The life of a solar panel

Here’s something you don’t see in the garden solar light adverts.. what you’re seeing in the frosty photo below is not untypical weather for the Northeast of England from November through February. When I  originally wrote this blog entry I’d had it up to here with cheap garden lights and was starting to move upmarket.

Last year we had several nights like the one in the photo below (rock solid ice in the morning) and the solar lights I blogged about last Christmas were and still are working a treat (more than can be said for most Poundland specials) and light up the garden only when movement is detected, running at a dim level at other times (and of course only when it is dark).

As you’ll see elsewhere I’ve left  such lights (and much prettier ones) running in Spain for the winter and I have two of this model here in the UK Northeast about to enter their second winter.

But there is knowledge here to be gained if you have a minute. Check out the photo at the TOP of this blog entry. The cheap lights I’d always bought from Poundland in the past after realising that B&Q were a little over the top on price – but then in Spain I discovered that we don’t do too badly here in the UK, they are WAY more expensive in Spain as my neighbours and I over there recently discovered.

There are many designs at £1 sterling to £1.50 sterling per lamp – most are complete rubbish – plastic on plastic. We bought some sets for Spain with a frosty white  plastic finish – the plastic deformed in the Spanish heat. Avoid.

Meanwhile back in the UK, I found rock-bottom cheap solar lights such as the “Tobago” lights shown here. Typical B&Q price in sterling £1.20+ each light,  Poundland I think went bust…. Spanish price is typically similar to B&Q or worse.

I’ve had many of this (Tobago and similar, usually unbranded) design over the years (see top photo of a single light). From eBay I just bought 20 (2 sets of 10 lights) at 72 pence per light – had I bought 30 they would have been 68 pence each including free postage – unbelievably cheap.

Of course none of the cheap lights I  mention here last more than a couploe of years but here are some tips: Get lights with stainless bodies and clear lenses, glass if you can but they are usually plastic – which will not last anywhere near as long as glass.

Before I tackle problems, here’s a thought about operation. Small solar lights are basically designed to a price so there are limits.. especially in the UK where sunshine is at a premium. Try to give them as much sunlight as possible – and later in the day is better than earlier in the day even if that means less than ideal positioning. Usually these lights turn on BEFORE you really need them on, so if they’ve had no decent light since lunchtime they don’t last long before fading. Don’t believe the bull about not needing direct sunlight, they WILL give some output in cloud or shade but MUCH, MUCH less than when fully covered in direct sunlight.

Here’s a list of things which will go wrong in order of likelihood:

Firstly (before considering opening up) it is always worth cleaning the solar cell area and giving the lamp 5 minutes in the sun before digging deeper.

Battery connectors corrode (the lamp will not charge if this is the case, so clean the connectors THEN expose to the sun or a bright light for a few minutes BEFORE expecting to see output. Often this will FIX the light. After putting the battery back in place, consider WD40 on EVERYTHING.

The switch if fitted may have rusted connections. If so, and after checking the battery connection and refitting the battery, consider WD40 on everything.

Check that the battery wiring and solar panel wiring has not dropped off, resolder and cover everything in WD40.

The battery COULD (unlikely) be permanently dead but for the cost of these, is that worth progressing?

If the LED is badly corroded or the circuit is badly corroded you are likely to have a permanently useless lamp.

Some advise plastic sealant – this will fail just as the plastic did and is likely to make more mess than it is worth. I tried nail varnish on the corners of the solar cells. Ultimately failed every time – bright sun eventually kills most materials.