Sample Photovoltaic SetupJune 21st, 2012
In response to a request for help I had these views
I mentioned a number of options to alleviate your dependence on the generator. Given a spend of £600 you could buy 250W panel, 120Ah battery and a MTTP controller and peripherals. The ones I mentioned would be very good quality. You could save 100 or 2 maybe but quality would drop.
The cheapest option is just to have more batteries so that when you do run the generator you will be storing more for the next day. However after you gave me the details of the battery charger, at 10A max. it wouldn't charge much more with another battery or two and you would still have to run it for some hours. You may be able to get similar batteries to that you have for £60 (70Ah)
My latest view is that you would be better off with a single solar panel of 100W. This would give a 8A charge to your battery every hour of good sunlight, compared to 10Amax from the generator.
I have contacted Wind and Sun in Hereford and they have a new 100W panel from India, the cost is £126 including VAT and Carriage. It has a general junction box so standard cable can be used to connect it.
A more substantial option is to buy two such panels, two more batteries and a controller and you would be unlikely to have to use the generator, but that would cost another £350. This would give you 200W input, per good sunshine hour, 210Ah battery.
The outcome as of 20th June 2015 is to buy a single 100W panel as in the penultimate paragraph above. I am encouraging the user to connect it themselves and monitor the battery charge with a pre existing voltmeter. The panel can be manually adjusted to receive maximum radiance or alternatively reduced to ensure the battery doesn't overchange. Once a voltage of 14.5 has been sustained for two hours the maximum should be reduced to 14.