what can you run on solar?

Julie798

Guest
Hi

I am totally new to camping, and I would like to try to understand the electric side of things, if one has a solar panel, what can they run, i have been told that you can run a small tv (7 inch) but not really anything else, so am I correct in thinking, if you dont buy a big generator, you cant run a microwave, kettle, slow cooker, sky dish with tv etc, we are hoping to camp on the aires etc, but I am getting conflicting advice, and I am not hard to confuse LOL.
 
Not going to go technical

Go to the "Search" button above and enter "Solar Panel" .There is a wealth of information.
 
Julie798 said:
Hi

I am totally new to camping, and I would like to try to understand the electric side of things, if one has a solar panel, what can they run, i have been told that you can run a small tv (7 inch) but not really anything else, so am I correct in thinking, if you dont buy a big generator, you cant run a microwave, kettle, slow cooker, sky dish with tv etc, we are hoping to camp on the aires etc, but I am getting conflicting advice, and I am not hard to confuse LOL.
Click to expand...

Hi. I agree with Shortcircuit that it's probably best to do a search first, and then come back with more specific questions, as it's difficult to fully answer without getting technical.

One point I would like to make, is that solar panals are used to charge your batteries, rather than power equipment directly, and the batteries used either direct to power 12V items or to power an inverter for a 240V supply.

From a personal point of view, that unless you regularly park up for several days at a time they are probably not worth fitting. Even the amount of charge supplied by a 80W panel (the smallest most seem to agree that is useful) in a day, will be matched by about 10 - 15 mins of charge supplied with the engine running.

Hope this helps a little, and ask away on anything you don't understand as I'm sure some one will try to answer.
 
solar panel

We have just p/x'd a van with 2 x 85watt panels which is quite a lot of energy, we found that they contributed very little to our needs, we tended to drive during the day so they were in and out of sunlight, the van alternator was doing the work anyway and by the time we were parked the sun was too low to work. Even though we live in Northern France they definitely didn't work in the Winter so unless you plan to park in the same place for days on end I would look at alternatives, I understand the new ones that follow the sun round are 5 times more efficient but only useful if parked up.
 
[Don't worry about being confused. What you need to worry about is the so-called experts who are often just as confused but charge you big money to provide you with an inadequate system]

It comes down to a couple of things - what sort of lifestyle you want and how much you want to pay to (try to) achieve that.
By lifestyle, I also mean whether you ever free camp and for how many days, how often you use powered sites, how many hours you drive, whether you would want to use a generator and of course what sort of electrical load you have installed. A few years ago a typical van had one light in the middle of the roof, maybe a reading light if it was a bit up-market - and very little else. Nowadays there are general and task lights installed everywhere, outside flood-lighting, heating and cooling systems, a couple of computers, a couple of water pumps, 220 Litre 24V compressor fridge, large entertainment systems, satellite systems, microwave ovens, washing machines and even bread-makers and espresso coffee machines. I haven't got the last two, but do have all the others and more, and in sunny Australia can use all this without concern for running out of power, and do it indefinitely. The only limitation is the amount of water and black and grey water we carry. My generator was last used in anger over 12 months ago while in Tasmania where is never seems to be able to make its mind up what season it is.

This doesn't come cheaply - 4 24V 165W (I think) solar panels and a 24V 520Ah AGB battery plus all the electronics that goes with it, but it does prove that solar is practical provided you have enough room and load capacity to fit everything. My batteries weigh nearly 400Kg so it's not a trivial consideration. We are full-timing so the criteria are way different to those applying for just one 2-week holiday plus the occasional weekend.

In the north of Europe (Norway, Sweden, ... - even in the summer, with panels laid flat on the roof you could expect maybe only 1/4 of the rated panel output so then a small generator might be more useful if you are going for any extended wild-camping in one spot.

The MH we are buying in Amsterdam won't have any solar fitted - but is being fitted with a 40kg refillable gas cylinder (hang the expense or the legality) - so my first job might be to find a quiet spot and stick a couple of panels to the roof. They may not provide all my requirements but from the stories told of shonky campground electrical hookups, I figure every night we can do without will be a bonus.
-----------------------

The tracking solar panels ARE 5 times more efficient than the same size panel mounted flat- BUT only if you do your test somewhere close to the Arctic circle. Otherwise they are just an expensive bit of poseur bling just begging to be wiped off the first time you forget to stow it.
 
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Hi Tony, about the gas cylinder, why do you worry about legality, ? is there a problem with underslung tanks, I had 2 on my old van which I only filled once! it was brilliant, the new van has gaslow refillable as there was no room on the chassis for fixed refillable, they were the best accessory ever, regards,rog
 
I had a 43 watt panel fitted at the end of last summer. It kept both batteries (engine and domestic) topped up during lay up, important to stop losing your alarm, It also seems to admirably top up the batteries during the day when stopping for days on end in the longer days of summer. What a lot of people forget is that it is light not sun that causes the photovoltaic's to work and that even winter sun will trickle a tiny charge. I love them, they are clean, silent, green, maintenance free, I only wish I had had a bigger one fitted. I certainly don't think running an engine for 15 minutes a day is clean, green or would win any friends near by.
 
solar

Thanks for the reply, we have just bought a van, it has a big solar panel on it, the people who owned it, said that was sufficient for all your needs, we are in the south of Spain, most of the time, but what I am trying to get to know is, can you plug in a normal appliance with a Inverter ( what ever that may be) and use a microwave or something similar, and not blow up the electrics LOL, I know people think that when you post, you probably haven't read anything, but I am reading until I am blue in the face, but I just don't understand the electric part of it all, maybe when I do it , it will be simple.
Theres nothing more deflating, than feeling like people think you are stupid, but its easy I know for those who already know it all, maybe I need a dummies book on motor homing LOL.:(
 
Microwave ovens are one of the most misunderstood loads when it comes to running an inverter.

