solar panels, batteries and inverters

[andy230]

Hello chaps, this old chestnut again!

Really this is one for Steve L, but I'll throw it open...

My garage is powered by a 110Ah 12v (BMW 7-series) battery.  This powers an inverter to get 240v out. 

I have 2 strip lights of 58w each, and an incandescent bulb of 40w.  Normal use is a single strip light (And my radio [4]).

So I get about 15h single light use (58w plus a bit extra for the inverterfrom the battery, but I can see it sedimenting and is obviously on the way out.  I drag this fecking massive battery upstairs to charge it once a week.  At night (cos the lecky's cheaper!)

Still I got the battery from the tip for nowt, so am not bothered about this!  One of my best blags, that one.

So in the not too distant future, I'm planning on a bank of solar panels (80w output, or something like that), and maybe 150Ah worth of batteries- 2x 75Ah or so.  I will get deep-cycle leisure batteries.

So my question- would anyone know what rating of panels to get??  would 80w be enough??  3h per night (max) powering a light and radio...   Any idea??  has anyone ever bought or fitted them?

I'd like a wind turbine to suppliment, but they're a bit pricey (tho apparently can be made...).

Anyway, cheers for now, hope someone can offer a bit of info.  I'm sure all the shops in london are putting their "green premium" on such a set up so that the "hampstead set" can feel like their doing their bit, while the rest of us can't afford to be so eco-friendly!

Don't get me started on the chipfat...

a
 

[Martin Churchill]

You could try www.greenshop.co.uk

They're in deepest rural Gloucestershire and the gaffer, Roger Budgeon, is an absolute environmental fanatic (I see him occasionally in the course of my work).

[Andy M]

Watch the ratings for solar panels, they seem to assume you live in Spain. 80W worth in Spain will produce about 40W in a UK summer and next to nothing at this time of year. I was looking at a website a few months back and will try and find the link, it gave a UK perspective.

Andy

[guest40]

Solar Panels are great... therin lies the problem. SOLAR... you need sunlight, I can send you some as we have too much.You may see it as early as tomorrow, or may be not ( its a UK thing).

[andy230]

Watch the ratings for solar panels, they seem to assume you live in Spain. 80W worth in Spain will produce about 40W in a UK summer and next to nothing at this time of year. I was looking at a website a few months back and will try and find the link, it gave a UK perspective.

Andy

Cheers andy.  I had assumed that maximum out put will almost never be reached, and don't mind giving the batteries an occaisional charge.  But a good point....

Martin- thanks for the link, will have a look

Kurt- here's the plan: I send you the cash, you buy the panels.  And we run a big long lead from your back yard in WA to mine in Finchley....  I Email you when the battery is fully charged, and all extra power is yours...



Still, if anyone has anymore info, I'd be pleaase to hear it...

Ta!

a

[Steve Lake]

Think it's all bin sed really........it really is 'lick yer finger an stick it in the air'  state of affairs
and it is the SOLAR aspect that screws us up, though to be fair, good panels will produce an output at low light levels, with that in mind, maybe go for over rating your system a bit, and rather than a big single battery, go for multiples in series/parallel with spares that you can introduce when needed.
I run an electric fence energiser off a pretty knackered 40ah car battery and a small 14" x 6" solar trickle charger been up the paddock for a few years and seems ok but of course the energiser consumption is very low.(but no doubt the sheep will realise one day, that with a series of dull days it might be worth trying a dash for freedom)
cheers

[guest40]

All jokes aside Andy, have you spoken to the yacht brigade. These guys are seriously into energy/low weight and portability. Some of their catalogues and magazines are gold mines to campers and energy misers. However, buying from chandlers leaves one gasping at some of the prices, and you may need to look at more conventional outlets once you get the info you want.
 I have a small setup of 2 x 6volt batteries in series hooked up to a depth sounder/ LED navlights and a solar trickle charger on my sea kayak. As the LEDs  run on either 6v or12v, I can extend the time for the lighting and with a cigarette lighter plug can illuminate a campsite with a flouro tube or 2  on 12v .
 If a battery dies I still have power to the LED's and its cheaper replacing a single 6 volt than a 12v battery. A dead battery is usually the result of only the death of a single cell.
Ive thought of a simple wind turbine by using a bicycle dynamo, which gives off 6 v @ 3watt. I could hook this up to a 2 x6 volt battery system in a parallel circuit.  Thats an upcoming projectfor the kayak.
  For your garage you could use an old car alternator, hooked up to a 12volt battery system. you will need 12 v avail from the battery to excite the coils otherwise it wont work. Alternators are good cos they can run in either direction, have built in regulators and diodes and  unlike a generator they produce 12v even at low rpm, whereas a generator needs to build up revs to deliver 12 v and then a regulator to max out at around 14v. You could possibly use an old pedestal fan blade set to drive it.

[guest111]

Have a look here for wind http://www.scoraigwind.com/ power, B n Q ones not much cop.

[guest27]

Hi There

Have a friend who avidly collects the cycle wheels with the hub dynamo - makes them in to lil windmills and gets some power - he seems happy.  Actually as dose his wife, their teenage boy thinks they are nuts mind.

Many many years ago - was at the Glastonbury Green fes - would have been the early 80's and the whole of the campsite was powered by small windgenerators made from car alternators - they had made changes to the alternators to make them work better at low revs (I think) - but have not been able to find out what it was they were doing mind.

So if anyone knows....

R