Theoretical maximum output from panels

[mike788]

Hello everyone,

So, I'm a newbie on here and wanted to get your expert feedback on this conversation.

I've looked at previous posts from years ago on this forum, and so now want to pose the question again.

With the advent in solar technology in Poly, Mono and now PERC and output figures rising all the time, what does everyone feel is now the theoretical maximum output from, let's say a panel sized 1650mmx1000mm using either 5",6",7" or half cell designs?

My old panels in the back garden are this size and rated at 265w, but technology has moved on.

Obviously there are newer designs out there, but the sizes of these new panels seem to be getting rather large.

With the standard formula of 1000w/sqm input to panels (STC), what are the possibilities of creating a 1650mmx1000mm single panel that could deliver close to 1kW output?

Really interested to hear your thoughts.

[J.P.M.]

It's probably better to think of efficiencies in terms of percentages rather than the max. output of a particular sized panel.

At this time and in spite of all the hoopla about super duper revolutionary discoveries and techniques which are still mostly the stuff of white collar welfare master's and doctoral theses, vaporware and wishful thinking, the highest published STC efficiency for a silicon based PV panel is a bit under 23 % and has stayed there for several years. Conmen and shysters claim more but the reality is that at this time, here isn't much new and in production under the sun.

For silicon based cells, the cutoff wavelength for useful energy is about 1.13 to 1.15 microns. Wavelengths longer than that which constitute about 26 % or so of the energy contained in incoming sea level irradiance is unusable and only serves to heat the cell.
In addition to that cutoff loss, each photon causes the creation of a single hole-electron pair, and the energy in excess of that required to create hole-electron pairs is also converted to heat. From these considerations alone, the max. theoretical efficiency of silicon based cells is something like 23 or so % under STC conditions.

There will most likely be improvements that increase cell efficiencies above that 23 % STC efficiency but they will probably be incremental and not too be great.
For the foreseeable future more value is likely to be obtained in improved production methods.

To your question, for a 1.65m^2 PV panel using the latest in-production technology to have an STC output of 1kW with an input of 1kW/m^2 would require it to have an STC efficiency of (output/input) = (1kW/1.65m^2)/(1kW/(1)m^2) = 0.606.
Given where we are at this time, looks to me like the efficiency glass is a lot less than half full. I'm not real optimistic about pushing entropy uphill that far with the now available tools, at least not any time soon.

[littleharbor2]

So at 1.65 meter squared and 23% efficiency you would not ever see more than 379.5 watts. Problem is that 1,65 sq. meter panel isn't 100% covered with silicon cells. There are gaps between cells, bus bars on the cell surface, dirt and bird droppings, etc. preventing max output. They are getting pretty close though. Here's a 60 cell panel's specs. Although it is slightly larger than the theoretical panel in this thread it is putting out surprising wattage for it's size.

LG-370N1K-A6 Specifications:

• Module power: 370 Watts
• Number of cells: 60
• Power tolerance: -0/+3 Watts
• Vmp: 35.5 Volts
• Voc: 41.9 Volts
• Imp: 10.43 Amps
• Isc: 10.94 Amps
• Module efficiency: 20.4%
• Dimensions (inches): 68.50" x 41.02" x 1.57"
• Dimensions (mm): 1740 x 1042 x 40
• Weight: 41.0 lb.

[bcroe]

I preferred to see a minimum number of sizes, built in great numbers by
many for competition to lowest price. And a size a single DIYer could
handle. Commercial aps may not see it that way. At startup here 9
years ago, those were the 60 or 72 cell panels. Being the same width
I could design an array to use either, with 5 of the larger putting out the
same voltage (for parallel strings) as 6 of the smaller. Performance or
damage replacements fit.

Lately I seem to see a trend toward larger panels, perhaps driven by
commercial needs. These do not help my DIY situation. Bruce Roe

[mike788]

Thanks all for your replies, interesting read.

I too have seen some very random claims from some manufacturers, and I've sat there scratching my head trying to work out how they've managed to get the wattage output they claim.

That LG panel seems pretty good output, especially as it's a 60 cell configuration.

I'm not in the industry, just an end user, but have been dabbling with solar designs for many years as a hobby, trying optics, mirror setups, and many other crazy ideas to try to boost the output from panels. I'm really interested in a ground mounted setup as opposed to a roof mounted one. Does anyone know the best bi-facial panel out there at the moment, again looking at around 1650x1000mm in size?

[Ampster]

Thanks all for your replies, interesting read.

I too have seen some very random claims from some manufacturers, and I've sat there scratching my head trying to work out how they've managed to get the wattage output they claim.

They use Standard Test Conditions. Look for STC in the specs

That LG panel seems pretty good output, especially as it's a 60 cell configuration.

