12V lights for catering trailer

I need a 12v replacement for my catering trailer which is usually lit by a 1.5m fluorescent mains light. Will an LED strip give me enough light? Tony.

Hi Tony,

You would need quite a lot of LED lights to give you the same brightness. You might be better (and a lot cheaper) going for 12V fluorescents such as the Trilite 24W. Depending on the size of the trailer you might need several units to give you the same brightness as your original light. If you can find the power of your current light, in watts (it's likely to be on a sticker on it somewhere), you will need about the same wattage in 12V lights to give the same light output.

Andy
Midsummer Energy

Sizing a solar panel for lighting a stable block

I am running two Lumina 18w lights in my stables powered from one 85amp leisure battery.  I am charging from the mains when the battery needs recharging.  Can you please advise what size & type of solar panel, regulator etc I would need to keep the battery charged.  I also run an electric fence from a second 85 amp leisure battery which is situated behind the stables.  Could I put the two batteries together, use one solar panel and run both applications? Regards, Wendy

Hi Wendy,

It all depends how many hours a day you use the lights! If we assume 1 hour a day every day, that's 18 watts x 2 lights x 1 hour, or 36 watt-hours per day that you need to generate from the panels. In summer you could generate that much power from a very small panel - even a 10W panel (such as perhaps the Spectra 10W panel, with a Sunguard regulator).

In the winter, you would need something bigger - but I think a 40W panel should be sufficient even in the depths of winter. In that case you would be best going for the 40W solar panel kit, which includes a 40W Kyocera panel and a Sunguard regulator, and all the wiring you need.

If you use the lights for more than one hour a day on average, you would need a bigger panel in proportion. If less than one hour, you can go smaller with your panel.

Yes, it would make a lot of sense to put the two batteries together and run both the electric fence and the lights from the one bank. Electric fences don't use much power - I think you would be able to run both the fence and the lights from a 40W panel. Very easy to do - you just wire the two batteries in parallel, with the two positive terminals joined by a lead, and the two negative terminals joined with another lead.

best wishes, Andy, Midsummer Energy

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

Integrating solar into existing power systems

I am currently looking into the feasibility of all forms of renewables as a supplement to existing power supplies. I have had a number of amorphous PV panels on test for six months with a quite small load. Any thoughts on how to integrate a small scale system for lighting(using LED lamps) would be appreciated ! Simon.

Hi Simon,

When you mention 'existing power supplies' do you mean mains electricity or a battery powered system? The two are fundamentally different. To integrate solar panels into a battery system is trivial - simply connect the panels into the system via a regulator.

For mains supplies, integrating is harder. You can get inverters to convert the DC electricity from the panels into 240VAC to connect to the national grid, but they are not cheap, and it's not DIY wiring! For a small scale system of less than a few hundred watts it's not worth the effort and the cost. Besides, LED lights are usually low voltage DC types, so converting from DC to AC and back again is a bit pointless.

An alternative is to run the lights from a switch that can be set to either 1) a battery bank that is charged by solar panels or 2) a mains-powered 12V power supply. Most of the time you can run the lights off your batteries, but when they begin to get low, simply switch over to the mains supply. It wouldn't be terribly hard to create a circuit to do it automatically when the voltage began to drop.

A friend of mine runs the lighting in his kitchen from such a setup, and it has worked very well for him.