Solar panels on garden shed

I know nothing about how to set up a solar panel system.  I am wanting to get power to a garden workshop to run a light, and power a plug socket for using small electrical equipment eg. soldering iron, drill. What products would you suggest would be suitable and how would I set them up?

Hi Jennifer,

A solar panel system is extremely simple - a solar panel charges a 12 volt battery (usually through a regulator, a little circuit that prevents the panel overcharging the battery), and then you can power your appliances off the battery. Many appliances are designed to run directly off 12 volts - anything that plugs in a car cigarette lighter socket for example - but you can also use an inverter to convert the 12V from the battery into 240V to power standard household appliances.

In your case you would need:
1) a solar panel kit (which includes the regulator and wiring) such as our 40W kyocera solar panel kit.
2)  standard 'leisure' battery, available from any motoring store
3)  a 12V light to run directly from the battery (eg the Labcraft Trilite),
4) an inverter such as the 500W model, in order to run 240V appliances such as power tools. For bigger tools you might need a bigger inverter - the 1000W model would be more than adequate for most household power tools.

The 40W solar panel kit should be adequate for occasional domestic use in a shed. If you were using the system for more than an hour or so a day on average you might need a bigger panel.

Do hope that helps. I know quite a number of people who have done similar things on their garden shed - it is pretty easy to set such a system up.

Is an 80W panel sufficient for a motorhome?

Have just bought a motorhome and want solar panels suitable for long term living in van.  Would your 80w panel be sufficient, and what other items would I need ready for fitting this panel on my van?
Thanks - Andrea

Hi Andrea,

Whether 80W is sufficient depends entirely on what appliances you want to power! In the summer, for a few lights / water pump / radio etc it would be more than adequate; in the winter it might not be enough, especially if you also want to run things like a TV, laptop, or fridge.

Try our solar calculator to get an idea of what appliances you might be able to power.

If you buy the 85W solar panel kit it includes the regulator and all the wiring you need for fitting the panel. The only other thing you will need is some means of mounting it on the roof - it shouldn't be too hard to make up some suitable mounting brackets.

Solar for heat gun and lighting

Hi - I am going to start a business car window tinting in a standard basic garage; however I have no means of electric so I wonder if you have a solution. I need enough energy to power a normal light supply and also to be able to power a heat gun for 2-3 hours (not constant) a day. I do not have lots of money so would be looking for the cheapest solution. Thank you - Kieran

Hi Kieran,

It's possible - but it might not be all that cheap!

You can use our Solar panel calculator to work out how big a system you need. For example, a 40W light for 4 hours and a 1000W heat gun for 30mins per day would need about 516 watt-hours of electricity each day. 200 watts of solar panels would give you that much for most of the year, but probably still not enough in winter.

Some idea of the costs:

200W solar panels - about £800
regulator - £95
batteries - about £150
inverter - £148.

So it does add up!

regards, Andy

Running 240V appliances by solar power

I would like to build a device where a solar panel is connected to a UK standard plug socket, to power UK standard (240 volts I think) electrical appliances.  As far as I am aware I need a solar panel, a diode, a regulator, a battery, an inverter, and a plug socket.  The unit would be stand-alone, not connected to the national grid, but able to power standard 240v electrical appliances, e.g. electric kettles.

My questions are these.  Is this project possible (I assume it is, beacause it can be done on a larger scale by linking solar panels into the house mains electricity)?  How do I calculate the energy input output requirments of the components (can I use any components of different energy flow allowances with each other)?  Do the components have to be conected in a special way?

Thank you, Chris

Hi Chris,

Yes, the project you describe is certainly feasible, and in fact it's quite common to use solar power in this way to power 240V appliances where you don't have a national grid connection.

You can use our solar panel calculator to work out how much power your appliances will take, and how big a solar panel array would be needed to power them. The inverter size you need depends on the maximum power you need to draw from the system - so a laptop charger would be fine with a inverter of a couple of hundred watts; a kettle however would need a 2kW inverter at least.

You don't need a diode in the system if you have a regulator - the regulator stops the panel discharging at night.

regards,
Andy
Midsummer Energy

Solar powered cool box

Hello - I am looking for a solar panel which I can use with a cool box in our motor home. At present the box connects into the cigarette lighter. Is there a panel that has the facilty for plugging in such an item? Thank you - Tony

Hi Tony,

You could fit a cigarette lighter socket to any solar panel very easily, which would allow you to power your cool box directly. Something like the Spectra 20W panel might just be big enough to power a small cool box.

However, you should note that the voltage on a solar panel varies strongly depending on what appliances are attached to it and how much sun there is. Some appliances can accept a wide range of input voltages and would be fine with the variable voltage; others might not like a voltage of perhaps 18-20V applied to them! When you are running off a battery the voltage is very stable, normally between 12 and 14 volts.

Most cool boxes run on peltier cooling modules, which I am fairly certain would work fine when attached directly to a solar panel. However, I can't promise that it would work.

regards,
Andy
Midsummer Energy

Battery types and powering appliances directly

Hi, Could you please tell me in your opinion what is the best battery to use with solar power. Life span and cost are of paramount importance. Also, can you use solar power on very sunny days without charging batteries? Direct to a cooker? I am just learning/starting out to put solar on a caravan/motorhome. Thanks - George.

Hi George,

Standard leisure batteries available from any motoring store are absolutely fine for most purposes on caravans and motorhomes. As long as they are kept well charged they will have a lifespan of at least 5 years - it is batteries that are poorly charged that soon loose their capacity and need replacing.

'Sealed lead acid' or 'AGM' batteries will tolerate being discharged deeper than standard leisure batteries (and also never require topping up with water). But the extra expense is not worth it in most applications.

Cookers consume very large amounts of power - normally several thousand watts. You would need an enormous array of solar panels to power a cooker. It wouldn't really be very practical! In general you are much better storing the power from the panels in batteries rather than trying to use it directly.