This sounds great, but for some years we hear of various discoveries that will greatly increase solar panel efficiency. Why are we still at 22%-ish?
Rice University researchers propose a way to boost solar efficiency
81–90 of 127 posts
Re: Rice University researchers propose a way to boost solar efficiency
#82Earlier quoted context omitted.
I am especially infuriated by how it repeats a common misconception of infrared light as the epitome of "heat", as if it was some kind of separate particle.
What is the accurate model of infrared light vs. heat?
All physical objects emit electromagnetic radiation corresponding to their temperature (as opposed to reflected, reaction-induced, or stimulated radiation, more below), with a corresponding blackbody radiation curve. Note that blackbody emissions don't have a specific frequency (say, unlike laser light), though the curve has a peak emission.
Traditional incandescent light bulbs are blackbody emitters, as is a hot coal, the Sun and other stars, or the glowing elements of an electric radiant heater. Human eyes see blackbody radiation, in the visible range, as having a characteristic colour, which paradoxically gets bluer as the temperature gets higher, so the ruddy tones of low-voltage incandescent lamps are low colour temperature, and the intense white of halogen lamps are high colour temperatures. Blackbody radiation and colour temperatures are given in Kelvin, with typical visible light corresponding roughly to ~3,000 - 8,000K. You might also recognise these values from gamma or colour correction values on monitors and video equipment.
(Colour temperatures were used to judge processing for ceramics and metal processing / firing / smelting processes as well. They're also used to classify stellar temperatures, and in conjunction with brightness and/or distance estimates can be used to find stellar sizes.)
Infrared light is characteristic of peak blackbody emissions of bodies at or near "room temperature". So IR is not heat, but is associated with hot objects. Heat itself is ... thermal energy, which is its own complex thing.
Since all EMR carries energy, all EMR heats objects in which it is absorbed. A sufficiently intense emission above the IR range will also heat an object. However hot objects in near proximity transfer a great deal of thermal energy directly as IR emissions. The illuminating capability of "white" light (typical solar emissions) allows a small amout of EMR energy to provide a high degree of visual information without imparting much heat on the illuminated objects (though it does impart some). Consider that even an (inefficient) 100W incandescent bulb, whilst hot to the touch, does not significantly heat the objects it is illuminating, and a far more efficient equivalent LED lamp, drawing about 15W of electrical power, accomplishes the same illuminating power with vastly less heat. We don't have to toast things to be able to see them, just bounce a small amount of (high-energy) visible light off of them.
Not all light (or more accurately, EMR) is blackbody radiation. There can be chemically-emitted light, directly from chemical reactions. The blue glow of methane (natural gas) combustion is a chemical emission, contrasted with the yellow-white glow of a candle, actually blackbody emissions of suspended soot particles in the smoke plume. (There's a blue region of chemical emission at the base of the flame.)
Chemical emissions are based on specific frequencies of EMR emitted as electrons transition between energy states, if I understand correctly are a quantum phenomenon. Fluourescent and LED lamps also work based on chemical / valance emissions, and operate in far narrower bands than blackbody emissions -- one of the reasons these lamps can appear harsher than incandescents. Similarly various chemical lamps, especially high- or low-pressure sodium vapour, formerly popular as street lighting, which emit in narrow bands (low-pressure especially).
Some forms of ionizing radiation are also EMR emissions, at far higher energy levels, triggered by nuclear rather than electron emissions. Typically gamma-rays.
And stimulated emissions such as lasers and masers are ... another phenomenon I understand only poorly, but are also tuned to very tight frequencies. Radio and microwave emitters are somewhat similar.
https://en.wikipedia.org/wiki/Black-body_radiation
Re: Rice University researchers propose a way to boost solar efficiency
#83This is what we need before we're all fucked.
Re: Rice University researchers propose a way to boost solar efficiency
#84Earlier quoted context omitted.
Oh, it's definitely amazing relative to where it was, just not to where it needs to be to compete. Solar and wind is less than 1% of world energy consumption and is not expected to be more than 3-4% in 2040. Energy is not a product/market problem it's a physics problem and we haven't had any major breakthroughs in that space for a long long time. https://www.iea.org/weo/?fbclid=IwAR3eH1AFcRSPSEit8JINLCMvE_...
