solar powered lights?

sculptor

Hi Folks, I'm looking for a solar powered lighting system for a cow shed (it's across the road from the house). Something that would power a few 150watt bulbs for an hour a day, the roof is south facing and it needs to be fairly cheap. I've heard of systems for powering electric fences but they seem overpriced. Any ideas?
Jim

2 stroke

Wait a few years and what you're looking for might be available. For the moment you should consider more efficient bulbs, this will reduce the number of panels and storage batteries needed.

muffler

sculptor wrote: »

Hi Folks, I'm looking for a solar powered lighting system for a cow shed (it's across the road from the house). Something that would power a few 150watt bulbs for an hour a day, the roof is south facing and it needs to be fairly cheap. I've heard of systems for powering electric fences but they seem overpriced. Any ideas?
Jim

So this cow shed would be directly across the road from your Victorian terraced house which is located in Dublin according to this post.
Locked until sculptor PMs me with an explanation and it had better be good or it will be lights out (Christ i just love the puns )

muffler

Clarification sought and received.

Thread opened again.

reilig

sculptor wrote: »

Hi Folks, I'm looking for a solar powered lighting system for a cow shed (it's across the road from the house). Something that would power a few 150watt bulbs for an hour a day, the roof is south facing and it needs to be fairly cheap. I've heard of systems for powering electric fences but they seem overpriced. Any ideas?
Jim

Hi, its a good idea in theory and I'd love to do something similar myself but can't imagine the size of a solar panel you would need to power even the lowest watt light bulb. Some suggestions that you could consider would be to install a skylight into the shed which would be a cheap and reliable option. There are some fantastic skylights out there these days, ones that can send light through tubes onto the exact area that you want to light up, and you can just close them up when you don't want light.

Another option would be wind power. Saw some fab small turbines on ebay not too long ago which don't require planning and can be diy erected on the equivalent of a scaffolding pole. They run efficiently on the calmest of days and turn off automatically when the wind gets too fast. Power from them can be stored in batteries. If I'm not mistaken, the cheapest of them is under €1000 - show me how much of a solar panel you would get for that.

Just do a search on ebay, there are several suppliers out there.

Just my twopence worth, hope it helps!!

Daniel

Whatever option you go for, consider using low energy bulbs.

Simplest option may be just to get a couple of deep discharge batteries and use a standard charger to charge them at home plus a standard inverter (or use low voltage lamps) and swap them over every few days.

As cost is a major consideration this may be the cheapest option.

edit: no chance of running a cable over there?

2 stroke

The other option would be to cover that shed with solar panels and run a cable back to power the house.

sinnerboy

2 stroke wrote: »

The other option would be to cover that shed with solar panels and run a cable back to power the house.

.... if the shed is close to the main building . The run from the panels to the hot water tank should be kept as short as possible

Mellor

sinnerboy wrote: »

.... if the shed is close to the main building . The run from the panels to the hot water tank should be kept as short as possible

I assume we the panels in question are PhotoVoltaic solar panels, not the HW kind :)

2 stroke

I was talking about PV panels but if you're talking about water heating and have a large cowshed covered with panels the length of pipe run is less relevant. However, you would have enough hot water for a small factory.

sinnerboy

Mellor wrote: »

I assume we the panels in question are PhotoVoltaic solar panels, not the HW kind :)

Doh !

sinnerboy

2 stroke wrote: »

I was talking about PV panels but if you're talking about water heating and have a large cowshed covered with panels the length of pipe run is less relevant. However, you would have enough hot water for a small factory.

or power showers for the cows

sculptor

Thanks for all your humoooourous and enlightened replys. But there must be a simple system out there, when you see the traffic warning lights, parking ticket meters all powered by P.V. all I'm looking for is a P.V. panel a battery and a few lights. Maybe I'll buy them seperate and hope it works.

2 stroke

You're looking to power A few 150 watt bulbs for 1 hour a day, fairly cheaply, Its not possible fairly cheaply.
Now if you consider a bank of maybe ten 1 watt 12 volt led replacing each 150 watt bulb, then you can do something fairly cheaply. even run them from cigarette lighter socket on the tractor.

Mellor

The main probably is that "traffic warning lights, parking ticket meters" run on DC current from the PV panels.

FL or CFL lights do not run on DC, you will require an AC invertor to run these lights from DC. Struictly speaking it is technically possibably to run these on DC but the current needs to be high to strike an arc and the lamp polarity has to be inverted to prevent mercury collecting at one end.

