harctan

Hello grayem. Perhaps the various Joule Thief type circuits can be of some help to you. For example this patent by Johh Bedini Patent US7990110 - Circuits and related methods for charging a battery - Google Patents shows a simple circuit that it is supposed to be able to charge a battery from a solar panel even if it is cloudy. This way it might be possible to bypass somewhat the cloudy UK weather. I'm still a novice myself so I can't tell you how well it will work for your situation but the circuit definately works, meaning it is possible to charge a 12V battery from a much lower voltage source (like a solar panel under cloudy skies). You can find the discussion on this project here: The SG Radiant Oscillator. Of course your goal is not to charge the battery but to light the bulb. This can also be achieved with these type of circuits like LaserSaber's Joule Ringer: http://www.energeticforum.com/renewa...le-ringer.html and his youtube channel: LaserSaber's channel - YouTube. It is supposed to be quite efficient although I can't verify it personaly as I haven't tried it yet. Perhaps someone more experienced than me can chip in. In conclusion the system I described is a battery lighting the bulb while it is being charged by the solar panel. Another thing that might interest you is that these circuits can be used even with empty batteries. Most batteries that end up in the trash usually have a lot more juice inside them but our appliances don't utilize it. So you could potentialy light your bulb from discarted batteries. Also these circuits can recharge non-rechargable batteries (although you probably shouldn't overdo it), thus squizing even more juice out of them before getting recycled. Maybe not renewable energy but definately reusable energy.