A solar panel connected to a multimeter and a leisure battery
Portable solar power solutions
John Adams |
Tuesday, 26th October 2010
One of the beauties of renewable energy should be that you can take it with you anywhere. John Adams tries out some portable solar power products
The Solar Mate 1 consist of a 5W rigid solar panel, a 9W 12volt long life bulb, bulb holder, wall switch, cables fuses, etc. Everything you need to set up a mini off grid lighting system in a stable, shed or polytunnel, except a 35-70Ah, 12volt leisure battery (I got mine from www.alpha-batteries.co.uk).
The system is easy to rig up, though I would have liked a bit more wire, and the resulting light is very good. The low energy bulb has an output equivalent to a 45W mains one but it seems a lot brighter than that when surrounded by darkness (see above). The makers claim you can enjoy up to 7 hours light every night and while I am a bit sceptical about that, it certainly does charge well even in low light conditions and should be able to provide enough light to do routine tasks every evening. If you need more than this there are bigger SolarMate kits (see www.green-shopping.co.uk). Being based on a leisure battery these kits can of course provide many hours of light or power as a one off in an emergency.
Mains inverters
With winter power cuts in mind, I tried using the solar charged battery as an emergency power source. By attaching a 300W mains inverter (www.maplin.co.uk), I was able to get my combi-boiler gas central heating to run. I estimate that with the heat turned right up and the boiler fired up in bursts of an hour or so as required I could keep warm for a couple of days with a bit of solar charging in between (Note: do not try this unless you are confident about all the safety aspects involved). Alternatively it would for instance, power a low energy lamp, laptop computer and modem for many hours.
Another way of providing emergency backup and general portable power is the PowerPlus Eco-powerstation (also called an Elephant) which is a neat unit that resembles one of those jump-start kits garages use. Indeed it can be used to do this if required. There is a lot more to this unit than that though, it has a 14000 LUX led flashlight, and from its 12Ah battery can output 12V, 5V USB, and 230V AC via a built-in 100w mains inverter. It can be charged via a mains adapter, a 12V power supply, its hand cranked dynamo or by a suitable solar panel like the PowerPlus Albatross.
Flexible solar panel
The Albatross flexible solar panel had no trouble charging it despite the awful weather and the rather loose adaptor supplied for the purpose. In tests it was quite amazing to see an 11W mains uplighter running from this portable powerpack and had it been a real powercut would have been very comforting (it should be able to keep this up for 6-7 hours). As well as lights it can power a wide range of mains appliances providing they pull less than 100 watts (unfortunately this rules out the gas central heating trick) and charge your mobile phone etc., via the USB. Talking of phones, if your house phone relies on electricity to work, it won’t in a power cut but the Eco-powerstation could resolve that.
These two products were never intended to compete but the Power Plus is a portable unit (you could even carry it around to keep your portable tool batteries charged up or take it camping), has more charging methods and is also an ideal stand-by unit for powercuts, etc. The SolarMate is a fixed unit which should provide useful light on a day to day basis. It does however use a much larger battery which could usefully be borrowed in the event of a power outage. John Adams
Reviewed items are available from Green Shopping www.green-shopping.co.uk
Small off grid solar
Several people have asked about using Eco-powerstation and Albatross in caravans and other full time applications. While they would do this, it is not really what they are designed for, which is more of an emergency backup role. A much better solution is to use a leisure battery and an inverter (see above for suppliers) with either an Albatross panel to charge it (if you need portability for security) or a Solar Mate fixed panel. The larger sized ones are particularly good and all three sizes can be found at
http://www.green-shopping.co.uk/solar-mate-one.html
Please do get a multi-meter so you can check on the power in your battery and if you don't feel competent about wiring your own system safely do find someone to set it up for you.