Half Cell or Half Panels are ramping up production and I wanted to know how they work and are they suitable for a RV. I'm not an expert but this is what I found. Lots of sites have the basic half cell marketing information, more power, better shade tolerance, higher cost, pros and cons, etc. I found the link below that has excellent information and comparison of full cell and half cell panels and is the basis for this post using 72 full cell and 144 half cell panels.https://www.youtube.com/watch?v=AZ8VQ_zmf1M&t=34sThis link also contains excellent graphics on how full cell panels operate in the shade with bypass diodes. Based on my understanding of the above link the Half Cell panels require a new MPPT controller that can detect 2 power points - The Global Power Point and the Local Power Point and is based on the 5A half cell amp rating and the higher voltage associated with twice the number of cells in the panel and the unique cell layout. Increased shade power is dependent on the type of shade and the panel orientation to the shade. Shade may also reduce the power available for series panels as shown at time 8:30 to 10:00 in the link. 10:15 strongly suggests that heavy uniform shading like a solar farm is needed for half cut cell performance improvement. ie All modules need to be similarly shaded in the lower half on any given row (series string).My take is that half cell series panels (with the new MPPT controller) are more likely to be a disadvantage for the typical RV due to the unique shade and shade orientation required for more shade power vs the full cell panels. Plus no doubt the new MPPT with additional power point cost.What's your take on the video?

Hi CA Traveler,Nice find on the video.The controller should lock onto what they are calling the Global MPP.individual string on each panel would be better, but I've not seen any that are not for grid tied installations. (I've not looked for a couple of years).

CA Traveler wrote:Half Cell or Half Panels are ramping up production and I wanted to know how they work and are they suitable for a RV. I'm not an expert but this is what I found. Lots of sites have the basic half cell marketing information, more power, better shade tolerance, higher cost, pros and cons, etc. I found the link below that has excellent information and comparison of full cell and half cell panels and is the basis for this post using 72 full cell and 144 half cell panels.https://www.youtube.com/watch?v=AZ8VQ_zmf1M&t=34sThis link also contains excellent graphics on how full cell panels operate in the shade with bypass diodes. Based on my understanding of the above link the Half Cell panels require a new MPPT controller that can detect 2 power points - The Global Power Point and the Local Power Point and is based on the 5A half cell amp rating and the higher voltage associated with twice the number of cells in the panel and the unique cell layout. Increased shade power is dependent on the type of shade and the panel orientation to the shade. Shade may also reduce the power available for series panels as shown at time 8:30 to 10:00 in the link. 10:15 strongly suggests that heavy uniform shading like a solar farm is needed for half cut cell performance improvement. ie All modules need to be similarly shaded in the lower half on any given row (series string).My take is that half cell series panels (with the new MPPT controller) are more likely to be a disadvantage for the typical RV due to the unique shade and shade orientation required for more shade power vs the full cell panels. Plus no doubt the new MPPT with additional power point cost.What's your take on the video?This is nothing new, I have been using a 24V 325W 120 split cell (or half-cell depending on the company) panel for three years now on my camper. Yes, they are more efficient and do much better in low light and shade. to give you an example of the improvements in efficiency I got, my 5th wheel has a 12V 480W solar set up run off a PWM controller and the best ever see is 21 Amps of charging, where as my MPPT with the 325watt split cell set up routinely gives me 22 to 23 amps in the middle of the afternoon. I also get more charging power in the early morning and lait at night. in the 5th wheel it's not uncommon for me to have to wait till 8:30 to 9 am before charging registers, the camper with the split cell will be putting out 0.2 amps at 6am and you can watch it rise as it gets brighter out. shading I can't speak on with technical data as I don't measure the panels as I observe the shadows, but I take the camper to mostly partial shaded sites in the middle of the forest and I have never had an issue charging. I am also looking into replacing the panels on the 5th wheel with similar panels and a better controler to improve their performance. Steve

Steve, I've seen similar results with MPPT, with leafy shade and panel voltage at 20V, ramping up in 10V increments to 90V due to the bypass diodes and serial panel connection. I've captured this data and posted it online in the past.The video compares a given cell technology configured as a full cell or cut in half for 2 cells. My take is that half cell panels require a unique shade pattern (not likely for a RV IMHO) and a new MPPT controller that detects 2 power points unlike most current MPPT controllers that detect a single power point. My take is that the split cell panels and new MPPT controller will cost more and produce lower shade power for series panels for the RV environment. Parallel panel power will have no improvement vs the full cell environment.

The terminology may be confusing. From the video the new MPPT controller is referred to as "Global Maximum Tracking" MPPT. The "Local MPP" power point is the same as for the full cell power point and the "Global MPP" is associated with the half cell amps and 2x voltage for 2 cells.

