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Author Topic: adding solar  (Read 8031 times)

richwill

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adding solar
« on: November 22, 2015, 09:41:47 PM »
i know it's a massive topic. But looking for some help/guidance/pointers etc.

i reckon i will go for as many panels as i can fit on the roof (300-400watts) and 2-4 110AH batteries. Looking for recommendations on panels (prices seem to be all over the place) and if anyone has any installation tips/videos (i've already got some from youtube) then they'd be really helpful too.

trying to get a good few days worth of energy (even in the winter) until i need to find somewhere to plug in. I really want to avoid a genny if i can get away with it.

cheers

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kryten

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Re: adding solar
« Reply #1 on: November 22, 2015, 11:01:43 PM »
Can we assume from your post that you will mainly be static? If you will be moving, even if not daily, then wiring your batteries to charge while your driving will mean you need fewer solar panels. Don't forget more panels equals more weight and more fuel used.

If you are concerned about running out of power then you should be looking at equipment that use less power, like led bulbs for lighting.

richwill

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Re: adding solar
« Reply #2 on: November 23, 2015, 04:44:59 PM »
Can we assume from your post that you will mainly be static? If you will be moving, even if not daily, then wiring your batteries to charge while your driving will mean you need fewer solar panels. Don't forget more panels equals more weight and more fuel used.

If you are concerned about running out of power then you should be looking at equipment that use less power, like led bulbs for lighting.

Hi Kryten,

i have no plans to be static. I don't know how much the normal engine running will keep the batteries charged. I will be looking in depth at energy management but want to ensure that i have enough to warm the van etc.

thanks for the response. All very much appreciated.
Life is a journey. Make the most of it.

scottdimelow

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Re: adding solar
« Reply #3 on: November 23, 2015, 08:07:22 PM »
Do you plan to have electric heaters? I wouldn't bother if you're using batteries, electric heaters sap power.

I'd use gas or wood for heat, leave the batteries for lights and electronics etc.

richwill

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Re: adding solar
« Reply #4 on: November 28, 2015, 01:55:59 PM »
electric would only be to power devices not for heating etc. Like i said, just looking for a decent (and reasonably priced) setup. Recommendations etc.

thanks again

Life is a journey. Make the most of it.

Ross

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Re: adding solar
« Reply #5 on: March 11, 2016, 12:16:24 AM »
Hey richwill, great question. There are a lot of details, but I'll take a shot at an overview.

You will need your solar panels, batteries, a solar charge controller, an inverter (if you want "household" voltage), and in my case, I also used a small breaker box to connect everything.

Solar panels: I have two Renogy 100-watt flexible panels adhered to my roof with Sikaflex, and then their perimeters sealed with Dicor sealant. Even though they are more expensive, I like the flexible panels because they bend to the curve of your roof and you can barely see or notice them. Very stealthy. The Renogy flexible panels are off the market and being redesigned right now, but several other brands have similar panels (I got mine on Amazon). $200 USD each

Batteries: I have 2 100-amp hour VMAX tanks batteries. They are highly rated and have functioned well, but I honestly can't tell you which brand is the best. My 2 batteries were $250 USD each.

Charge Controller: You will get a lot further with an MPPT controller rather than the cheaper PWM controllers. Both of them monitor incoming solar voltage and battery voltage and drop incoming voltage to what the battery needs in real-time, except the MPPT controllers do it about 30% more efficiently (they are also better in low-light conditions, which would help you out in winter). Mine is a Morningstar MPPT-45 which is way overkill (I liked the quality/data logging), but you could try one the Renogy MPPT 20-amp models to do the trick.

Inverter: I have a small 300-watt Pure Sine Inverter from Go Power. About $175 USD. You may already know, but this will boost your 12-volt DC battery power to 110 or 230 volt AC power. These lose about 15% of the power when converting, so I just use it for my desktop computer. Everything else is 12 volts for efficiency reasons. I wouldn't waste time with a Modified Sine inverter, as it will destroy your delicate electronics. Pure Sine will work for everything.

Breaker box: The most "controversial" part of my system, as it seems like overkill for a van. But once you see how many fuses and cutoff switches you need, this box makes everything really compact. Plus you can use DC solar breakers in it, which are a fuse and switch in one, helping to simplify things. I used the MidNite Solar MNDC-125 Mini DC Disconnect. About 175 USD. You could leave this out and just not have as many cutoff points, but you will still need a bit of wall space to mount switches and fuses. 

One last item. I used a small fuse block to power up my 12-volt branch circuits around the van. I used a 12-circuit fuse block from Blue Sea Systems (made for boats). It's really high quality. My batteries connect to this fuse block and that in turn powers up all of my 12-volt outlets and LED lights around the van.

As kryten said, you could use a battery isolator in your engine compartment to send power back to your batteries when your engine is running. I don't have one of these, but for about 80 USD, you could cut down on the number of solar panels. Like you though, I wanted to be able to park for weeks and not worry about driving around to keep my batteries charged. You could also use this in combo with your solar panels.

All together, my setup, with wire, connectors, etcetera, was about 1700-1800 USD. I could have cut this down with a cheaper charge controller, maybe to $1500 USD. This is by far the most expensive part of your conversion.

I hope this answers your question!

Ross

Vantwat

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Re: adding solar
« Reply #6 on: June 09, 2016, 07:11:59 PM »
I've got a question for the knowledgable out there,if I were to buy a 40w solar panel what could I feasibly run off of it ,baring in mind I only use my van for holidays etc? Could I run a cool box off it?

shinobidef

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Re: adding solar
« Reply #7 on: July 19, 2016, 09:43:58 AM »
To George: There are a lot of variables, including the direction of your panels (you want these solar south which might not always be possible depending on how you're parked up), how much sunlight per day, etc.

In theory, a 40w panel working at full capacity for 5 hours a day (with full sun) will put out 200W (in practice though, it's usually less than that).

To work out what you could realistically power, you'd need to think about whether you could store extra power in the battery (if you're in climates that have a lot of sun, for example), and whether you could bolster it via charging via the engine or mains. If you look at the sorts of things you want to run and do some calculations on the power usage, you can work out what panels and battery you'll need.

So suppose your coolbox is 12V and 50 watts. If you ran this for 8 hours a day, that is 8 hours x 50W = 400 Watt Hours. (to get Amp Hours, you divide this by the voltage (12V) so 400/12 = 33.3 Amp hours)

So based on a 40W panel putting out 200W a day, you could only power the coolbox for 4 hours daily if running purely off the panel (200W / 50W). But...you could potentially charge the coolbox while the engine is running off the car battery.

Coolboxes and fridges use far too much power for my planned set up so I'm hoping to get around this by to converting a chest freezer into a fridge (if you Google, there's some info on how to do this and why you'd do it).

There will be people on here who are a lot more experienced so please feel free to correct me if I'm wrong on the above!

BurningRanger

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Re: adding solar
« Reply #8 on: August 04, 2016, 12:36:49 AM »
You might want to also consider finding a way to tilt the solar panels to maximise sun exposure.