diy solar

diy solar

New, more efficient solar panels coming? Hopefully.

Sennen

Sennen

Solar Enthusiast
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They seem to think it will be much cheaper to produce than current panels, too.

www.nature.com

High-performance bifacial perovskite solar cells enabled by single-walled carbon nanotubes - Nature Communications

The suboptimal optical transmittance of back electrodes and complex fabrication process hindered development of bifacial perovskite solar cells. Here, authors apply single-walled carbon nanotubes as front and back electrodes, achieving power generation density of 36% and bifaciality factor of 98%.
www.nature.com www.nature.com

en.shiftdelete.net

Solar panels becoming obsolete! A 70% cheaper alternative is coming

A new type of solar panel alternative with carbon nanotubes and dual-sided features offers 97% efficiency in solar energy technology.
en.shiftdelete.net en.shiftdelete.net
 
Lower price doesn't matter much anymore because we're buying PV panels for $0.20/W in the US (think they're $0.10/W in China).
Cost is beginning to be dominated by mounting hardware. And it is eclipsed by labor.

More efficient so less area, less mounting hardware, less labor would be a savings.
But only if not more cost per watt. And just as durable, so we don't have to pay for installation twice as often.

Labor, permits, etc. are the majority of cost today, like 2/3 of total for residential at least.
We pay $3/W for rooftop GT PV, with parts being about $1/W or less.

Compare to Australia, $1/W turnkey installed.

There are some initiatives to streamline permitting.

diysolarforum.com

SolarApp+

SolarApp+ From https://solarapp.nrel.gov/: Safe and affordable home solar through permitting automation In 2021, the National Renewable Energy Laboratory launched a collaborative effort with key code officials, authorities having jurisdiction, and the solar industry to develop standardized plan...
diysolarforum.com diysolarforum.com
 
Certainly not against higher performance panels, and lower cost is always welcome.

Last batch from Signature were $0.30 / watt, so I've got no complaints.
 
Heck I can buy panels on Ebay that must be more efficient than 36% based on size now. Not sure how they do it but 400w from 11in. by 11in panel. For the low price of $49! That would be just a bit more than a penny a watt not including the free controller and accessories.

No need to wait.
 

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Mattb4 said:
Heck I can buy panels on Ebay that must be more efficient than 36% based on size now. Not sure how they do it but 400w from 11in. by 11in panel. For the low price of $49! That would be just a bit more than a penny a watt not including the free controller and accessories.

No need to wait.
Click to expand...
I don’t believe the ad is accurate. I’ve seen ads like this that claim a high wattage that doesn’t ad up with the voltage and current specs. If you could get a 400 watt panel in an 11 inch square panel for $49 that would be amazing and also huge news 😎
 
Hedges said:
Lower price doesn't matter much anymore because we're buying PV panels for $0.20/W in the US (think they're $0.10/W in China).
Cost is beginning to be dominated by mounting hardware. And it is eclipsed by labor.

More efficient so less area, less mounting hardware, less labor would be a savings.
But only if not more cost per watt. And just as durable, so we don't have to pay for installation twice as often.

Labor, permits, etc. are the majority of cost today, like 2/3 of total for residential at least.
We pay $3/W for rooftop GT PV, with parts being about $1/W or less.

Compare to Australia, $1/W turnkey installed.

There are some initiatives to streamline permitting.

diysolarforum.com

SolarApp+

SolarApp+ From https://solarapp.nrel.gov/: Safe and affordable home solar through permitting automation In 2021, the National Renewable Energy Laboratory launched a collaborative effort with key code officials, authorities having jurisdiction, and the solar industry to develop standardized plan...
diysolarforum.com diysolarforum.com
Click to expand...
AZ Solar Junkie said:
I don’t believe the ad is accurate. I’ve seen ads like this that claim a high wattage that doesn’t ad up with the voltage and current specs. If you could get a 400 watt panel in an 11 inch square panel for $49 that would be amazing and also huge news 😎
Click to expand...
You could of course construct a stacked solar 'cell' comprised of say 2 layers of perovskite/sillicon PV mounted onto a 'polished nickel substrate reflector'. Assuming the layers have 20% conversion efficiency each then total conversion efficiency would be a little under 60%. (20 + 16 + 12.8 + 10.2). so a 1.8m x 1.2m panel would give about 1200W (compared to current 400W for same size) figures are approximate. Cost would be about 20% more for 200% more power. An added benefit is that the heating due to thermal effect would be reduced by 40 to 50% so the panels would run cooler resulting in lower efficiency loss over time and increased lifetime.... That's Win, Win, Win, Win imho.....

