Introduction to Nanotechnology for Energy:
The production and use of oil and other fossil fuels continues to rise on a yearly basis to record new levels. At the same time, fewer new oil fields are being identified which means that sometime over the next few decades oil production will not be able to satisfy demand.
Not only are we running out of oil, but our use of fossil fuels is putting an increasing burden on the environment in terms of greenhouse gases and global warming.
Alternative energy sources are known, but their efficiency based on cost is poor. Nanotechnology advances can improve this.
Nanotechnology for Energy - Insulation:
Humankind has used natural materials for insulation throughout its history. While traditional materials work well in settings where bulk application is possible, such as wall cavities, they are not suitable for applications such as glazing where significant amounts of heat can be lost or gained.
Nanotechnology offers enhanced insulation allowing thinner coatings or fillings to prevent heat loss or gain which would not be possible with conventional materials.
Nansulate is a patented nanotechnology coating which blocks heat transfer and reduced energy use.
Nanotechnology for Energy - Solar :
The efficiency of a solar cell depends on how much of the available spectrum of light it can absorb (the rest is simply reflected or lost as heat), and how effectively it converts this energy into electricity.
The problems with current methods are the expense of material and relatively low efficiency. This means that solar energy is several times more expensive than energy derived from burning fossil fuels.
New nanomaterials have a higher efficiency than silicon used in existing solar panels. Nanotechnology can also offer new applications such as flexible panels.
Nanotechnology for Energy - Hydrogen :
Most of our energy needs are met by combustion - of coal, gas and oil. However this is not the most efficient way to extract energy from fuels. Fuel cells do so chemically by reacting hydrogen and oxygen gases together to make water, heat and electrical charge. The mechanism of generating energy varies between fuel cells, however in each case a charged ion (which is usually hydrogen or oxygen), is produced at one electrode and migrates to the other through a selectively permeable membrane, while the electrons produced as a result of this travel through an external circuit, powering devices.
Fuel cells fall into two groups: those with a high operating temperature (above 200°C) which are suitable for supplying power to whole buildings (such as solid oxide and molten carbonate fuel cells) and lower temperature units which are suitable for powering vehicles and mobile devices (such as direct methanol and polymer exchange membrane fuel cells). The high temperature units can use natural gas to form hydrogen, the lower temperature units, with the exception of direct methanol fuel cells, require hydrogen gas itself.
Hydrogen at the moment is largely produced from natural gas, however in the future it is hoped that renewable energy could be used to supply the necessary power to split (electrolyse) water into hydrogen and oxygen (i.e. the reverse of the reaction in a fuel cell).
Nanotechnology can offer solutions to material costs, fuel cell efficiency, and storage of hydrogen feedstock.
Nanotechnology for Energy - Thermoelectricity :
Thermoelectricity is the conversion of heat to electricity and vice versa. It relies on connecting two different electrically conducting materials, which conduct heat at different rates, at two junctions (thermocouples) in a closed loop. Applying heat at one thermocouple while keeping the other cool generates an electric current within the loop. Combining many such loops produces a thermopile which can be used to power devices e.g. radios and clocks. In contrast, if electricity is passed through the loop then the thermocouples will heat or cool (which can be used for heaters or fridges). Both metals and semiconductors can be used to generate this effect.
Thermoelectric generators have advantages over those using conventional materials as they have a smaller size, and no mechanical parts that can fail or deteriorate over time.
Nanotechnology for Energy - Portable Power :
Portable devices are commonplace in modern society, from consumer products such as mobile phones and MP3 players, to medical diagnostic equipment, to environmental and chemical sensor equipment. In all cases increased functionality, smaller size and longer operating times are desired. This can include improvements to existing systems such as rechargeable batteries to supply more power and energy. It can also include new technologies such as fuel cells which generate electricity from hydrogen .
Increases in the energy and power output of portable supplies can not only affect portable devices, but at the other end of the scale could offer breakthroughs for all-electric vehicles, for off-grid power systems and for high-technology applications such as aeronautics. The global battery market is worth some 30 billion USD and is increasing dramatically.
New battery technologies from MIT.
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