1120 AF Build in Norway

[charlieaarons]

“Zero power”?
The incident power with a clear sky is about 1000w/sq m times (sin α), α = angle of sun relative to horizon. Then one multiplies that by efficiency of panel; currently ~19%. So at my latitude, 61N, at solar noon (2.05 pm currently), today zenith of sun is 51 deg. Sin 51 = 0.777. With a 1 sq m 190w panel, the panel will have a rated electrical output of about 147.66w, at solar noon. Before multiplying by temperature correction factor. Clouds are a bigger issue than latitude in the summer. Obviously solar panels are useless at 61N December and January especially. But most travel at high latitudes is in the warmer parts of the year, between the spring and fall equinoxes.
MPPTs are very good inventions.
I can tell you by extensive personal experiences that solar panels work at 61N at the equinox (assuming not being covered with snow in the spring), but with the predictable 55% decrease in daily output compared to places and dates where the sun is ~vertical at solar noon.
Lithium batteries have fancy charge controllers with narrow allowed temperature ranges (like +5 to +45C). But AGMs will charge under a wider range of conditions.
Lastly: saw a burned out class C being towed a couple of weeks ago. What do you all think the most likely source of that was?

 

[Joe917]

Going fully electric has become a very popular choice.

I would make 2 observations that may be of assistance

I would consider being able to tilt the solar panels up to about 45 degrees to face the sun and be prepared to be constantly moving your vehicle to ensure that it remains so. The reason being that if mounted horizontally then there are many locations in the world where you will get Zero power from your panels as the sun will never get up to the required angle needed to create charge. I have been in this position where we were applying sun cream but zero charge.

Secondly you need a way to override the chargers tepreture safety mechanisms. If the ambient tempreture in your truck is high, maybe 38 degrees plus. Most modern intelligent chargers will simply shut down and refuse to charge the batteries as its tempreture feedback is telling it that the batteries are cooking . Again we had this in Brazil. Beautiful sunny hot days and zero charge from any device .

Hope this gives you the heads up on a couple of issues we have discovered

Neil

Sorry Neil , our experience is the opposite, with permanent flat mounted panels we almost always get to full charge even in high latitudes. Our alarm for not reaching full charge in a 5 day period has been activated only a couple of times in the last 7 years. Our system has never stopped charging in high temperatures. We have FLA batteries and a Morningstar MPPT charge controller with temperature correction.
There is something strange that you were getting zero charge in the heat, disabling safety mechanisms is probably not the best idea.
Tilting panels and having to constantly move the vehicle is more trouble than its worth.

 

[Geo.Lander]

Some thoughts:

Depending on the panel configuration and wire (voltage drop) size the MC4 connectors on the controller may not be large enough.

We've camped close to/ downwind from people that run a engine (diesel) to charge batteries. A generator would be better in those situations.

Large enough shore power supply to supply 2 appliances or be able to plug each appliance into separate shore power outlets. The 3 hottest (105F) days of our last trip we ran the AC for an hour in the evening. One AC ran off (3000W Multiplus - 167A@12VDC) solar (1.3KW roof top + 1.3Kw portable) and the other was AC plugged into a 2000W generator.

The 24V-12V converter could be fed from the 24V distribution panel.

[/QUOTE]

Thanks Alloy!

The panels im thinking of should have max series connected VOC of 200V, which should work well with that controller, I know the current limit is 30A for those cables so I am just within those limits to make one series array of 3 panels, if not I will need to take one panel out from that array. Not ideal as I am aiming for the max VOC the charger can handle to aid winter charging conditions.

I was planning on one 16A shore power line, I am not sure when I will actually use it thou apart from keeping the battery charged at home port, the Multiplus-ii can act as a UPS and has some intelligent switching while plugged in. We were planning AirCon in the future and might go with a roof mounted Truma unit or maybe even one of those 24v marine units from the US (i dont remember the name).

The more im looking at DC distribution the more im leaning towards using the Victorn Lynx system, it enables VECan communication between all the fuses and 1000A shunt and I was planning on the GX network anyway so it just makes a bit more sense...

 

[Geo.Lander]

1) regarding spare tire weight, recommend having only 1 mounted. That will save ~40kg at least up on the roof. Cracked wheels are almost always weldable. And destroying 2 wheels is much less probable than destroying 2 tires.

Nice, this was going to be my plan for longer trips! I also plan to outfit a small welder in the truck after some time.

