12 volt lighting

[muddyjames]

I hope someone can help me with this idea I have.

I like the idea of making my house run off solar pannels but looking into pannels for the roof and making 240volt looks very expensive and ages to get money back off. SO my 2nd idea

Have 2-3 caravan leisure batteries in the shed, solar pannels on shed roof (south facing garden) and wire up 12volt (possibly LED) lights and so all my lighting would come from the batteries. Obviously pc etc would still run off 240volts from national grid.

How easy would this idea be to set up and run? I think it would cost alot less than 240volt solar pannels.

2 110amp hour caravan batteries (approx £70 each) £140
2 solar pannels £200
12volt lights (stab in the dark guess) £200. Can get some reading spots for some areas.
Wire about £100?

So looking at spending about £500 in total to set my house up. I think £500 would be way over estimating. Also it would mean I could take it to other houses if I move and I dont drill loads of holes to install lights. Im thinking of mounting them in boxes and screwing them to walls ceiling etc.

There must be a technician boff out there who can tell me I'm mad and dont even go there!!!

[blackbob]

you could get a power converter and run the 240 off the battery system so you can run low ampage stuff like the pc
so you only need mains for the kettle cooker ect
also you would need to run new wirers into the house for lights ect  big job
also get a wind generator to keep the system topped up at night and for the winter
easy to set up but time consuming

[DaveS]

If you had enough panels and batteries should be possible, use inverters for 240v stuff.
You can get 12v TV freeview boxes etc for caravans/campers no problem.

I assume you have gas or solid fuel for cooking heating!
Sounds like a good idea.

[Damonski]

Go for it :)

Ive been playing with alternators as a wind generator to provide 12v power to a wireless repeater to increase the distance to the other barn on the other side of the farm.

12v lighting I have pondered over numerous times and I serioulsy think its very much a reality and not a dream.

Definatley go for it!  12v rocks :)

[Mudlark]

I think you're going to have problems - big problems :lol:


I ran a carnival float a few years ago and used 12 volt lighting on it - it worked but we had to overcome a lot of problems to do it.


Firstly I assume you'll be using halogen lights so amp rating will be:

20 watt = 2 amps

35 watt = 3 amps

50 watt = 4 amps

all approximate

say you run lights that use 60 amps in a house you have to get that 60 amps to the lights - start thinking around 10 - 15 mm welding type cable ok you can thin it out as you go down to a single light but at 12 volts you have to take in voltage drop as well remember as the voltage drops on a length of wire so the amperage goes up and heat is produced.


Our first attempt at lighting was to string two bare (insulated each end) steel wires along the length of the float and twist each halogen light to these wires as each light progressed down the wire it got dimmer - while we were thinking about it we left them on to test the time it took the battery to flatten before the battery flattened though we were treated to a firework display and the steel wire burst into flames :shock:

We ended up with 7 x 35 watt lights strung on two lengths of 2.5mm wire in six banks we also had about 20 x 20 watt lights on a roundabout (driven by a 12 volt windscreen wiper motor the lights being fed by four 6mm wires.

To power all this we had 4 batteries with a 500cc subaru engine driving four 100amp alternators to keep the lighting going, if the alternators failed the batteries died within minutes (but they weren't good batteries )

All I can say is at the end of the day it was fun designing it and getting it to work but we had a lot of problems.


You'll have to work out the output of the panels and make sure they will replace what the lights take out of the batteries each night.

Possibly work during the summer months  :lol:  :lol:


Any Questions??

[M19 ROO]

would l.e.d. lights not solve al ot of high amperage issues... they are very bright these days! would light up a house no trouble lol

[Mudlark]

would l.e.d. lights not solve al ot of high amperage issues... they are very bright these days! would light up a house no trouble lol

Good point enough of them might do it if you want soft general lighting

[muddyjames]

I would use caravan 12v lights and strip lights.I know a 75amp hour battery last a week in a caravan if ur careful.

I am thinking my house would be a big caravan type of wiring.

I have gas for cooking and heating etc. lights r my biggest power usage.

I just dont know what size cables to use etc etc. I dont want to overload wires etc. I really think it is do-able.

[mmgemini]

James.
I'll tell you better after my next trip BUT
I think you'll need at pay a lot of money for solar panels.

Have a look at www.merlinequipment.com.
I know what I paid for one panel and regulator.

Remember also at this time of year you might only get an hour of enough light per day to charge the batteries !!

Thinking cap on.
Fridge and freezer will take a LOT.

I still like the idea though.I think it's doable despite the problems.

[Mudlark]

James.

Remember also at this time of year you might only get an hour of enough light per day to charge the batteries !!

I think I've read somewhere that the solar panels used to keep batteries charged on a boat aren't working properly.


It's a subject that I've discussed many times without coming to any real output

And James if you're using caravan lighting that's diffferent from what I did and have always discussed - you'll get away with lighter cables, solar panels backed up with wind alternators might help as well.

I know we did a show once with a small foot square solar panel driving a pump to pump water through a 8' x 4' sheet of double wall plastic sheet (conservatory roof stuff) continuous pumping all day - when the sun was out heated around 60 gallons of water to hot enough no to touch!!!! - Free hot water :lol:  :lol:  :lol: Problem is it doesn't work when you need it in the winter for central heating as soon as a cloud went across the sun the panel died :(  :(

[Llanigraham]

I know it's a Canal based forum, but have a look here:
http://www.canalworld.net/forums/index.php?act=idx
There have been some threads about panels etc here.

[Evilgoat]

Am looking at a proposal to change the daytime lights in our flats to solar. Landlord is already putting a grey water supply in so hes well of for it.

The panel arent cheap and they do have a finite life. But if you go with strip lighting and low voltage tungsten where you can get away with it you should be laughing. Its also possible to convert full sive 240V tubes to 12V.

