viable replacement however. The longest conducting nanotubes produced to date were announced this past October by researchers at UC Irvine—just 0.4 cm long (Refer Figure below).
Perhaps the broadest way in which nanotechnology will impact energy is on the consumption side. Lighting accounts for about 40 percent of all electricity consumption in the world. Researchers at Sandia believe that a new white LED technology, based on nanoscale manufacturing to create flawless devices, can cut that energy usage by half.
Other researchers are working with quantum dots to create color-selectable solid-state lighting for a variety of applications ranging from automotive and aircraft instrument displays to traffic lights and computer displays. By combining quantum dots of different sizes, the researchers hope to also be able to create white light.
Currently, researchers all over the world and in developed countries are using HTS power cables for transmission of power, which has been possible because of the intervention of nanotechnology. Uncle Sam has introduced this technology in many areas and can also be affected in other parts of the world. A small overview of the HTS cables would provide a better insight into the working and the advantages of using nanotechnology in power transmission and distribution.
A HTS (High Temperature Superconducting) power cable is a wire-based device that carries large amount of electrical current. There are two types of HTS cables and can be used according to the geographical locations. They are:
A) WARM DIELECTRIC CABLE
The warm dielectric cable configuration features a conductor made from HTS wires wound around a flexible hollow core (please refer figure 1). Liquid nitrogen flows through the core, cooling the HTS wire to the zero resistance state. The conductor is surrounded by conventional dielectric insulation. This kind of design is responsible for reducing power transmission losses to a large extent.
B) CRYOGENIC DIELECTRIC CABLE
This is another kind of dielectric cable that can be used to transmit power enduring the minimum amount of losses. It is but a coaxial configuration of an HTS conductor cooled by liquid nitrogen made to circulate within it. This is an enhancement/improvisation over the warm dielectric cable providing even greater ampere strength, reducing the losses even further and entirely eliminates the need for dielectric fluids (Please refer figure 2).
These kinds of cables ensure minimal technical losses during transmission and distribution and can be far more efficient than the existing copper lines used for transmission and distribution. Some of the advantages of utilizing these kinds of cables powered by nanotechnology are:
- Can meet increasing power demands in urban areas carrying two to five times more power than conventional cable
- Eliminates need to acquire new rights of way
- Replaces overhead transmission lines when environmental and other concerns prohibit their installation
- Enhanced overall system efficiency due to exceptionally low losses
- Increased utility system operating flexibility
- Reduced Electricity costs.
It has been seen that conventional underground power transmission cables are utilized to transmit huge amounts of power to all the more congested urban areas where overhead lines would be a problem. Conventional (copper-based) cables are capable of transmitting power (40 to 600 MVA) at high voltages (40 to 345 kV) while these cables can transmit higher capacities of electricity with minimal losses.
It is pertinent to mention here that superconducting cables can provide 2 to 5 times more power than conventional cables of the same size. No expensive and disruptive excavation and construction are required because the existing underground cables can be replaced with these kinds of HTS cables (Please refer Figure 3).
The question that looms large is that why India should go for HTS cables. India can gain from four distinct advantages that HTS cables provide over the existing copper ones:
a) Instant or Immediate Market Acceptance
b) Replacement of older cable systems past their rated life or with loads approaching the rating of the cable.
c) Replacement of existing overhead transmission and distribution lines with underground cables
d) Improvement/ Improvisation of conventional transmission and distribution service links from ‘Generation’ suppliers to ‘Open Access’ consumers (With GOI advocating for open access and as reiterated in Electricity Act of 2003).
Another promising feature of these HTS cables would be in High Power Distribution like those of 33/66 KV. Today, to increase a power supply to a particular urban area, utilities have to install transmission level voltage cables and utilize step-up (down) transformers at new substations. With stringent site requirements and the unfavorable view of new substations in urban areas, an HTS cable will be able to transmit the same amount of power at distribution level voltages and eliminate the need for new substations for that reason.