2) I too am going propane free. I found that a US type bbq 9kg canister lasts about 6 months or more when in Australia, for cooking. Based on that I calculated mean daily use of 2200btu/0.66 kwh/day. 55Ah in 12v system. I currently have 5 x 1 sq m panels, nominally 623w. I am upgrading them to new 190s. Just the 327w difference should generate ~98 Ah/day on sunny days in temperate or tropical latitudes. Much less in Alaska on cloudy days. But 285Ah nominally output of the whole system should do fine; I don’t have air conditioning.

With the efficiency of the newer Bifacial arrays (LG NeON H LG435N2T BiFacial 435W) connected to a high voltage (VOC) controller it should be possible to charge far longer into the evening and during shaded periods. I am hoping at least.

Regarding lack of air conditioning, I am installing a 2nd vent/fan above the stove (3rd counting bathroom) 2 more very small internal fans for over the front table/vent area, and when I pass through Germany on the way to Southern Africa in 2022 I will have Unicat install their upgraded actually effective mosquito net system for my 5 opening windows. Vents and fans when on low speed draw infinitesimal power compared to air conditioning.

We are still a bit unsure about AirCon, very tempted by the smaller Truma untis but I think fitting something in the drivers cab is the priority when we get out truck back. Can I ask what windows you have? Would it be worth looking into those small marine fans for the box?

 

[Geo.Lander]

I would consider being able to tilt the solar panels up to about 45 degrees to face the sun and be prepared to be constantly moving your vehicle to ensure that it remains so. The reason being that if mounted horizontally then there are many locations in the world where you will get Zero power from your panels as the sun will never get up to the required angle needed to create charge. I have been in this position where we were applying sun cream but zero charge.

Nice tip, i was considering a rig like this until a came across the transparent Bifacial split cells, they come in from 400-450w and can charge at very low irradiance ratings, because they are Bifacial they charge on both sides so I am planning on mounted them with a small gap, hoping the white GRP will reflect some power

Would you ever consider side mounting a panel or 2?

Secondly you need a way to override the chargers tepreture safety mechanisms. If the ambient tempreture in your truck is high, maybe 38 degrees plus. Most modern intelligent chargers will simply shut down and refuse to charge the batteries as its tempreture feedback is telling it that the batteries are cooking . Again we had this in Brazil. Beautiful sunny hot days and zero charge from any device .

The Victron unit im looking at is rated from -30 - +60 (full output to +40). The BMS I am using is programmable of course and I am planning on using the canbus interface on the BMS to interface with the Cerbo GX box for monitoring the battery temperature. There is also an option to add the Victron sensor I suppose too, I suppose mainly to act as a cold temp cutoff... I still have a lot of decisions to make

Hope this gives you the heads up on a couple of issues we have discovered

Really appreciate the advice! please please keep the tips coming.

 

[Alloy]

Thanks Alloy!

The panels im thinking of should have max series connected VOC of 200V, which should work well with that controller, I know the current limit is 30A for those cables so I am just within those limits to make one series array of 3 panels, if not I will need to take one panel out from that array. Not ideal as I am aiming for the max VOC the charger can handle to aid winter charging conditions.

I was planning on one 16A shore power line, I am not sure when I will actually use it thou apart from keeping the battery charged at home port, the Multiplus-ii can act as a UPS and has some intelligent switching while plugged in. We were planning AirCon in the future and might go with a roof mounted Truma unit or maybe even one of those 24v marine units from the US (i dont remember the name).

The more im looking at DC distribution the more im leaning towards using the Victorn Lynx system, it enables VECan communication between all the fuses and 1000A shunt and I was planning on the GX network anyway so it just makes a bit more sense...
[/QUOTE]

My system was designed to perform in the worst conditions. From Nov - March (49degres North) with no direct (trees/mountains) sun the system (2.6kw) will produced 20A@12VDC
- Panasonic HIT "19.7%" - not transparent but have similar reflective tech as LG
- 4 panels on the roof can be tiled 4 ways. In winter tilting these panels will produce 2X to 100X the power.
- 4 portable panels. In winter it is much easier/safer to tilt these and remove the snow.
- wire calculated at 1.2X max (high altitude and reflections) amperage and with a 1% voltage drop
- 100 mm clearince from roof. Protects the roof and is the most effective cooling distance.
- 70VOC so the panels are connected in parallel to reduce the effects of shading.
- low temp winter morning start up calculated at -40C/-40F (1.25%) so 70VOC x 1.25% = MAX VOC of +/- 88 volts. Controller is a Victron 150/100

 

[Neil]

Although my Morningstat Tristar MPPT has an operating range of up to 45 degrees it would appear that it relies totally on the remote battery sensor to monitor the battery tempreture
I cannot find the vicron or morningstar tempreture limits for charging Gel batteries but I suspect it will cease to charge at much less than 45 degrees maybe below 40 , which would explain my issues when the ambient tempretures were so high.

