I’ve been doing solar panel experiments in my flat for over a year now, starting with 2 75ah leisure batteries (got them on freecycle) and 2 20w panels in my south facing window. This solar panel project was good for some back up power but not good enough to try using on a daily basis. I should point out I rent a room in a 1st floor flat share and have no roof or ground where I can put solar panels where their output would be greater.
Earlier this year I upgraded my solar panel for my south facing window to a used yingi 220w panel I got for £85 from Bimble Solar. As you can see below it just fits in my big sash window.
I also brought 3 125ah batteries for £90 each and tied them together.
I tied in the output from the MPPT charge controller(brown and blue wires) to spread the charging cycle evenly across the 3 batteries. Below is my 1500w pure sine wave inverter and Tracer 20A MPPT charge controller.
Due to the bad positioning of the solar panel it’s output is nowhere near its max, even on a bright sunny day. Apart from not being angled to the sun it is also behind glass, not good but I simply have no where else to put it. Even so today I decided to power my Virgin Tivo box, 31 inch flat screen TV set to it’s maximum energy efficiency setting, DVD and broadband box from it. That should require about 70 watts an hour, a bit more if I’m watching a DVD. Of course I could just switch off the Tivo box while watching a DVD but it does take a long time to start up. It will all be switched off at the inverter when I’m not using it regardless but can my solar panel charge the batteries enough for the amount of TV I watch as I love all the Discovery, Animal Planet and Nat Geo channels. Well I guess time will tell.
In the mean time I’m thinking about ways to possibly increase the solar panels possible output despite the bad positioning. I’m also wondering if it will be more efficient any way during the late autumn, winter and early spring months when the sun is a lot lower in the sky.
51 watts was the best output I’ve got out of it on a sunny day in April. The Sun will still get higher in the sky yet so this might possibly drop. I might see if the land lord will let me put a mirror on my out side window sill to help the solar panel out a bit.