This... doesn't have to be the case. Some markets already have way higher renewable penetration. Solar and wind represented about 20% of all generation in California in 2018 ( https://ww2.energy.ca.gov/almanac/electricity_data/total_sys... ). In the UK this year, solar and wind are almost 25% of generated electricity ( https://assets.publishing.service.gov.uk/government/uploads/... ) Incremental improvement and econo…
http://www.ercot.com/content/wcm/lists/181766/IntGenbyFuel20...
The state produces by far the most electricity of any state, too. It's almost twice as much as Florida.
https://www.eia.gov/state/?sid=TX
Unfortunately it's also a huge petroleum and natural gas producer. About half of the energy used in the state is for industrial use, much of it for the oil and gas industries. On the bright side, natural gas is displacing coal in the meantime while solar and wind are not replacing it fast enough. It needs to get better, but things could be much worse.
Re: Rice University researchers propose a way to boost solar efficiency
#85The title is misleading. The full title is: > Researchers at Rice University developed a method to convert heat into light that could boost solar efficiency from 22% to 80% The conditional tense signals that the researchers didn't actually do so, but that the study might enable it. The article re-iterates that this is speculation: > The implications of their discovery are significant. Research from Chloe Doiron, a Ri…
Maybe speculation should not be presented as a statement of fact in the title.
Re: Rice University researchers propose a way to boost solar efficiency
#86I get the maybes and the caveats, the misleading title but the direction seems clear - solar efficiency is a tractable materials science problem - and "we" should see this as a penicillin moment - invest hugely into the research and development until we find the right processes and approach to make cheap ubiquitous solar. Manhattan project levels of finding is what I mean - because the pay off is humans cutting their…
Research and speculation is awesome stuff, but the hard part isn't discovering new concepts. It is actually making those concepts into a marketable and affordable good.
The evidence for this is that even though there is essentially a new 'breakthrough' discovery every other week for solar panels, or electric motors, or batteries.. We are still using what amounts to cutting-edge tech from the late 90's.
In the modern era this means we generally have to wait till the patents expire and market competition kicks in in order to get the price low enough and the product perfected enough to see widespread usage. If it goes anywhere at all.
It's also worth noting that Florey, the man who is largely responsible in making penicillin practical drug, refused to patent his early innovations to make it widespread as possible.
Re: Rice University researchers propose a way to boost solar efficiency
#87Re: Rice University researchers propose a way to boost solar efficiency
#88Earlier quoted context omitted.
Sorry for a potentially stupid question: why do they need to convert heat into visible light? Why can't we convert heat directly into electricity at the same time as we convert visible light into electricity?
You're confused – heat isn't being converted into anything. The article conflates the words "heat" and "infrared radiation", which are not at all the same thing. As a rule, everything around you glows – in other words, it emits photons. Some infrared ones, some visible ones, some ultraviolet (or even higher-frequency) ones. How much of each depends on the temperature of the material. Most things (e.g. you) are too co…
Once a solar cell is built with this technology, do you think there will be enough light emitted by the nanotubes to make the solar panels appear to glow, themselves? Because that would be pretty interesting.
Re: Rice University researchers propose a way to boost solar efficiency
#89Earlier quoted context omitted.
Sure it is. Lower efficiency means you need more panels, larger panels, and more support infrastructure. It limits where it can be deployed and makes it less competitive.
And the need for more/larger panels and support structures will only be a win if overall, the costs decrease. The cost is what makes the decision for deployment, not the efficiency. Perhaps this efficiency makes 2-axis tracking economical enough to justify, and then it gets deployed, but in the end the efficiency wasn't as important as the improved costs.
Re: Rice University researchers propose a way to boost solar efficiency
#90I get the maybes and the caveats, the misleading title but the direction seems clear - solar efficiency is a tractable materials science problem - and "we" should see this as a penicillin moment - invest hugely into the research and development until we find the right processes and approach to make cheap ubiquitous solar. Manhattan project levels of finding is what I mean - because the pay off is humans cutting their…