........ Does anyone know the best bi-facial panel out there at the moment, again looking at around 1650x1000mm in size?

Best or most cost effective? Solar panels have become commoditized so price per kW from any reputable manufacturer is a good value. There are some markets that are reporting shortages in panels so the best may be the one you can find at a reasonable price. Transportation can be an issue as well. Where are you located?

[bcroe]

I'm really interested in a ground mounted setup as opposed to a roof mounted one.

In 9 years of running, I have written a lot about DIY ground mounts,
this is not a case where one design fits all situations. No chance to
optimize when constrained to a roof mount.

Of course, much controversy. Bruce Roe

[mike788]

Best or most cost effective? Solar panels have become commoditized so price per kW from any reputable manufacturer is a good value. There are some markets that are reporting shortages in panels so the best may be the one you can find at a reasonable price. Transportation can be an issue as well. Where are you located?

Thanks Ampster, this is more research than physical buying something new. I'm in the UK, and panel supply seems ok over here from browsing online. I've got a 2kW system at home (ground mounted), and a 6kW system spread across my roof at work. It was whilst fitting the 6kW system I was thinking 'Christ this is a heck of a lot of roof space!' (they're not new panels, and have lost some efficiency I guess) and got me thinking about other panels currently on the market and ways that that roof space could be drastically decreased, hence my OP about the feasibility of a 1kW single panel. I guess if someone came up with such a panel it would disrupt the market somewhat!

I don't know if you have better options available in the USA?, so in answer to your question about my question, a Bifacial panel of around 1.65sqm with the best output.

Cheers

Mike

[mike788]

In 9 years of running, I have written a lot about DIY ground mounts,
this is not a case where one design fits all situations. No chance to
optimize when constrained to a roof mount.

Of course, much controversy. Bruce Roe

Bruce, have you got a picture of your array? Can you attach pictures on here?

When you say 'much controversy', I take it you mean there are advocates for both roof and ground mount setups, which gets heated debate?

[bcroe]

image_15225.jpg

Bruce, have you got a picture of your array? Can you attach pictures on here?

When you say 'much controversy', I take it you mean there are advocates for both roof and ground mount setups, which gets heated debate?

Here is the current panel arrangement, 3 different designs built
at different times, each (in my opinion) provided real advntages
over the previous constructs. That farthest left is the newest,
solving a list of issues of the others. With net metering, they
supply ALL my heating, cooling, and electric energy needs.

I have a list of 52 reasons a ground mount array is better than a
roof mount. Some have no choice but to roof mount.

Here at 42 deg Lat, the clouds, snow, and lately smoke from the
left coast are very detrimental to solar production. Working with
the situation limits, I have sacrificed some individual panel
efficiency to get the maximum overall system energy production,
that is controversial. Others include string vs micro inverters, and
monitoring. Bruce Roe

[jflorey2]

With the advent in solar technology in Poly, Mono and now PERC and output figures rising all the time, what does everyone feel is now the theoretical maximum output from, let's say a panel sized 1650mmx1000mm using either 5",6",7" or half cell designs?

About 370 watts with current efficiencies.

With the standard formula of 1000w/sqm input to panels (STC), what are the possibilities of creating a 1650mmx1000mm single panel that could deliver close to 1kW output?

How much do you want to pay?

For GaAs dual junction cells you could hit 495 watts. You would pay around $15K for a single panel. Not worth it for your house. For your $4 million UAV? That might make sense.

For quantum well (the most efficient cells made as of today) you could get 650 watts. Expect to pay millions for such a panel, if you could even get one built.

[littleharbor2]

If you're wanting pure power output regardless of size you can get up to 700 watts. Here's an interesting article on the highest output panels.

Most powerful solar panels 2022 — Clean Energy Reviews

[SunEagle]

If you're wanting pure power output regardless of size you can get up to 700 watts. Here's an interesting article on the highest output panels.

Most powerful solar panels 2022 — Clean Energy Reviews

I did not see a cost for those panels. I would expect the higher costs can be covered by NASA or other government organizations to put on their satellites but a homeowner would not be able to afford similar ones.

[littleharbor2]

These large panels appear to only be available from the likes of Alibaba, from China, and in 10,000 watt quantities and up but the prices seem to be pretty low. I just looked at Trina 670 watt models and here is a couple pages. Of course shipping will add to the cost.

Tier 1 Brand Tsm-de21 Trina 655w 660w 670w Solar Panels 210mm Stock From Original Factory - Buy Solar Module,9bb Mono Solar Cells,Pv Module Product on Alibaba.com

Trina Solar Vertex Mono Photovoltaic Panels 650w 665w 660W 670W Solar Energy Panel Price - Buy trina solar, Photovoltaic Panels, solar energy panel Product on Moregosolar, one-stop PV products and service