Garden Sized Solar system

phelimb

I'm looking to light up my garden so that the kids can kick around a ball outside during the winter and am looking at solar rather than wiring up lights to the house mains.
Quick research shows me I need a solar panel, battery, inverter and a bunch of other stuff.

Anybody got ideas on a complete solution? I'm OK with a DIY solution and don't mind getting my hands dirty

The area I have is probably the size of two tennis courts.

Appreciate any ideas.
Thanks,
PB

quentingargan

You will also need a charge controller to prevent overcharging the batteries. I would try to get 12V or 24V bulbs rather than an inverter and run straight off batteries. I have seen LED floodlights in farm shops which must ultimately run on DC voltage if you get rid of the transformer and use a DC DC converter instead.

There is a mismatch in using solar for winter lighting. You will have huge surpluses in summer and a dearth in winter. You will need to mount the solar panel at about 60 degrees to optimise for winter production.

The place to start is with seeing what bulbs are needed, and for how long. Work out your watt hours and then size your storage and panels accordingly. You can use RETSCREEN free online to calculate the output each month of a solar module at this latitude. Batteries need to be leisure deep discharge type and you should size them so that you never normally bring them to less than 50% of capacity.

Then size your charge controller in accordance with the max output of your solar panel. I would use an MPPT type for the added efficiency in winter and make sure that the panel voltage is well above battery voltage so that MPPT tracking can work.

freddyuk

Do you want to "floodlight" the area or just have enough light to see to play footy? How long will you need it on each week?
A 50 watt LED flood light will throw out considerable light so two or three of these would be sufficient although it is subjective. Or use lower wattage and site them around the area but you need to avoid dazzling people so one big light is to be avoided. I have tested the street light type LED units and they are amazing but too bright from one source at ground level.
Once you know how much light is suitable and for how long you can work out the rest.
eg. Estimate 100 watts (DC as Quentin says) which is on for say 2 hours 3 times per week. That is 600 watt hours. 80% efficiency will mean 720 watt hours is required. On a 12 volt system you will need 60 amp hours. You cannot run a battery down 100% so say 50% depth of discharge = 120 amp hours capacity.
You will need to recharge 60 amp hours each week. In winter you will need to do that over 7 days plus run the lights.
My suggestion is to use the LED/Battery option which will save you running cables and it will work very well but take the battery (batteries) back to the house and recharge them there. A decent deep cycle battery at 120ah will weigh 28-30kg. If you want longer times you will need two and a sack trolley. Best of both worlds from a cost standpoint.
I do not think solar is a cost effective option for a leisure project although it can be done you just need sufficient modules to replace your amp hours each week. If you do recharge from home then get a proper charger do not skimp on this as it needs to control the charging regime. (as per a charge controller off solar).
If you want the full solar kit come back with more info.

Capt'n Midnight

LED or CFL is the way to go.
CFL is still the cheapest way to get light but it means mains cable unless you can get an all in one fitting which won't be cheap.

White paint is cheap , ie. make the area as bright as possible to make best use of even ambient light. Remove obstructions, bright clothes, footwear and a glow in the dark ball if you can :pac:

BTW
A 12V garden light transformer would be a lot cheaper than solar and means you keep the high voltage inside the house and only take 12V into the garden.

quentingargan

A few years ago I got a batch of 24V CFL bulbs HERE. They seem to work well - have had them running for about 3 years.

However, I would imagine you are looking for more of a floodlight type of bulb, in which case the LED floodlights are more likely to work for you.

gman2k

I'd go down the LED route with these - 12v too!

I have a 220v version, great light off them, and at so low wattage, you won't be seeing a big elec bill.

quentingargan

gman2k wrote: »

I'd go down the LED route with these - 12v too!

I have a 220v version, great light off them, and at so low wattage, you won't be seeing a big elec bill.

Yes - I have a street light made up with these. Didn't realise they were available in single 12V units. They're the business alright.

freddyuk

The driver will be a 12/24v unit rather than 220v. Same thing other than that. Beware these are cheap and come direct from China so no back up if it fails. Also you may get a VAT bill and fees to add to the cost. It says warm white but details indicate cool white - go for cool white not warm white for outdoor use. You will need a few of these for this project or get 50watts.