what solar to get these days?

[prelude]

Hi all,

It has been a while since I looked at solar so I had to do a lot of digging and I have come to the following conclusions:



mono crystalline panels seem to be the most efficient in terms of space vs power produced
amorphous work WAY better in partial shade
most stuff comes from china these days
most (all?) stuff from china is mono or poly


I ordered myself 3 5 watt panels of each technology and I have confirmed that shade on a mono or poly panel is killing for performance but the amorphous seems to degrade in power output in direct relation to the amount of shade. If people want/need proof I guess I can make a short story about this at some point.

In any case, I started digging and digging deep/hard for amorphous panels but it seems that "competition" has done it's job and the chinese have won this battle. Since the market is mostly domestic and people want the most bang for their buck mono panels are all the rage and the very few amorphous producers that still exist reside in japan for example and they have stepped out delivering to europe all together. Also, their panels are huge and not suitable for a car I should think :)

The only amorphous panel I could find was the redarc blanket but imho a blanket or portable solar panel is best in mono/poly form since it is a tad bit smaller and shade is most likely not an issue since you can put it down wherever you can catch the most sunlight. On a vehicle however I want my car and rtt in the shade and the panels would still need to work properly so amorphous is the go here.

First of, are my findings / assumptions above in agreement with the brain trust here? ;)

Second, I did do a search on this forum of course and the unisolar panels seem to be a good choice. I found a lot NOS and would consider buying those, although they are old, since they seem to be one of the few decently sized panels that will actually fit my car and are of the type that I need. Since they are unboxed I guess UV degradation and all that would not be a big deal...

If this is no longer the way to go, what is?

Thanks!
-P

[NavyDiver]

Hi all,

It has been a while since I looked at solar so I had to do a lot of digging and I have come to the following conclusions:



mono crystalline panels seem to be the most efficient in terms of space vs power produced
amorphous work WAY better in partial shade
most stuff comes from china these days
most (all?) stuff from china is mono or poly


I ordered myself 3 5 watt panels of each technology and I have confirmed that shade on a mono or poly panel is killing for performance but the amorphous seems to degrade in power output in direct relation to the amount of shade. If people want/need proof I guess I can make a short story about this at some point.

In any case, I started digging and digging deep/hard for amorphous panels but it seems that "competition" has done it's job and the chinese have won this battle. Since the market is mostly domestic and people want the most bang for their buck mono panels are all the rage and the very few amorphous producers that still exist reside in japan for example and they have stepped out delivering to europe all together. Also, their panels are huge and not suitable for a car I should think :)

The only amorphous panel I could find was the redarc blanket but imho a blanket or portable solar panel is best in mono/poly form since it is a tad bit smaller and shade is most likely not an issue since you can put it down wherever you can catch the most sunlight. On a vehicle however I want my car and rtt in the shade and the panels would still need to work properly so amorphous is the go here.

First of, are my findings / assumptions above in agreement with the brain trust here? ;)

Second, I did do a search on this forum of course and the unisolar panels seem to be a good choice. I found a lot NOS and would consider buying those, although they are old, since they seem to be one of the few decently sized panels that will actually fit my car and are of the type that I need. Since they are unboxed I guess UV degradation and all that would not be a big deal...

If this is no longer the way to go, what is?

Thanks!
-P

Love your work. Link has done some of that an more (http://dkasolarcentre.com.au/)

A side note was a grid outage test I did yesterday you might be interested in. At work at 8am and turned the grid off. Powered up everything in my office. I worked until 12 happily with lights, computers and heating all running then checked the battery. They were close to 100%. I forgot to turn of the Solar PV. It was a bright cold day. PV powered everything and then recharged my 2 10kwh flow batteries. Sort of a test fail in a nice way[thumbsupbig]


Noted some new much higher capacity panels are about to come out. Only thing I wish I had was about 2 times the solar PV than I have now.

I will be replacing my batteries with a hydrogen electrolyzer in several years to store my unused generated electricity.

My biggest tip is to spend just a little more for a hybrid inverter now so when the grid fails you PV can still help.

[prelude]

Nice site! It'll take me a while to go through all that data but it should indeed be an interesting endeavor.

Funny you should mention a hydrogen electrolyzer. I have been looking for longer term, higher capacity storage for an off grid application. I will need to look in to that a bit further as well. For now however, I was mostly interested in vehicle based solutions. Since my car would be parked in shady areas I recon amorphous would be the way to go for now. I am currently hovering over the "buy" button for those unisolar panels but am not sure if there is anything newer that would work better.

Decisions decisions...

-P

[DiscoMick]

Can I just mention there are some house panels around which are actually two panels in one. This means if there is sun on one half the other half still works. The two halves are wired separately.
Also, what are your vehicle needs? You may not need that big a panel depending on usage.
I have an 80 watt eBay cheapie on the roof of the Defender, wired through a PW controller to the starting battery, since you always want to be able to start your vehicle. A Traxide unit connects it to the secondary battery, which powers a 30 litre Evakool fridge.
I find this setup works fine. I can run the fridge for a week while camped no problems, as long as I park in the sun. Solar is most efficient at about 25 degrees, so it does not need to be really hot to work.
So your needs will determine what you buy.

[prelude]

Mick,

I have heard of those panels I think. Or at least something similar.