More than 2 layers give diminishing returns so more than 3 or 4 layers is of no economic value.

Oh, i almost forget adding a fresnel lens to the top layer, helps capture more of the incident light and reduces the emitted (reflected) light increasing the efficiency by a further 8%....
 
Last edited:
MrFuzion said:
You could of course construct a stacked solar 'cell' comprised of say 2 layers of perovskite/sillicon PV mounted onto a 'polished nickel substrate reflector'. Assuming the layers have 20% conversion efficiency each then total conversion efficiency would be a little under 60%. (20 + 16 + 12.8 + 10.2). so a 1.8m x 1.2m panel would give about 1200W (compared to current 400W for same size) figures are approximate. Cost would be about 20% more for 200% more power.
Click to expand...

Are you sure about 20% more cost?

One P/N diode junction in single-crystal cells is sliced silicon ingots with implant baked in. Assembled panels are about $0.10/W in China, $40 for 400W?
Two layers means thin-film processing on top, vacuum deposition. At what cost? About the price of a flat-screen TV glass?
 
Hedges said:
Are you sure about 20% more cost?

One P/N diode junction in single-crystal cells is sliced silicon ingots with implant baked in. Assembled panels are about $0.10/W in China, $40 for 400W?
Two layers means thin-film processing on top, vacuum deposition. At what cost? About the price of a flat-screen TV glass?
Click to expand...
What % of the Assembled panel cost is down to the cost of the silicon PV segment when you factor in the Assembly , Test, Shipping, Taxes, Profit margin, etc...

So what you do is take a single cell and stack another on top, (chip on chip has already been done), In this case there is no need for the back metal on the top slice (just grind and polish), but the bottom slice should have a top solderable metal (already in use in some FABs). You bond the two slices together either by ultrasonic or thermal welding (basically melt the top metal of the bottom slice), again this is an existing die attach process (nothing new here).

Furthermore, you can use a thinner slice from your ingot (equals more slices)

Now build your panels using the stacked cells....(the process is the same)...

The geometries are very large so no critical alignment issues.

Also the top of a solar panel is a sheet of protective glass (just like your TV panel.
 
Last edited:
MrFuzion said:
What % of the Assembled panel cost is down to the cost of the silicon PV segment when you factor in the Assembly , Test, Shipping, Taxes, Profit margin, etc...

So what you do is take a single cell and stack another on top, (chip on chip has already been done), In this case there is no need for the back metal on the top slice (just grind and polish), but the bottom slice should have a top solderable metal (already in use in some FABs). You bond the two slices together either by ultrasonic or thermal welding (basically melt the top metal of the bottom slice), again this is an existing die attach process (nothing new here).

Furthermore, you can use a thinner slice from your ingot (equals more slices)

Now build your panels using the stacked cells....(the process is the same)...

The geometries are very large so no critical alignment issues.

Also the top of a solar panel is a sheet of protective glass (just like your TV panel.
Click to expand...
Sounds interesting, though outside of my expertise. My question though is if this idea is feasible, why aren’t they manufacturing panels like this?
 
AZ Solar Junkie said:
Sounds interesting, though outside of my expertise. My question though is if this idea is feasible, why aren’t they manufacturing panels like this?
Click to expand...
You mean perovskites?

Cost; they are far more expensive than single crystal silicon.
Efficiency; they are not that much more efficient. Good pervoskites can hit 25% these days, but single crystal silicon can hit 23.5%.
Manufacturability. No one has manufactures perovskites in large quantities yet,
 
Mattb4 said:
Heck I can buy panels on Ebay that must be more efficient than 36% based on size now. Not sure how they do it but 400w from 11in. by 11in panel. For the low price of $49! That would be just a bit more than a penny a watt not including the free controller and accessories.

