Small scale solar PV system for gardens

MikeyMacbeth

Unfortunately I've had to eliminate any hope getting a full scale house system as :-
a) I'm pretty skint so have no money to invest in such, at least the thousands required for a full scale solar PV set-up (:eek:) and
b) the mid-terrace house I live in is ENE facing so it's dubious at these latitudes that there'd be much in the way of return from it!

However, I'm thinking of maybe a small-scale system with a small panel (~1sqm) in the garden, which would store power in a battery system to be kept indoors in my cellar (to avoid issues regarding waterproofing), off which it would be possible to run a small wired garden lighting system and maybe via an inverter a plug board for such things as mobile chargers etc.

In an ideal world the system would be extensible by adding additional panels/batteries etc.

Is anyone aware of either an off the shelf system such as described above or has anyone built such as a hobby project and could offer any tips on building such?

Keep in mind that the budget for this would be pretty low (see point a above ...:-) I'm fairly DIY handy so if a hobby project is the way forward I'd be looking to build from recyled components as far as possible - eg what does anyone think about cannabilising the pv bits old cheapo solar garden lights and combining into a larger composite panel (I'd guess these are pretty low efficiency)?

Mankysteve

Your unlikely to get anything meaningful back from panels from a load of solar lights. If you just want to play that ok. Coupled with a battery but you'll need a deep cycle battery. Just have a goole and read around nothing wrong with playing with things.

http://www.maplin.co.uk/search?criteria=Solar+panel+kit or checkout ebay

MikeyMacbeth

'Bout what I thought Mankysteve re the small panels - still I may have a go just for a play, see what I can get off it.

Those Maplins kits seem a lttle pricey just to play with (£62 for a 5W panel!) but Ebay may be the way to go - would be interesting if they quoted the efficiency figures). The 18W panel kit looks to be my starting point but I think it would take a while charging our mobiles and powering garden twinklies for it to give any ROI @ £184!

From what I've googled up so far I'll need:-

• PV Panel
• Wire (could reuse some old 3-core I've got lying around)
• Battery - "leisure/caravan type" is what I've seen often referred to on the web - do these need to be ventilated or are they sealed units? don't some batteries give off hydrogen? - will need to work out how much juice it can store versus the number and wattage of lights x expected hours of operation
• some kind of charger controller to control the charging of the battery - could this be a DIY built thing or would it be better to buy off the shelf
• some kind of stand for the panel to angle the panel to best capture the solar energy (I'm assuming solar PV's work most efficiently "face-on" to the sun?) - could build from bits of wood and an old camera tripod.

podcake

Hello, maybe I can be of some assistance.

first question is:

how many lights of what power (that is to say how much light do you want). Are you looking to read by this light or just look pretty (the lights that is).

2nd question:

how often do you want to use these lights?

nightly?
weekly?
once a blue moon?

once we know these things we can go a little further.

a panel providing 1 watt for 10 hours will light ten 1w lights for an hour.. etc (this is not quite true, I'll not go into details unless you would like but its all to do with the efficiency of the battery)

also don't even think about an inverter unless you have to. there is absolutely no need and it is simply a waste of time, money and energy. if the system is 12 and you need 5v just buy a regulator they are lossy, but you won;t notice the difference...

MikeyMacbeth

podcake wrote: »

how many lights of what power (that is to say how much light do you want). Are you looking to read by this light or just look pretty (the lights that is).

I guess I'm just looking at maybe 5 or 6 1W LEDS

podcake wrote: »

how often do you want to use these lights?

nightly

Although really I'm just playing with the idea/concept of seeing just how cheaply I can put together a totally low budget system that stores a days worth of power and might be capable of running a few lights overnight and maybe even charging a few mobile phones etc based on a day's worth of power. (hence mentioning the inverter).

I've played with the Solar Irradiance Calculator here to see just how much raw power is available at my latitude, obviously I need to deduct for the efficiency of the panels and as you mentioned the efficiency of the battery(s) and the fact that my (small) garden is facing ENE so will only get a proportion of that energy anyway.

Have you any suggestions for how to pick up 2nds /damaged panels? I've had a freecycle wanted ad running for a few days but no joy as yet ;-)