Nanotechnology necessarily involves cleaner methods of generation of power and its transmission and distribution also along with technological improvements to the existing technologies. For example, nanotechnology can be utilized in generation of solar power. Solar Photo Voltaic electricity production is the most obvious technology where nanostructured materials and nanotechnology are contributing to technology development. Currently, the world market for solar PV panels is about 400MW per year in 2001 (source: Photon International 9/2002, p 30, www.photon-magazine.com). Thin layers of nanostructured materials are used in the photo voltaic cells mounted on amorous silicon whose efficiency is lower than crystalline silicon.
Nanotechnology is not really difficult. Even a child can make organic solar cells including nanostructured material! A company Mansolar in the Netherlands manufactures and sells educational kits for school children to make their own organic solar cell, using blackcurrant juice or hibiscus tea as the dye. The company started in 2000 as a spin-off from the Energy Centre Netherlands ECN in Petten. (Please refer www.mansolar.nl).
As already discussed, earlier hydrogen is another consideration for storage of energy. There is a lot of discussion at the moment about the Hydrogen Economy in many seminars and forums, where hydrogen will be the dominant fuel, converted into electricity in fuel cells, leaving only water as waste product. The hydrogen is not freely available in nature in large quantities, so it must be produced by conversion of other energy sources, including fossil fuels and renewables. Only renewables based hydrogen production can contribute to CO2 emission reduction. Current renewable production methods of hydrogen include H2 production from biomass, from water by electrolysis (where the electricity has been produced by wind, solar or hydro energy). A company is based in Eatontown, New Jersey, USA since 1998, has a patented process in which a catalyzed reaction between water and sodium borohydrate produce hydrogen for applications in cars. The advantage is that the storage of the sodium borohydrate is inherently safe. It is a derivative of borax, which is a natural raw material with substantial natural reserves. (Please refer www.millenniumcell.com)
Nanotechnology can also contribute to the improvement of conventional energy sources including coal, oil, gas, and nuclear energy and electricity. To start with electricity, the production from coal or natural gas can be made more efficient by using nanotechnology in turbine plants. In nuclear energy, nanotechnology can help improve the radiation resistance of the materials.
There are many forms of primary energy, including fossil fuels such as oil and gas; biomass, nuclear energy, and renewables such as wind, sun, and hydro-energy. These primary energy sources must be transformed into heat, electricity or mechanical power (movement, pressure etc.). For some of these energy transformations, there is no efficient or cost effective solution. And for some of these needs for new energy transformation technologies, researchers are developing new nanostructured materials or nano-components. Fuel cells for transforming hydrogen or other gasses (natural gas, methanol) into electricity are a well-known example. But researchers are also working on less visible nanotechnologies such as catalysts and membranes for separating different types of gases. These can be used in fuel cells or other energy transforming technologies.
Greening Industrial Production
A lot of energy is applied in industrial production. This energy can be produced on site for instance by combined heat and power installations, or using the industrial waste as fuel. Industrial production can also contribute to energy saving by using less energy or materials for the same number of products or by making the products such as cars lighter, hence more energy efficient in their use.
The most sustainable energy use is no energy use. Governments all over the world and therefore in India also, stimulate energy saving by consumers as well as industry. Some of these measures imply the use of new technologies, such as improved isolation materials. Nanostructured materials such as nano-foams may play a role here.
Nanotechnology can contribute to solving future needs for energy technologies, especially in new generations of solar photo-voltaics, the hydrogen economy, more efficient conventional energy production and energy saving for industry as well as consumers. Considering the substantial budgets now-a-days governments all over the world allocating to nano-research including for energy applications, much of this potential is likely to be realized in the coming decades.
As again Mr. Darshan Goswami puts it, nanotechnology is being more utilized in the area of clean energy technologies but again it is evident and very much clear from the above that nanotechnology can also be utilized from strengthening the existing networks thus helping in improvising the standards of power transmission and distribution. This would therefore ensure higher amount of consumer satisfaction along with minimal losses and higher returns in the near future.
Journals & Research Papers
- Journal of Infrastructure Development, 2000, 2001 (Winter & Summer)
- Energy & Nanotechnology – Strategy for the Future published by Baker Institute Study (April 2005)
- Nanotechnology Research & Energy – Seminar paper (Journal of Infrastructure Development, 2004)