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Rice University researchers propose a way to boost solar efficiency

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Re: Rice University researchers propose a way to boost solar efficiency

#31

Post by anchpop »

ThomPete wrote: post #23
blunte wrote: post #21

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?

The primary issue with everything in this category is that plenty of things are possible in the lab or in theory which just isn't possible when applied in reality and at scale. Blame journalists for hyping this because of the climate change focus. I am involved in actively looking for better materials and better sources of energy. The reality is that there are no fundamental breakthroughs since oil and nuclear. No ma…

Why do you consider cheap solar not a breakthrough? If I 30-year mortgaged some solar cells, I could put them on my house right now and save $20 a month on net because of reduced electricity costs

Re: Rice University researchers propose a way to boost solar efficiency

#32

Post by amluto »

As far as I can tell, this is functionally just a coating with low emittance in the IR outside a narrow band. A matched PV device that is kept cool can, in principle, approach the Carnot efficiency for the temperature difference between the emitter and the PV junction. If the emitter is the sun, then the source temperature is very high and the Carnot efficiency isn’t a major limit. If the source is a solar panel, I’m having a hard time seeing how this is useful.

I can see this being somewhat useful as a no-moving-parts heat engine for something like a solar concentrator, but there’s another relevant thermodynamic limit: even if this magic material has emissivity 1, it won’t radiate at a greater power per unit area than the blackbody spectrum predicts. At non-crazy temperatures, this is not very high, which will limit output for small things like solar concentrator targets.

So I can see this being useful to convert waste industrial heat, or maybe as a bottoming engine for a combined cycle plant, but I am having trouble understanding how it could be useful for solar.

Re: Rice University researchers propose a way to boost solar efficiency

#35

Post by ryanmarsh »

xendo wrote: post #27

I wonder if the process of changing heat into light can be used for transferring heat more efficiently than current AC units.

This has been discussed in several previous threads on HN. From what I’ve been able to gather, creative ways to reduce the energy consumption of A/C will require a change to building designs, and/or increase the cost and complexity of new buildings. Whereas the cost of running the A/C is up to the future tenant(s).

This is why you see some companies applying eco friendly tech to some new buildings (Apple) but not in general commercial development.

Again this is just what I’ve surmised from reading threads like this. YMMV

Re: Rice University researchers propose a way to boost solar efficiency

#36

Post by ryanmarsh »

i_am_nomad wrote: post #25

Interesting work - seems like this could also be used to create a thin film that could yield thermal vision, if indeed the nanotubes upshift IR frequencies to visible light. But I’m not a physicist.

This is essentially the same principle behind current night vision tech.

Re: Rice University researchers propose a way to boost solar efficiency

#37

Post by 9588 »

ThomPete wrote: post #23
blunte wrote: post #21

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?

The primary issue with everything in this category is that plenty of things are possible in the lab or in theory which just isn't possible when applied in reality and at scale. Blame journalists for hyping this because of the climate change focus. I am involved in actively looking for better materials and better sources of energy. The reality is that there are no fundamental breakthroughs since oil and nuclear. No ma…

5000 classified patents per year in the US alone. No one else publishes a number.

Modest estimate would be 200 000 over the last 30-40 years.

Some of it must relate to energy.

Re: Rice University researchers propose a way to boost solar efficiency

#38

Post by mikepurvis »

ryanmarsh wrote: post #35
xendo wrote: post #27

I wonder if the process of changing heat into light can be used for transferring heat more efficiently than current AC units.

This has been discussed in several previous threads on HN. From what I’ve been able to gather, creative ways to reduce the energy consumption of A/C will require a change to building designs, and/or increase the cost and complexity of new buildings. Whereas the cost of running the A/C is up to the future tenant(s). This is why you see some companies applying eco friendly tech to some new buildings (Apple) but not in…

Interesting to contemplate what could be done to shift those incentives around. Obviously there are certifications (LEED), and there's straight-up regulation, but would there be a way to mandate that a builder or landlord is responsible for a portion of future HVAC expenses such that they are motivated to get this right upfront?

Re: Rice University researchers propose a way to boost solar efficiency

#39

Post by dman »

blunte wrote: post #21

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?

Because everyone reports relative gains in these articles and not absolute efficiency.

Re: Rice University researchers propose a way to boost solar efficiency

#40

Post by philipkglass »

ThomPete wrote: post #23
blunte wrote: post #21

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?

The primary issue with everything in this category is that plenty of things are possible in the lab or in theory which just isn't possible when applied in reality and at scale. Blame journalists for hyping this because of the climate change focus. I am involved in actively looking for better materials and better sources of energy. The reality is that there are no fundamental breakthroughs since oil and nuclear. No ma…

Fuel cells have been commercially available since the 1960s, though they were mostly confined to space program applications then.

Automobile manufacturers have produced small numbers of fuel cell vehicles since the turn of the millennium:

https://en.wikipedia.org/wiki/Fuel_cell_vehicle#List_of_mode...

I'm not making claims about the actual merits of fuel cells, mind you. But claiming they're further out than fusion is bizarre. Some people are driving them around today. Nobody is generating net power from fusion today.

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