This battery tempreture limit might vary depending on which charging algorithm you have selected to match your batteries.

I know from fireside discussions that this is quite a common occurance

Neil

 

[palebluewanders]

Regarding these 400+ W solar panels: I read somewhere that anything over ~200W was too big for off roading due to the vibration on the glass plate, and with the bifacial panels you've got massive solid glass plates on both sides. To be clear, this is a random comment I read on a forum somewhere and I have no experience or other references to back it up with, but just curious if this is something you've researched and/or considered?

 

[Joe917]

I have 200 000km with 2 X 315 Watt residential panels on the roof. Many washboard miles and tree branches. No worries.

 

[Geo.Lander]

Regarding these 400+ W solar panels: I read somewhere that anything over ~200W was too big for off roading due to the vibration on the glass plate, and with the bifacial panels you've got massive solid glass plates on both sides. To be clear, this is a random comment I read on a forum somewhere and I have no experience or other references to back it up with, but just curious if this is something you've researched and/or considered?

Right, I actually looked into that and the testing standards / certifications as this came up the the self build book. However, all the testing specs are behind paywalls at the IEC/UL/ISO. So instead i looked at the testing methods to see what would come close to the off-road use and snow loading they would most likely suffer under. What I found was testing methods called Dynamic Mechanical Loading (DML), Inhomogeneous Mechanical Loading (IML) and Mechanical Loading (ML) testing and covering those basis assumed IML and DML specs are most relevant to off-road usage scenarios,. However! I got pretty tired reading though all the TUV and UL docs, didnt make much sense to me but I found what I was looking for. Bifacial panel also have glass on both sides (2.8 mm tempered glass). They have a pretty high load ratings, far better than older panels of much smaller sizes form only a few years ago:-

"With reinforced frame design, LG NeON® H can endure a front load up to 6,000Pa (represents snow height of normal snow of more than 1,8 meters) and a rear load up to 5,400Pa (represents wind speed of up to 93 m/s, compare max. wind speed of Hurricane Katrina 2005 of max. 75 m/s)."

I am pretty satisfied with those numbers. But I have no practical knowledge of fitting any panels to any moving objects We will see what happens, I want me big panels!

 

[palebluewanders]

Wow, that is some good research! Thanks for the info. In this case I'll probably also get me some of these big bifacials. :⁠)

 

[Alloy]

Right, I actually looked into that and the testing standards / certifications as this came up the the self build book. However, all the testing specs are behind paywalls at the IEC/UL/ISO. So instead i looked at the testing methods to see what would come close to the off-road use and snow loading they would most likely suffer under. What I found was testing methods called Dynamic Mechanical Loading (DML), Inhomogeneous Mechanical Loading (IML) and Mechanical Loading (ML) testing and covering those basis assumed IML and DML specs are most relevant to off-road usage scenarios,. However! I got pretty tired reading though all the TUV and UL docs, didnt make much sense to me but I found what I was looking for. Bifacial panel also have glass on both sides (2.8 mm tempered glass). They have a pretty high load ratings, far better than older panels of much smaller sizes form only a few years ago:-

"With reinforced frame design, LG NeON® H can endure a front load up to 6,000Pa (represents snow height of normal snow of more than 1,8 meters) and a rear load up to 5,400Pa (represents wind speed of up to 93 m/s, compare max. wind speed of Hurricane Katrina 2005 of max. 75 m/s)."

I am pretty satisfied with those numbers. But I have no practical knowledge of fitting any panels to any moving objects We will see what happens, I want me big panels!

The short side of my roof panels are fastened/hinged and there are support blocks at the center of the long side. I'm more worried about the panels delaminating vs. cracking.

Our snow is wet/heavy. The snow is removed before it is + 400mm.

The portable panels have fallen over several times when propped up. The 2-3mm alum frame is dented but the glass hasn't broken.

 

[Geo.Lander]

Question! steps facing towards to cab or rear?

 

[Madoxen]

At least if facing the rear you can use them for the garage locker

 

[Joe917]

Neither, but if your heart is set on that placement face them to the rear, if you drive off with them down they might survive.