Solar on my touring campervan.. a waste of time ?

[contravertial]

When touring Europe for example, I wouldnt expect to be in one place more than a day or two.

The leisure batteries would be continually topped up by all the driving.

It seems to me that the loss of aerodynamics of rigid solar panels on the roof of a boxer would negate the energy gained from solar .. especially if the battery is close to full all the time from all the driving. It could even cost money!

The flexible solar panels are more aero-dynamic but there is a lot of negative comments regarding efficiency and durability ?

Backup you say ? On shore plug in at a campsite or EV charger if you got stuck maybe.

I guess it comes down to how many days do I need to survive off grid.

Any thoughts appreciated

 

[Squiffy]

I've travelled the continent each year for 20 years and have always had atleast a 120w panel on the roof. Like you I have rarely stayed longer than a day in one place, if your saying that the air resistance of solid panels on the roof would negate any power gained by them, I have to disagree, I have noted that the mpg advised by Fiat on my particular Ducato is 32.5mpg and I've constantly logged exactly 32mpg with my vehicle actually weighing in at 3620kg mass weight over the last two years and in the previous 9 years although I carry a generator I've never had to use it. I put this not only down to constant travelling and recharge by the alternator but also mppt charging from the solar panel/s when static. Believe me we also are great viewers of TV and radio when abroad as well so we never have been economic on the twelve volt system. Phil.

Don't forget that once stopped the battery bank will start to discharge with all 12volt use but if you have solar panels they will run most of what you need without touching the battery storage until ofcourse the sun goes in..

 

[trevskoda]

Mine keep the electric 230v fridge running through a 600w smart inverter, so if stopped the fridge is drawing but panels keep the batts up to dark, the batts will last well into next day so it works for me, mine are behind a high roof nose so little or no drag.

 

[Squiffy]

I would love to see a wind tunnel smoke test on Sevel vans, as my impression is that due to the nose shape and screen to roof top there would be very little drag on skylights/folded sat dish and solar panels as I think they would all be in a natural low pressure area on the roof which would be there regardless of things on the roof and so the drag would be the same with or without the extras fitted. This is just a theory and would only be substantiated one way or the other with a wind tunnel smoke test. Phil

 

[HTF]

My 450W 2000x1000 mm solar panel has double function Power and shade

 

[RV2MAX]

The size of your battery bank and B2B charge will be a bigger factor if you are constantly on the move .JMHO

 

[Duckato]

@contravertial
You need to better qualify your reasoning
if like me you have a lithium bank plus a high output b2b then the ability to charge at high current during a drive can to a degree negate having solar, however I would never be without solar simply because we are then free to be off grid pretty much until we run out of food or water.

however if you are trundling around with an archaic inefficient split charge setup cobbled to a couple of cheap lead acid batteries, then they will not get to a 100% without doing hours and hours of driving, plus because lead acids need to be maintained ideally above 60-70% to maximise longevity, then a solar setup that can provide the correct bulk, absorption and float charge voltages during daylight hours even whilst driving will 100% always be worthwhile.

Ultimately if your setup works for you then fine
I am not bothered in the slightest by the minuscule effect on mpg at a sedate 50-60mph the stuff on my roof may account for I.e 4 panels, led lightbar, max fan, satellite dish, tv aerial 4g aerials etc.

Obviously if I was driving like a pilllock at 80 mph+ everywhere then maybe aerodynamics might be a bit more of a concern

 

[MarkJ]

The leisure batteries would be continually topped up by all the driving

Are you sure? I say that because I read a thread elsewhere (and can't find it now) talking about the surprising inefficiency of engine charging. For example, a 30A Orion from Victron only delivers 30A under very ideal conditions, and if you had seriously depleted the batteries by, say, stopping in one place for a couple of long days, with only a short hop next day, you might be disappointed.

Rather than have your itinerary compromised by your battery reserves, I'd go for some solar myself.

 

[trevskoda]

Are you sure? I say that because I read a thread elsewhere (and can't find it now) talking about the surprising inefficiency of engine charging. For example, a 30A Orion from Victron only delivers 30A under very ideal conditions, and if you had seriously depleted the batteries by, say, stopping in one place for a couple of long days, with only a short hop next day, you might be disappointed.

Rather than have your itinerary compromised by your battery reserves, I'd go for some solar myself.

Hence why i have old school non smart altanator and home built electrics with a votronic solar regulator, i also have a switch and h duty 200a relay to connect les and starter batteries for a jump start, it also bypasses the old bus diode blocker which redudced the voltage to 13.6, now once i start and get the fan belt going witout squeeling i bump the switch and bingo 14.4v and 90ah alt doing the biz along with 200w solar.

 

[Millie Master]

Once whilst undertaking an almost 5,000 mile European tour, including extensive mileage in the alps, my 2008 Renault Master 2.5 dCi 100 averaged almost exactly a corrected 40 mpg.!
It has 2 quite large solar panels on the roof along with 3 roof vents, however they are all in line and the front edge of the first solar panel is faired into the bodywork. Whether or not this modification helped the aerodynamic efficiency of what is already known to be one of the more aerodynamic vans on the market, heaven only knows.

All I do know is that without the solar panel efficiency we would be very short changed with our needs for electrical power seeing as we only have a 12v fridge!

Phil