I’ve been noodling ideas for maximum solar on my next van, which will be a Sprinter or Transit Shorty. I know some members here think solar is not worth the effort, but I find it a valuable resource for free energy on my current van with four 100W panels feeding a 440AH AGM battery pack.
It occurred to me that one could get 1000W of solar on the roof of a short van by using high quality panels like the Sunpower X21-345 residential solar panel line. These panels are 44.2” x 61.3” that could be mounted at the top of a roof rack in a set of three giving 1035W of solar. First problem is they are not sold separately and only as part of an installation by authorized dealer. There are other high output panels available, but many I’ve looked at are just too large to fit on a van.
Not a fan of the flexible panels widely used on vans today. They are a compromise in efficiency and lifespan. Quality glass panels are rated to withstand snow, wind, and hail. I’ll keep looking.
The largest array I know of is the Advanced RV Solar Womp at 1250 watts and it was built on a rack above the roof to get all the other roof functions on. The owner stated he would not do that again if he built another B. That was on a longer Sprinter.
I’m going the opposite way with a short Sprinter. With a second alternator and large 800ah or more lithium batteries especially a Volta system having solar is not a percentage factor in contribution. I have 420 Watts now. Since I am now storing in a heated garage I have less incentive. I may opt for no Solar at all and may install two to three skylights to make the B more open. That takes a lot of real estate on the roof along with the Maxxfan and AC.
The largest array I know of is the Advanced RV Solar Womp at 1250 watts and it was built on a rack above the roof to get all the other roof functions on. The owner stated he would not do that again if he built another B. That was on a longer Sprinter.
I’m going the opposite way with a short Sprinter. With a second alternator and large 800ah or more lithium batteries especially a Volta system having solar is not a percentage factor in contribution. I have 420 Watts now. Since I am now storing in a heated garage I have less incentive. I may opt for no Solar at all and may install two to three skylights to make the B more open. That takes a lot of real estate on the roof along with the Maxxfan and AC.
What is your guestimate of the cost difference between the Volta setup and the Delco 12V alternative?
Take a look at what this guy has done: sliding solar panels. It's on a Class A, but the same thing could be done on a B.
William......
Interesting - but looks like a mess and owners don't sound to happy with the job done by their installer. But I guess it is working for them as this video was posted in 2015 and they are still using it in their recent videos.
What is your guestimate of the cost difference between the Volta setup and the Delco 12V alternative?
I have no idea as I haven't priced or discussed that yet with Advanced RV. At Advanced Fest they talked about three options and labeled them good, better, best with increasing cost.
The good is what I have now which is the Delco alternator and Elite Power Solutions GBS LiFePo4 batteries.
The better is under development but had no installations yet as of early May. That was Lithiumwerks Valence LiFeMgPo4 batteries with the Delco alternator. Valence batteries are drop in batteries with corresponding group numbers as lead-acid in size. As for a lithiums you can't charge in freezing conditions but Valence batteries can be cold stored the same low temperature as AGMs. If that is what I go to I know I can get an 840ah array in a short Sprinter.
The best was the Volta 48v system and I think they install the 13kWh version.
__________________ Davydd
2021 Advanced RV 144 custom Sprinter
2015 Advanced RV Extended body Sprinter
2011 Great West Van Legend Sprinter
2005 Pleasure-way Plateau TS Sprinter
Have you calculated the weight of 1000w of glass solar panels? I am trying not to get a 3500 dually in a short 144 Sprinter mainly because the wheel wells take up a lot of floor space inside the van which wrecks what I am trying to achieve inside. Ideally a 2500 chassis would be optimal but I may have to go to a SuperSingle at 9900 GVWR. That's one reason why I may do away with solar altogether since I definite want the battery power which I already have and the second alternator delivers a guaranteed recharging.
The solar panel rule of thumb was an average of 30 amp hours per 100 watts of panel per day. Those residential panels claim 45% better. That's 43.5 amp hours x 10 = 435 amp hours. In practice I've found that rule of thumb was extremely optimistic (maybe on a clear day, unobstructed with the panels tracking perpendicular to the sun.)
But anyway, with a Delco second alternator I can charge 435 amp hours in battery replenishment in 1.5 hours of driving. I can go 3 days camping in one place on 435ah of battery discharge living as if I were plugged into shore power. It is inconceivable to me that would not drive in that time to charge my batteries and there is always idling as a backup resort. A Volta 48v system is even better in that it charges about half the time.
__________________ Davydd
2021 Advanced RV 144 custom Sprinter
2015 Advanced RV Extended body Sprinter
2011 Great West Van Legend Sprinter
2005 Pleasure-way Plateau TS Sprinter
My new van is coming with 200 watts of solar (and the Volta system). I only expect to use it to top off/maintain batteries while the van is not being used.
On my old van (Xplorer), I had 400 watts, which seems to me to be a sweet spot of getting a useful amount of recharging for moderate inverter use.
I'm with Davyyd on this one though. While it's tempting to get more panels to get more "free" energy, it's not worth the trade-offs when you get such massive charging from a 48v system.
1000 watts would require you to either build an ugly track on top of your van to hold the panels, or you'd end up giving up any roof vents, antennas and air conditioner unit. It also infers that you intend to use your van mostly to sit in one place. If you are going to use it more as a traditional camper, there are lot of other, bigger RV choices out there to do that. I like the mobility of a van, so I don't want to sit around for more than a couple days at a time. So by default, the bulk of my charging will come from running the engine.
