Solar Design Challenge

[Trebor English]

Your best option may be to modify your requirements and add a battery isolator 

I agree.  Keep the folding panel inside while driving.  That will avoid a lot of grief and you will miss out on very little charging.

 

[SoulRaven]

Your best option may be to modify your requirements and add a battery isolator to charge your house battery from your van's alternator (through the van battery).  The 2012 Sienna's alternator produces 150 amps to charge your van and house battery, FAR more than your 105-watt solar panel will ever produce on the roof as you go down the road.  This option will meet your requirement to not make any permanent changes to the van and you'll still have your panel to top-up the house battery charge when you re boondocking.

Yep.  I was looking for a way to avoid this, mostly because a) messing around with car functionality gives me the willies and b) solar/battery/electrical/usage information makes my head hurt and I am in the technical training business!

 

[SoulRaven]

> no gutters on my Sienna

Side rails are standard on the roof

Many Yakima foot styles fit them, just give etrailer.com a call.

No rails.  No gutters.  This Sienna has double sliding doors. I've already been to the Toyota dealership and they want $500 just for installing them, that doesn't include parts. 

http://www.toyotanation.com/forum/2...n-2011/374913-add-roof-rails-base-sienna.html

 

[tx2sturgis]

With due respect to Mr Tooley, I dont think I'd want a loose piece of glass up there. Possibly a thin piece of framed-in Plexiglas or Lexan sheeting. 

But then the panel could overheat in direct sun while you are parked.

For the 50 ah battery, if all you need to do is maintain it while driving, a simple fused power cord to the cigarette lighter plug will do that. 

Or a plug-and-play option that will actually CHARGE the battery is to buy an inexpensive, small, 50 to 100 watt inverter, the kind that plugs directly into the cigarette lighter plug, then buy a small Battery Tender, and plug that into the inverter. The Battery Tender has clips, or leads, just attach those to the battery.

Yes, its a 'roundabout' way of charging the battery, but no more so than plugging a laptop charger into an inverter.

 

[SoulRaven]

With due respect to Mr Tooley, I dont think I'd want a loose piece of glass up there. Possibly a thin piece of framed-in Plexiglas or Lexan sheeting. 

I was thinking Plexiglas also.

But then the panel could overheat in direct sun while you are parked.

For the 50 ah battery, if all you need to do is maintain it while driving, a simple fused power cord to the cigarette lighter plug will do that. 

Or a plug-and-play option that will actually CHARGE the battery is to buy an inexpensive, small, 50 to 100 watt inverter, the kind that plugs directly into the cigarette lighter plug, then buy a small Battery Tender, and plug that into the inverter. The Battery Tender has clips, or leads, just attach those to the battery.

This sounds like it might be the solution, at least until I expand the power setup. I will look for one.  I have a 450 watt inverter already.

Yes, its a 'roundabout' way of charging the battery, but no more so than plugging a laptop charger into an inverter.

 

[John61CT]

No rails.  No gutters. I've already been to the Toyota dealership and they want $500 just for installing them, that doesn't include parts. 

Super-cheap from a junkyard, will add to the resale value if that's your "no holes concern"

If the magnet idea, against paint rubbing there are soft rubber mats specifically designed for that.

 

[Spaceman Spiff]

With due respect to Mr Tooley, I dont think I'd want a loose piece of glass up there. Possibly a thin piece of framed-in Plexiglas or Lexan sheeting. 
But then the panel could overheat in direct sun while you are parked . . .

If you want to cover your panels, clear acrylic is preferable; but not the generic hardware store stuff unless you can afford to loose ~ 30% of your output.  You want a plastic made to transmit light in the 400nm to 1200nm spectrum:
http://www.totalplastics.com/products/650

If glass you need a low iron, tempered float glass with a non-reflective coating.  With window glass you will loose >25% output and it breaks into sharp shards.

In either case you will loose output, from reduced light hitting the panel and increased panel temperature from heat trapped under the clear cover.

 

[SoulRaven]

If you want to cover your panels, clear acrylic is preferable; but not the generic hardware store stuff unless you can afford to loose ~ 30% of your output.  You want a plastic made to transmit light in the 400nm to 1200nm spectrum:
http://www.totalplastics.com/products/650

If glass you need a low iron, tempered float glass with a non-reflective coating.  With window glass you will loose >25% output and it breaks into sharp shards.

In either case you will loose output, from reduced light hitting the panel and increased panel temperature from heat trapped under the clear cover.

I've gone with the battery charger, inverter solution, but I will keep this in mind for later.  Interestingly, the battery store where I got the battery charger was clueless about flexible panels even though they had hard solar panels all over the store.  Eyes got wide when I talked about the peel and stick versions.

 

[SoulRaven]

Super-cheap from a junkyard, will add to the resale value if that's your "no holes concern"

If the magnet idea, against paint rubbing there are soft rubber mats specifically designed for that.

The no holes concern is more about leaking from the job not properly done as well as resale value.  (That comes partly from having lived in the Pacific NW for the last 9 years. I no longer live there and am planning to move to a warmer, drier climate.)  And if I am going to spend money on labor to put holes in the roof, I would rather have a sunroof so I can have stealth ventilation with fan assist from the inside.

But really, I don't want to mess up a perfectly good minivan.  I want to mess up a much bigger, cheaper van once I have made the rounds in this thing. 

Thanks for the mat reminder.  I've ordered one magnet switch to experiment with. It should be here tomorrow.  Maybe I can keep some pots and pans on the roof as a mobile rain catchment system. 

 

[John61CT]

Mounting roof rack tracks to bare sheet metal *properly* is not rocket science, yes takes some research and brass cojones if you haven't done much other hands-on work. Details to follow if you want to go that route.

But an alternative, if you call or go to etrailer.com and tell them your model and year they will specify what models you can fit without any holes.