CA Traveler wrote:My take is that the split cell panels and new MPPT controller will cost more and produce lower shade power for series panels for the RV environment. Parallel panel power will have no improvement vs the full cell environment.ahh, I see, I missed it. The panels are nothing new, but it is the controller that is new. I was just trying to search, and I don't see any dual peek MPPT controllers for sale, so personally I am not going to worry about it until they are for sale. What I do see though, is it shouldn't be too much more than the cost for a normal MPPT once all the other companies start doing it. If it isn't too much more (probably still be cheaper than a PWM Victron ;) ) I defiantly will get one as it looks like it will help quite a bit in partial shading. I think this would be more of a fit for rv's with fixed panels than residential as normally when you set up a residential solar array it is in a clearing or on the roof with no obstructions. I guess int he case where the neighbor has lots of tall trees it would help also...I missed the part about series parallel, that's a tricky one.. the video only takes about 1 panel but even in series I think it might help, my reason being if the normal one shuts down the bypass and only delivers 5 ish volts through for example then you are only adding 10 volts to the next panel in series so let's pick 28V as a full output and two in series that would give you 33v. but if you have this "new MPPT" then the first panel will give you let's say 18V (I'm making up the numbers so don't quote me) so that would give you 46V total. if I am thinking right, I'll have to do some more reading yet, but these should be great for campers who are in partial shade depending on the time of day.

Solar Panel Half Cell Discussion | Good Sam Community

CA_Traveler
Explorer III
Apr 11, 2023
The terminology may be confusing. From the video the new MPPT controller is referred to as "Global Maximum Tracking" MPPT. The "Local MPP" power point is the same as for the full cell power point and the "Global MPP" is associated with the half cell amps and 2x voltage for 2 cells.
CA_Traveler
Explorer III
Apr 11, 2023
Steve, I've seen similar results with MPPT, with leafy shade and panel voltage at 20V, ramping up in 10V increments to 90V due to the bypass diodes and serial panel connection. I've captured this data and posted it online in the past.

The video compares a given cell technology configured as a full cell or cut in half for 2 cells. My take is that half cell panels require a unique shade pattern (not likely for a RV IMHO) and a new MPPT controller that detects 2 power points unlike most current MPPT controllers that detect a single power point.

My take is that the split cell panels and new MPPT controller will cost more and produce lower shade power for series panels for the RV environment. Parallel panel power will have no improvement vs the full cell environment.
StirCrazy
Moderator
Apr 11, 2023
CA Traveler wrote:
Half Cell or Half Panels are ramping up production and I wanted to know how they work and are they suitable for a RV. I'm not an expert but this is what I found. Lots of sites have the basic half cell marketing information, more power, better shade tolerance, higher cost, pros and cons, etc. I found the link below that has excellent information and comparison of full cell and half cell panels and is the basis for this post using 72 full cell and 144 half cell panels.

https://www.youtube.com/watch?v=AZ8VQ_zmf1M&t=34s
This link also contains excellent graphics on how full cell panels operate in the shade with bypass diodes.

Based on my understanding of the above link the Half Cell panels require a new MPPT controller that can detect 2 power points - The Global Power Point and the Local Power Point and is based on the 5A half cell amp rating and the higher voltage associated with twice the number of cells in the panel and the unique cell layout. Increased shade power is dependent on the type of shade and the panel orientation to the shade. Shade may also reduce the power available for series panels as shown at time 8:30 to 10:00 in the link. 10:15 strongly suggests that heavy uniform shading like a solar farm is needed for half cut cell performance improvement. ie All modules need to be similarly shaded in the lower half on any given row (series string).

My take is that half cell series panels (with the new MPPT controller) are more likely to be a disadvantage for the typical RV due to the unique shade and shade orientation required for more shade power vs the full cell panels. Plus no doubt the new MPPT with additional power point cost.

What's your take on the video?

This is nothing new, I have been using a 24V 325W 120 split cell (or half-cell depending on the company) panel for three years now on my camper. Yes, they are more efficient and do much better in low light and shade. to give you an example of the improvements in efficiency I got, my 5th wheel has a 12V 480W solar set up run off a PWM controller and the best ever see is 21 Amps of charging, where as my MPPT with the 325watt split cell set up routinely gives me 22 to 23 amps in the middle of the afternoon. I also get more charging power in the early morning and lait at night. in the 5th wheel it's not uncommon for me to have to wait till 8:30 to 9 am before charging registers, the camper with the split cell will be putting out 0.2 amps at 6am and you can watch it rise as it gets brighter out. shading I can't speak on with technical data as I don't measure the panels as I observe the shadows, but I take the camper to mostly partial shaded sites in the middle of the forest and I have never had an issue charging. I am also looking into replacing the panels on the 5th wheel with similar panels and a better controler to improve their performance.

Steve
pianotuna
Nomad III
Apr 11, 2023
Hi CA Traveler,

Nice find on the video.

The controller should lock onto what they are calling the Global MPP.

individual string on each panel would be better, but I've not seen any that are not for grid tied installations. (I've not looked for a couple of years).

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