The invertor make the set up expensive and more complicated. Use a light that runs from DC such as LED clusters. These would be far far better than FLs, as they use less power and they run on DC easily (they infact require changes for AC).

sculptor

2stroke I cant find the cigarette lighter on my'78 Massey 135 must have fell off with the door in '95.
Thanks for the input, a group of lights would be better for working under, less shadows for the pookies to hide in.
I seen some led cluster bulbs for sale on ebay but with the lack of information its hard to figureout how much light they give out, there again I wont be doin heart surgery and hopefully no caeserians.
What goes between the panel and the battery? I presume you need something to cut it out when it is fully charged.
Buying P.V. products is a minefield. On the web you can see the same product for vastly different prices. Has anybody bought anthing?
I might trawl the internet at the weekend, products for trailer homes etc. lots of stuff for boats but it's probably over speced.

Doddy

I would first consider reducing the light wattage and use 12 volt dc bulbs, the expensive thing about solar electric power is the panels and the batteries. If you are using 240 volts you will need an inverter converting 12 volts to 240 the larger these are the more expensive.
Battery wise you will want leisure batteries with large amp hour capacity not tractor starter batteries.
For a good 200 watt solar panel will set you back around 600 euro
most solar panels come fitted with a voltage regulator at around 17.5 volts ideal for a 12 volt battery bank. However this does not stop the batteries charging when fully charged therefore you will need a regulator these also get expensive the larger the amperage.

Hope this helps.

2 stroke

Sculpter, I can't help you with the 135, we didn't have the delux model with doors.
Seriously though, I'm only experimenting myself, this led light technology is evolving and I expect to see them becoming more common place next year. Keep your eye on the Green Issues forum.

sculptor

So I'll try not to rake over old coals.
There is a company in England offering a kit 50watt pv panel, charge controller, 300w pure sinewave inverter for 600euro is this a bit of over kill?
They have a 25w panel for 200 and 13w fluorescent 342mm x 34 x49 for 40euro.
What do I need?

2 stroke

Hi Doddy, welcome to boards. I hope thats not a typo. Where can I get good 200 watt pv panels for €600?

Doddy

To help with the search for lights lumen or Luminance is the unit to measure lights intensity. Don't price the panels up in rip off Ireland, Germany has been subsidizing solar power for some time now so you are not looking at 1000 euro a pop.

sculptor

Keep forgetting we live in a cellar (mushrooms) not on an island.

Doddy

Good luck on your hunt for an hour a day I would sugest a 50 watt pannel 12 volt battery and low voltage spot light. Maplin have a few ready to go kits.

Doddy

They have a 25w panel for 200 and 13w fluorescent 342mm x 34 x49 for 40euro.

Get 2 flouresent tubes and 50w pannel perfect.

sculptor

if you ever need advice on stone, art or organic farming (you meet all sorts here) let me know.

Mellor

how big is the shed?
I'd be a little concerned that 2 x 12w wouldn't be enough. Depending on the efficacy of the lights, they might not have a high enough output. As Doddy said, luminance is the measure of this and lumens are the units.

2 stroke

2 x 12w bulbs is certainly a big comedown from a few 150 watt bulbs.

sculptor

Do fluorescent tubes give more lights per watt ?
Found a German site on ebay solearworld24.com they seem reasonable.
As Albert used to say " it's a big hall " 6m X 9m but I only have to light the front.

Mellor

sculptor wrote: »

Do fluorescent tubes give more lights per watt ?
Found a German site on ebay solearworld24.com they seem reasonable.
As Albert used to say " it's a big hall " 6m X 9m but I only have to light the front.

Yeah, they give more light per watt than incandesant bulbs, but less per watt than some leds or other ultra-low energy lamps.

for reference, the lumens per watt figure is measured as the efficacy of a lamp. The effacy of a lamp is a good indictor of effiency of the lamp. Efficacy approaching 100 would be considered good. Standard bulb would be about 13, halogens about 25, CFLs about 50-60, FLs about 50 to 110 depending on type and LEDs are c.30 - 150 (the huge range is misleading here are not all LEDs would be suitable for domestic lighting)
Max efficacy btw is 683, but this is for an ideal monochromatic light source at 100% effiency.

Mellor

Mellor wrote: »

Max efficacy btw is 683, but this is for an ideal monochromatic light source at 100% effiency.

Be horrible to use an a luminant, especially if the cattle are colour blind to it:D