On my big Class A, I have 1280 watts on the roof. Definitely overkill, but I can easily get 85 amps out of it. It takes up a tremendous amount of space on the roof.
Have you calculated the weight of 1000w of glass solar panels? I am trying not to get a 3500 dually in a short 144 Sprinter mainly because the wheel wells take up a lot of floor space inside the van which wrecks what I am trying to achieve inside. Ideally a 2500 chassis would be optimal but I may have to go to a SuperSingle at 9900 GVWR. That's one reason why I may do away with solar altogether since I definite want the battery power which I already have and the second alternator delivers a guaranteed recharging.
The solar panel rule of thumb was an average of 30 amp hours per 100 watts of panel per day. Those residential panels claim 45% better. That's 43.5 amp hours x 10 = 435 amp hours. In practice I've found that rule of thumb was extremely optimistic (maybe on a clear day, unobstructed with the panels tracking perpendicular to the sun.)
But anyway, with a Delco second alternator I can charge 435 amp hours in battery replenishment in 1.5 hours of driving. I can go 3 days camping in one place on 435ah of battery discharge living as if I were plugged into shore power. It is inconceivable to me that would not drive in that time to charge my batteries and there is always idling as a backup resort. A Volta 48v system is even better in that it charges about half the time.
Each of the SunPower panels I mentioned are 41 lbs. an array of three would be about 150 lbs. with mounting hardware and wiring. But then there is the weight of a roof rack to get them mounted high to clear roof vents an A/C unit if I add that.
I'd also like to avoid a dually Sprinter or Transit. Preferably using a 2500 model with GVWR of about 8,500 lbs., that means weight of all components will be critical.
My travel style often has me staying in same spot for several days and parking my van outside in driveway when I'm home. Right now my van with adequate solar can sit indefinitely with vent fan in auto mode and keep all batteries fully charged. I plan to have similar capability in my next van.
The Volta system looks very appealing and could reduce solar requirement. Right now I'm dreaming "pie in the sky" ideas. At some point I'll have to get down to physical and financial realities. I doubt I'd pull the trigger on a new van until 2020.
- - Mike
2012 Sprinter 3500 Extended converted B-Van by Airstream
See the picture, my 300W with the Maxxair fan and the Fiamma awning was very doable. 400W without a fan doable. 1000W doable but perhaps not practical.
If you would use similar mounting scheme to mine but with a smaller 80/20 30 series profile (I used a larger 15 profile) the weight of panels and crossbars would be for 300W = 52 lbs.; 600W = 96 lbs.; 1000W = 178 lbs. excluding brackets from Hein, which are not very heavy, and wiring.
Thanks George - very helpful drawings. I have four AM solar 100W panel on my van now. They are very efficient as I have then mounted a few inches above the roof on Rhino-Rack cross bars to clear the bath and tank vents. A 600W installation is likely more practical that trying to get to 1000W.
Those are the same panel I used on my Xplorer and was very happy with them. They often performed higher than their ratings.
Any scheme of more than 3 or 4 panels is going to require some kind of contraction on the roof to hold that many panels. Unsightly and obvious in my view.
I use crossbars from 8020 15 series (1.5”) profiles like on the picture. I think series 30 (30mm - 1.181in) would suffice. So, calculating the weight I assumed for N numbers of panel rows N+1 number of crossbars. I made my own brackets for crossbars, Hein sells them in more mass production tuned design. The brackets are designed to accommodate a Fiamma Awning.
That is a nice installation! I like that the panel does not sit higher than the bars. Winnebago is using a new bracket on their panels now, so they sit similarly and not higher than the bars.
Have you calculated the weight of 1000w of glass solar panels? I am trying not to get a 3500 dually in a short 144 Sprinter mainly because the wheel wells take up a lot of floor space inside the van which wrecks what I am trying to achieve inside. Ideally a 2500 chassis would be optimal but I may have to go to a SuperSingle at 9900 GVWR. That's one reason why I may do away with solar altogether since I definite want the battery power which I already have and the second alternator delivers a guaranteed recharging.
.... A Volta 48v system is even better in that it charges about half the time.
David,
Daimler Vans just posted the Body and Equipment Guidelines (BEG) for the new 2019 Sprinters. The new 2500 shorty high roof Sprinters will have a GVWR of 9,100 lbs and available with gas engine - good news. The 2500's have standard single wheels just like the 2500 Transits with a GVWR of 8,600 lbs. Copy of model variant pages attached.
I got the email on that and downloaded it. I've yet to look at it. I'm a little disappointed they haven't updated their drawings yet but I don't think it will be all that critical.
__________________ Davydd
2021 Advanced RV 144 custom Sprinter
2015 Advanced RV Extended body Sprinter
2011 Great West Van Legend Sprinter
2005 Pleasure-way Plateau TS Sprinter
It looks as if they maximized the roof solar gain. Did they achieve the 1000w goal?
Looks more like 600-700W to me. That custom Aluminess rack extends over the back end and looks taller than needed to clear the AC unit on the roof. The racks like this photo by Roambuilt also extend a bit over the front up to the radio antenna. Combine the two ideas and you have a lot of mounting space on short van roof and shade the roof as George mentioned.
1000 Watts of Solar on a Short Van?
Linear Mode
