# Tag Info

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This is mainly an engineering & economics question; and we can deal with those aspects of it over on the Sustainability Stack Exchange, if you want. And there is one conceptual physics aspect too. No, fresnel lenses are not widely used for solar power. Occasionally, but rarely. Concentrated solar power (CSP), including concentrated photovoltiacs (CPV) ...

4

Fresnel lenses are not used, but fresnel reflectors may be soon. There are two main ways in which electricity is generated from sunlight: Photovoltaics: These (what are commonly thought of as "solar panels") are generally used without optics. The reason is that they will accept light from nearly any direction, and the power generated is directly ...

3

Boden & Bagnall (pdf) looked at this question of reflection, in their paper Bio-Mimetic Subwavelength Surfaces for Near-Zero Reflection Sunrise to Sunset. Their estimate of the proportion of photons reflected, from sunrise to sunset, in a fixed PV system is 20%, rather than your estimate of one-third. The proposed etalon is not an efficient or ...

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Short answer: On something operating with non-coherent light on the scale of a solar power collector, there is no net effect from interference. The increase in light intensity is not additive interference at all, but is simply that the light falling on a wide area is collected and focussed on a small area. However, I'm guessing that there is some confusion ...

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Let's suppose the light from the Sun was perfectly coherent. In that case you would get interference, however the optics used in the sort of solar tower you show are manufactured to nowhere near single wavelength of light precision. That means the phase of the light arriving at the collector would vary wildly with position across the collector, and the ...

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Ballpark estimate, I'm not a geoscientist so I don't kn ow if the whole idea even makes sense: This abstract of a paywalled articel states $4*10^{10} W$ Energy release and a mass flux of $3 * 10^4 kg s^{-1}$. So we are talking roundabout $1.3*10^6 J kg^{-1}$. A supervolcano eruption is typically defined as yielding more than $450 km^3$ magma. Assuming a ...

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Though it is not common to use Fresnel lenses for electricity generation but 100 MW power plant is nearing completion in Rajasthan state of India using linear Fresnel lens technology. So to say that this technology is not feasible for large scale use is not correct and time may come if that above mentioned power generation goes smoothly, the scene may change ...

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The basic energy requirements of homes, industries etc are measured in watts. It may be sometimes seen how much energy each sector utilizes over a span of time, but generally we see how many watts are used in homes, industries then further in colonies, cities etc. Atleast here in India (and I think it would be similar everywhere) we get our home supplies ...

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Some PV modules are indeed one single large area: thin-film modules and polycrystalline silicon modules can be done as one single large area, or as arrays of rectangular cells. The design in this case is driven by economics. Monorystalline silicon modules always consist of an array of connected cells: and the reason for that is primarily about the science, ...

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First off, I would be cautious about interpreting the parameter that press releases focus on as being the "most important" - it's just as likely to be the one that a press officer happened to pick because it seemed like a Nice Big Number, or possibly the one that they understood. Think yourself lucky if the units actually made sense! However, there is a ...

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Light gets "trapped" in an optical fiber when the light travels such that the angle of incidence when hitting the surface is low enough that the optical index change causes the light to "bend" back into the fiber. This is known as total internal reflection. Basically with larger fibers you'll get light bleeding out. Thin fibers work over long distance ...

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Let's look at the amount of energy (in Joules) in one second - i.e. in SI units of power, Watts: that way, you can directly compare between them, and scale up the times as you choose. So, for Wh, kWh, MWh, etc - it's each of the activities below, for one hour 2 W average power used in charging a mobile (cell) phone 20 W laptop power consumption, at low ...

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Contrary to what we might want to believe, any kind of perpetual motion device would violate the known laws of physics. No system can create energy out of nothing, and even if an engine were 100% efficient and didn't lose anything to friction, gravity, etc, it might run forever as long as there was no draw of energy out (ie. to do useful work). As nice as it ...

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I think the point you are making is why isn't the n-CdS/p-CdTe junction inverted to be p-CdTe/n-CdS. As you say this would allow the "high mobility" CdTe layer (it's not really high mobility, it more that any carriers generated in CdS recombine instantly) to be placed first and absorb a little extra light. Something on the order of $7mA/cm^2$ of photocurrent ...

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A typical bifacial module will transmit energy that passes through the silicon as well as the energy that passes around the edges of the cells which would otherwise be absorbed in a typical monofacial module design, around 3% of the total. Using the 20% energy transmission value quoted above, a bifacial solar module will absorb ~23% less energy than a ...

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There are many ideas analogous to the water tower/turbine/pump system (minus the solar panels). One common example is a water electrolysis system which passes an electric current through water to split water molecules into hydrogen and oxygen, which is then used as a fuel in either an engine or fuel cell to produce electric power to feed the electrolysis ...

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