No need to wait.
Click to expand...
Well shucks , based on these panels size and power , I could get approx 120,000 watts of PV power on my RV roof….I missed that boat…story of my life…
 
Agreed Perovskites are more costly, than Silicon PV, but my calculation was based on a layer efficiency of 20%

Top Layer 20% (of the incident 100%) = 20%
Bottom Layer 20% (of remaining 80%) = 16%
Reflect back
Bottom Layer 20% (of remaining 64%) = 12.8%
Top Layer 20% (of remaining 51.2%) = 10.24%
Total conversion (Assuming no other losses) = 59.04%

I do expect there to be some losses in the reflection and transmission steps, but this is offset by the present efficiencies (>23%).

Also there are some simple techniques (nothing new) that could be used easily and cheaply to increase the efficiency further.

A couple more things that are in development...

Reel to Reel 'printing' of PV on polymer 'like newsprint', although not currently as efficient as existing PV, it is only a fraction of the cost.

Transparent PV on Polymer windows, (again not as efficient, but potentially useful on High Rise office blocks.
 
AZ Solar Junkie said:
Sounds interesting, though outside of my expertise. My question though is if this idea is feasible, why aren’t they manufacturing panels like this?
Click to expand...
Why have they only just started making bifacial panels in volume ?,
Why have then combined PhotoElectric and ThermoElectric effects in the PV Panels.... (Solar & Thermal) ?

My Guess is its commercial thing, "Profit Margin 'v' Competitive Advantage 'v' Market Forces, 'v' Demand".
 
MrFuzion said:
Why have they only just started making bifacial panels in volume ?,
Why have then combined PhotoElectric and ThermoElectric effects in the PV Panels.... (Solar & Thermal) ?

My Guess is its commercial thing, "Profit Margin 'v' Competitive Advantage 'v' Market Forces, 'v' Demand".
Click to expand...
Yup, slow roll out to make everyone buy everything twice. :)
 
MrFuzion said:
Agreed Perovskites are more costly, than Silicon PV, but my calculation was based on a layer efficiency of 20%

Top Layer 20% (of the incident 100%) = 20%
Bottom Layer 20% (of remaining 80%) = 16%
Reflect back
Bottom Layer 20% (of remaining 64%) = 12.8%
Top Layer 20% (of remaining 51.2%) = 10.24%
Total conversion (Assuming no other losses) = 59.04%
Click to expand...
They don't add like that. A 20% efficient cell doesn't transmit the other 80% as usable light energy. In tandem cells (like perovskite + silicon) you lose most of the energy when it goes through the transparent cell, so your gain gets smaller and smaller. Keep in mind that the most efficient three-junction cells on the planet only get to 39% - and they are tens of thousands of dollars per watt, usable only for spacecraft and the like.
 
MrFuzion said:
Why have they only just started making bifacial panels in volume ?,
Why have then combined PhotoElectric and ThermoElectric effects in the PV Panels.... (Solar & Thermal) ?
Click to expand...
They've been making bifacial panels in volume for at least five years now.

Combined thermo and photovoltaic panels don't work well. To get a thermovolatic cell to work you need high temperatures on one side and low temperatures on the other. So not only do you need active cooling of the back, you have to run the front hotter, and silicon PV cells don't work well at high temperatures.
 
billvon said:
They don't add like that. A 20% efficient cell doesn't transmit the other 80% as usable light energy. In tandem cells (like perovskite + silicon) you lose most of the energy when it goes through the transparent cell, so your gain gets smaller and smaller. Keep in mind that the most efficient three-junction cells on the planet only get to 39% - and they are tens of thousands of dollars per watt, usable only for spacecraft and the like.
Click to expand...
I agree there are some losses but the laws of thermodynamics and conservation of energy still apply so, if 20% of the photons are converted into electrons in the first layer, the other 80%(ish) are transmitted to the next layer down (because they cant just disappear). The fundamental problem with solar panels is they get very hot because the majority of the photons are absorbed in the black bottom layer which is neither photoelectric or thermoelectric. Extracting more of the energy as electrons will inherently reduce the operating temperature and there may be other technologies that haven't been considered as a means of doing this. As i said previously reflecting the transmitted light so it passes through the layers twice should double (almost) the conversion rate, indeed a bifacial panel is basically this but with a non transparent interstitial layer.
 
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