To answer your question: My vehicle needs are fairly broad and like the vehicle itself it will be a compromise. I am planning to take my truck around the world, although the first continent on the bucket list will be oz. So, although I would do a fair amount of driving in a relatively short amount of time (ie. the alternator will keep the batteries topped up) I do intend to stick around nice campsites for a couple of days. Since the panel will be mounted on the vehicle, next to my rooftop tent I would like to park my car in the shade since have the tent in the full sun is no fun :) This also means that the solar panel would be in the shade as well, at least partially (leaves and branches) so I would need a panel that can perform well in those situations. My electrical needs vary. Since I am a ham radio operator I imagine that I will be operating the radio regularly, be running a 50 liter national luna weekender twin and some lights / charge gear. I reckon 50amps a day and I will be carrying around 200ah of battery capacity. All in all, if I can stretch 4 days without running the engine and not drain the batteries below say 20-50% that would be great. Since I would be doing quite a few tough tracks the panel needs to be somewhat bullit proof, though I could make a flipover bracket that would hold the maxtraxx on one side and the panel on the other. When driving, flip the maxtraxx up, solar is not needed, and when stationary flip the other way around... Still, I prefer the panel to be sturdy.

Cheers,
-P

[Vern]

Do you mean panels with bypass diodes?

[prelude]

bypass diodes seems to be a technical term used to suggest the panels operate better in the shade. I am not sure of they work as well as the amorphous kind.

See: YouTube (https://www.youtube.com/watch?v=FQsuOAooeKA)

and: YouTube (https://www.youtube.com/watch?v=3qCMCy5H9FA)

I am looking for a panel that can do as demonstrated and thus of that type. I believe the unisolar US-64, which was popular some years ago (I found some references to them on this forum), is of this type. I can get my hands on NOS of these panels and wonder if it is worth it or if I should go a different route.

-P

[trout1105]

Mick,

I have heard of those panels I think. Or at least something similar.

To answer your question: My vehicle needs are fairly broad and like the vehicle itself it will be a compromise. I am planning to take my truck around the world, although the first continent on the bucket list will be oz. So, although I would do a fair amount of driving in a relatively short amount of time (ie. the alternator will keep the batteries topped up) I do intend to stick around nice campsites for a couple of days. Since the panel will be mounted on the vehicle, next to my rooftop tent I would like to park my car in the shade since have the tent in the full sun is no fun :) This also means that the solar panel would be in the shade as well, at least partially (leaves and branches) so I would need a panel that can perform well in those situations. My electrical needs vary. Since I am a ham radio operator I imagine that I will be operating the radio regularly, be running a 50 liter national luna weekender twin and some lights / charge gear. I reckon 50amps a day and I will be carrying around 200ah of battery capacity. All in all, if I can stretch 4 days without running the engine and not drain the batteries below say 20-50% that would be great. Since I would be doing quite a few tough tracks the panel needs to be somewhat bullit proof, though I could make a flipover bracket that would hold the maxtraxx on one side and the panel on the other. When driving, flip the maxtraxx up, solar is not needed, and when stationary flip the other way around... Still, I prefer the panel to be sturdy.

Cheers,
-P

It sounds like a foldable solar blanket ( most have struts to make them self standing) Instead of fitting a solar panel to you vehicle would suit your needs better.
That way you Can park in the shade and still deploy your panel in the sun[thumbsupbig]

[DiscoMick]

You could carry a second folding panel to place in the sun and connect when parked, in addition to the fixed panel on the roof. I have one.

[prelude]

I am looking for a solar blanket or portable panel indeed. This could be a "simple" mono or poly variant since popping it down in the sun should be no problem. The only reason for having a fixed panel is for those occasions where I would go visit some area where you leave the car parked and locked. A fixed panel reduces the chance of theft greatly but still keeps the fridge running and batteries happy.

Cheers,
-P

[DiscoMick]

I just bought a cheapie Kings 200w blanket to supplement the fixed panel on the roof.
BTW I have recently been looking at the flexible panels sold by Marine Tech stores, which seem well priced.

[prelude]

Do you happen to know the tech used in the blanket? And the panels for that matter. As my op suggested: amorph seems to have gone the way of the dodo so I wonder what you are using

Cheers,
-P

[DiscoMick]

Monocrystaline. Details of the Kings here:

Adventure Kings 200W Portable Solar Blanket + 10m Lead For Solar Panel Extension - 4WD Supacentre (https://www.4wdsupacentre.com.au/adventure-kings-200w-portable-solar-blanket-10m-lead-for-solar-panel-extension.html)

It was Road Tech Marine. Sorry about tge wrong name. Details here:

Search flexible solar panel | Road Tech Marine (https://www.roadtechmarine.com.au/search'text=flexible+solar+panel)

[NavyDiver]

Hi Prelude, Visited this place to take an inverter back recently (https://energyconnections.net.au/case-studies). The do a lot of work in off grid and camping trailers/caravans and just might be of interest to you.

Have a nice day.

[prelude]

Thanks for the input guys.

I have decided for now to hold of on the US-64 NOS panels. They are 12 years old, although new and not exposed to UV solar cell degradation must have set in. Also I can find double the power for half the price and half the size locally in mono/poly guise and my gut feeling tells me that even with such reduced shade performance, having twice the power in the same space would compensate sufficiently.

We are just unfortunate enough that large land based installations get the cream of the crop in terms of solar panels and 12v (usually 23v voc) panels have become quite the underdog.

Regarding the land based setup, I was not looking for a solution there yet since I have a grid connection down here (since I believe grid-tie solar to not be environmentally friendly) but navydiver has provided me with some really good information regarding that for future reference.

When I get the chance I will continue my experiment with the small panels :)

Cheers
-P