If only driving around 20-30 minutes a week am I better buying dc charger or 300-600 watt more solar on hood and sides of van?

[Gueyog8a7]

My lifestyle is more like that of a static caravan and no I don't want to live in a caravan! I explored that idea before getting a van and decided van was the way because I would easily be able to move it when I want. Also since I am in a small van (transit connect) I am able to drive down the smaller country roads that even normal vans often are note suited for. This is good for me in my search for land in rural areas.

As I was thinking about it last night I suddenly realized there is still much unused van real estate for solar on the sides and bonnet of the van!

Sure they will not be placed optimally through the whole day but as the sun moves they will won't they for certain hours and I know from being parked in shade all the time behind my mum's house that the existing panels on the roof still get some solar even when not in direct sun.

This is where flexible panels come into their own because I could mount them on these parts where glass ones would be unfeasible with just some sealant. The ones one the roof I have already I did with sealant and the bond seems super.

Certainly this will well and truly do away with the stealth factor but since my goals have changed now that doesn't seem to matter. I originally planned around stealth parking in towns and villages but now I just want to stay at mothers and drive out to look for land to buy in rural places so stealth doesn't seem to matter now really.

The dc charger costs several hundred pounds, similar to what 3-4 more panels would cost. I had my eye on a 40 amp one from sterling however it seems a waste to pay that much for something I will barely use. If it is 40a and only driving 30 minutes a week on average that means I would get how much for that short journey? Is it 20a? That is estimating max current for the whole journey which would probably be less right?

That being said that may even be more than what I would get with the extra solar for the whole week???

Sure it would be nice to have that as a backup option but I want to avoid having to do forced drives if I can help it so another solution would be preferable.

For 2 x 100 what panels I only get probably 0.4 average per hour. I was as high as 2.5 amps when I was out driving all day the other day (rare exception) so they certainly have potential but it was clear and sunny.

I guess something in between for most days if parked out from behind the building into direct line of the sun.

I just checked and with my tracer bn 4215 I could put 3 more panels on it with the total at 520 but would 5 of these panels be ok in series? Not sure about what to look for in that regard and if there are limits to how many you can run in series. I think I read there are but forgot what the limits are.

This link looks like it is promising! The chart does not show below 50% efficacy no matter the orientation.

 

[rodrick]

200 watts of solar for one hour per week would give you the same power so I would vote for the panels and due to the fact you are stationary mainly I would go ground deployed to get best results

 

[Gueyog8a7]

200 watts of solar for one hour per week would give you the same power so I would vote for the panels and due to the fact you are stationary mainly I would go ground deployed to get best results

200 watts for one hour per week? You mean at peak output? The whole issue is I am getting a fraction of stated 200 due to uk winter as mentioned in the number above. Often as low as 3-5w sometimes up to 22w. More if out from behind the house in direct sunlight but all very fluctuating so have to plan for worst averages.

Probably better to look at a week's output or total to date. I will look at the mppt stats for that.

Are there limits to how many I can have in series or only the max wattage of the mppt?

I can get 3 more panels if the latter is the case.

Na I want them stuck to the van even if less efficient. First I don't want to be constantly deploying and undeploying. Second not faesible to deploy when parked on my mothers drive having a bunch of panels lying on the tarmac. Even though I don't plan to be here longer term same applies unless I am on my own land by then at which point space constraints will not be an issue and also I will be free to burn wood to heat probably which is the main reason I want the paltry electrics to power diesel heater. Third nowhere to store them in my van when undeployed anyway.

Sticking to the van makes more sense to me even if a performance hit is taken.

 

[rodrick]

Are there limits to how many I can have in series or only the max wattage of the mppt?

Your scc should have a max voltage specs in the manual when you figure the max voltage of your panels use the voc number for this calculation and also remember you have to adjust for lower temperatures the panel voltage will increase over the voc number so you need to leave some room

 

[Gueyog8a7]

Your scc should have a max voltage specs in the manual when you figure the max voltage of your panels use the voc number for this calculation and also remember you have to adjust for lower temperatures the panel voltage will increase over the voc number so you need to leave some room

As I am usually behind the house out of direct sunlight I drove to the last bit of unblocked light where it was clear sun, though granted the end of the day so maybe that in not representative. I only got an increase from 0.1 amps to 0.4. That means even if I got 3x the panels on there it would still be sweet F all .

Though I have to look at what I have gathered this month on mt50 to get better tangible data. Again though that is in shade so no good data on clear line.

I worked out to run the diesel heater for 2 hours including expensive startup will take around 4 amps - 2 amps for the startup at 14 amp/6 to give approx ten minutes then 1 amp per hour once it settles into passive electronic requirements.

Going from memory I get about 20 watts on a full day of solar behind the house. That is 1.6 amps per day. Still far short of the 4 amps!

I could buy the charger at 40a to give me +/- 20a per week additional for my 30 minute food shop drive.

Maybe like 5 more panels and also the charger would just about cover it but then I start to wonder if it is even worth it since it would cost like 600 or more pounds. I could probably heat myself somehow much cheaper than that for the couple months until it gets warmer and lighter again.

As my long term goal is to get land I am wondering if the above will be relevant to my then. I would like to have some land by next winter at which point I would be spoilt for choice in terms of space and what I could use. So debating whether to save my money unless whatever I got would be transferable then as the electric is only going to increase day by day going forward. I suppose in this case solar would still be worth as I would make use of the solar when having land. The charger not so much,