Biggest thing is going to be weeks like this one has been, grey and nasty, You'd be well advised to have the ability to switch over to mains or top the charge up from mains. Surplus switch-mode should be fairly easy to come by.

If your system can provide the power then why not switch all the things powered by wall-wart style power supplies too? I have circuits to replace these with 12V switching regulators.

[muddyzook]

Intresting thread  :!:

A few years ago I rented a house that had pay as you go meters, and they where knackered they kept tripping out and the landlord whould do nothing about it so I got around this by fitting a 2nd hand computer UPS I picked up from work to one of the circuits in the house (don't ask to much about the legalities of this now days) result was when the power was OK it charged the batteries and when it tripped everything plugged into that circuit remained powered whilst I went a kicked the meter.

The UPS has 12volt battery's and an inverter inside it, so if you could find someway of charging the batterys not via the mains, you should be able to run it continualy. and then if your external 12 volt source failed, you could go back to the internal circuits without any major hassle by plugging the UPS back in, thus removing the need to change any cable going to 12 volt.

Try EBAY for a UPS the batterys inside these things are the small alarm style ones, but can't see why you could not upgrade them to caravan batterys with a bit of research.

[Evilgoat]

12V to 240V is a really inefficient way of doing it. Lot of power lost as heat in the invertor stage and mechanical noise (yes Im serious). In a UPS you just fit a bigger battery but in a domestic situation you are worried about every last watt.

Also this setup IS illegal :)

[muddyzook]

Had a feeling it was going to be illegal, but remember it's only illegal if you get caught  :D only joking.

What are the rules on doing something along these line for say a garage or shed ? that has no connection to the grid at the moment, if it is a simple as changing the batterys for bigger one's to make them last longer then this could get around my shed power problem. Getting hold of a big UPS should not be a problem as we are having all of ours changed at work.

[Evilgoat]

Had a feeling it was going to be illegal, but remember it's only illegal if you get caught  :D only joking.

What are the rules on doing something along these line for say a garage or shed ? that has no connection to the grid at the moment, if it is a simple as changing the batterys for bigger one's to make them last longer then this could get around my shed power problem. Getting hold of a big UPS should not be a problem as we are having all of ours changed at work.

Shed at my Ex's was totally off-grid, including the TFT monitor and think client I used for looking up stuff on the net when one of my projects invariably got stuck. One whapping solar panel and two lesuire batteries.

You can use a UPS like that no problem at all but you still need to use mains to charge without a panel. you might be better off with a panel and invertor and even then, take a look see what needs to run off 240. Also remeber power tools = BIG invertor.

[muddyjames]

This is really interesting to read all the replies. Keep em coming.

What is a UPS? Only UPS I know is the parcel delivery guys in brown vans!!!

I am mainly wanting to start out on 12volt lighting. Keep the 240volt system as it is so if the batteries die I can still see!!

I have thought about a battery charger to top batteries up if they do go flat but to be honest as I am at work from dark to dark (7am-3-4pm) and it is day light then the batteries will have all day to top up again. If they do go totaly flat due to lack of light I will put a car charger on them over night. Not sure on if I still gain by that or not but hopefully I wouldnt need to!!

Only 240volt things that are constantly going is fridge / freezer and pc for a few hours at night. You maybe thinking now if thats all I am running then light bulbs wont take much to run but I am a tight arse and like to do my small bit to the environment to counter act the bad I do like driving and use gas to make hot water etc etc.

I dont use a kettle as I cant stand tea, coffee, dont use tv as I dont have 1 so the mega power useage items I dont use.

The other thing is if I have 12 lights everywhere in a power cut I will be laughing :lol:

I am no electrician so need to keep everything to a minimum in the trickyness stakes!!!

A 12volt wind generator maybe usefull to help the pannels charge the batteries up.

In a caravan and boat you can get very bright ceiling lights these days that run on 12volt. I only have a small 2 bed house so wont take loads of work to do.

I still want to keep my 240lights just incase the batteries go dead!

[MuddyMike]

If lighting is your biggest use for electricity then why not just switch to low energy light bulbs? I saw them for sale in Focus DIY last week at only a quid each.

Mike

[muddyjames]

To charge a battery of say 120 amp hours what kind of wattage solar pannel would I need?

I have found a few intersting sites along with someones link above.

for example This 15watt one

Would that charge a half flat 120amp hour battery and if yes how long would it take on a cloudy day roughly as most of the time it is cloudy in the uk!!!

With 2 120amp hour batteries and 2 solar pannels so 1 pannel charging each battery, would they do the job?

Would I wire the batteries up in series or parrallel? Im guessing parrallel.

[muddyjames]

If lighting is your biggest use for electricity then why not just switch to low energy light bulbs? I saw them for sale in Focus DIY last week at only a quid each.

Mike

I have those light bulbs but I got mine from Ikea. Totaly free lighting sounds even better though

[tomarse]

This is really interesting to read all the replies. Keep em coming.

What is a UPS? Only UPS I know is the parcel delivery guys in brown vans!!!s

a UPS is an uniterruptable power supply. basically a 12v battery and an inverter. charges off the mains all the time then as soon as the mains fails stuff runs off the battery instead. used to keep computers servers up all the time.

I fancy fitting 12v lighting in my house but havent got round to it yet. I have some old ups's to cannibalise and am considering just using the inverter in it to leave the 240 lighting in but charge it via something else during the day.

i am also building a wind generator. more efficient than solar and cost nothing to build. I made mk1 but need to refine my prop design for mk2.

have you also noticed that you can buy plug through power testers that tell you how much juice stuff uses. those power saving light bulbs are only 11w each, so it is almost less hassle just to use those everywhere!