You read the instructions and it says cooking power 850W so you figure a 1000W inverter will eat it. Trouble is the oven actually uses more like 1300Watts from the mains power. Add the inverter inefficiency and 1300W would require a battery draw of 120Amps at 12 V. A good 1000W inverter would supply that much power for say 5 minutes before tripping out.

For a single battery of say 150Ah rating, drawing this much current is likely to be way above the manufacturers maximum allowable rating and could damage the battery if the load continued for more than a few minutes. If you have two batteries wired in parallel, then the draw would be OK. Using it for a minute to heat up the wheatbix and milk would be reasonable but cooking a whole meal for an hour would bring even a 250Ah battery down to well below 50% charge.

Large inverters - and that really includes anything over 300watts - draw so much current at full load that they need to be properly installed with isolators and fuses -- and of course need a lot of battery capacity to drive them at full load for any length of time.

For the little loads like phone chargers and other rechargeable items, a 150Watt inverter would be OK and not need any special installation, but once you start talking microwaves, electric kettles, coffee-makers, hair dryers, toasters and the like, you move into a completely different area.

Then we need to talk about "fake" sinewave inverters (Quasi, square, etc) - cheap and nasty that mostly work but can cause damage to some appliances, and pure sinwave inverters that are 5 times the price but will run anything.

There are books on Motorhome electrics for dummies -- but they are really intended for those who supply and install the stuff.
 
"Hi Tony, about the gas cylinder, why do you worry about legality"

I don't -- weeelll, yes I do but mostly only when there are financial or moral or physically painful consequences for breaking the law.

In this case, provided the system is properly installed then having a permanently mounted bottle filled from an external nozzle is no different to the system in the LPG powered Ford I have back home -- so it is safe. Here there are thousands of autogas pumps but it is illegal to use them for anything other than gas-powered cars. All other bottles (9kg maximum size) are either exchanged or refilled by authorised attendants at a price about 3 times higher than the autogas.

Convenience and keeping my back in reasonable condition are the reasons for going for a refillable system (costing €500 for a 40kg system), but if I am going to have to drive all around to find an autogas bowser, or get chased off by some overzealous attendant, then the convenience factor is largely lost.
 
Julie, I should have given you this before

http://www.phrannie.org/invert.html

There are other more sophisticated sites around but this bloke has a no-nonsense style that is quite readable. Most is 5 years old and written for US but still well-current and applicable to your situation.

His other stuff is here
http://www.phrannie.org/phredex.html
and if you read and absorb all that is applicable to motorhoming in UK and Europe, you will be well qualified to come back here tomorrow and be the one giving the advice.

If you are holed up in a snow storm and getting bored go to the sources and resources link http://www.phrannie.org/sources.html and start reading. You may end up being even more bored but you will be knowledgeable and bored, which is better than being merely bored.
 
lenny said:
Hi Tony ,just to throw my hat in, :eek:,How about a solar panel to charge the battery-connected to an inverter- connected to a 240 volt battery charger-connected to the origional battery.:cool:
I suggested something similar recently(in jest:D), and no one said this was not feasable'

Regards..Lenny
Click to expand...

oh! c'mon now lenny
aren't you speaking about the dog,
that pulls the sled,
that pushes the dog,
that pulls the sled,
etc. etc.
:D :D :D sundown
 
sundown said:
oh! c'mon now lenny
aren't you speaking about the dog,
that pulls the sled,
that pushes the dog,
that pulls the sled,
etc. etc.
:D :D :D sundown
Click to expand...

Mmmm. That's got me thinking (the dog and the sled):rolleyes:,I'll sleep on that one then it's back to the drawing board in the morning.:D

Regards,,Lenny
 
Maybe they thought you meant solar panel charges engine battery which runs inverter which runs battery charger which charges the house battery.

Except for the solar panel part (which is more sensibly connected to the house battery), some innovators here are using this system to overcome the inherent undercharging of house batteries when being fed from the engine alternator.

There are lots of other equally good suggestions -
- mount a wind generator on top of the van so you get power for nothing to charge the batteries when you are driving along.
- Charging house batteries from the engine as you are driving is free energy.
- it costs nothing to drive with your headlights on [but legally required in some countries and recommended always, but certainly not free]
- always park under a street light so you generate power from your solar panel at night.

and then there are the unreasonable expectations-

I bought a 120Watt solar panel and the salesman assured me I would get 10 amps into my battery whenever the sun shone.
I have a 120Ah battery so I can run my 3- way fridge on 12V for a whole day.
If I can take 5 amps out of my battery for 20 hours, that means I can take 100 amps out for 1 hour.

and the myths -
It takes more power to make a solar panel than it can produce in a lifetime.
A battery lasts longer if you run it flat occasionally.
Batteries go flat faster if you put them on a concrete floor

etc etc.
 
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Thanks for clearing the GAS thing up Tony, there are no problems here in France or UK buing LPG on forecourts, but, I couldn't buy a French claw adaptor for love nor money in France, had to buy from UK mail order.
 
Just to add a new angle to this I have started a thread on magnetic motors have a look.
 
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