10 dec 2011
The new device has been described in a report in the journal Nanoscale Research Letters by Peter Bermel and other researchers at the Massachusetts Institute of Technology (MIT).
One of the traditional methods for harnessing solar energy involves use of the photovoltaic (PV) materials that capture sunlight and turn it into electricity.
The other solar thermal method uses an array of mirrors to focus and concentrate sunlight, enough to boil water and run a steam turbine for generating electricity.
A third less common approach is to use devices called thermophotovoltaics (TPV). These are solid-state devices that generate electricity directly from the heat emitted by the sun or any other radiant heat source such as combustible fuel.
The basic principle of their operation is similar to that of traditional photovoltaics with the difference that the radiant heat is absorbed directly not by the photovoltaic material but instead by a selective absorber in its top layer, causing it to emit light which is then converted to electricity by the photovoltaic cell.
For efficient operation of the TPV system, the material that absorbs and emits the heat radiation must operate at high temperatures, which means these solar TPV devices also require the use of mirrors to concentrate the sunlight to provide reasonable temperatures.
A cheaper, simpler way to tap solar energy
Scientists in the US have found a novel way to concentrate the sun's heat without using mirrors, potentially enabling a simpler and cheaper way to harness the solar energy using compact systems.
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| Dr Sanjay Kumar Cardiac Cardiothoracic Heart Surgeon India |
One of the traditional methods for harnessing solar energy involves use of the photovoltaic (PV) materials that capture sunlight and turn it into electricity.
The other solar thermal method uses an array of mirrors to focus and concentrate sunlight, enough to boil water and run a steam turbine for generating electricity.
A third less common approach is to use devices called thermophotovoltaics (TPV). These are solid-state devices that generate electricity directly from the heat emitted by the sun or any other radiant heat source such as combustible fuel.
The basic principle of their operation is similar to that of traditional photovoltaics with the difference that the radiant heat is absorbed directly not by the photovoltaic material but instead by a selective absorber in its top layer, causing it to emit light which is then converted to electricity by the photovoltaic cell.
For efficient operation of the TPV system, the material that absorbs and emits the heat radiation must operate at high temperatures, which means these solar TPV devices also require the use of mirrors to concentrate the sunlight to provide reasonable temperatures.
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