25 July 2011: This is the week in which I have started rebuilding the boxes, and I took the fronts off in the afternoon with the help of Matt, a neighbour.
I was able to give them a good clean, there had been white stains from old plumbing putty that have annoyed me for the last year and a half!
Increasing performance!: As it was a sunny day on Sunday, the impact of the black panels being naked in the bright Sun was an immediate increase in kilowatts. This is what I would expect on a sunny day.
Even though this removal of the front was at 4pm, there was enough sunshine for the Average for the day to be immediately boosted to 1.36kW whereas for previous week with the fronts on, the average has been about 0.94kW - a typical summer daily average. It makes me wish there was an easy way to have a major hinging method or similar that would boost the summer capture. I just don't see how this could be done with the strong wind forces that we occasionally get, and the difficult of a control system operated from a ladder.
My original thought had been to optimise for Winter and Equinox and to inhibit overheating in Summer. But now it is Summer, I am greedy and want more heat buried and a warmer ground temperature. This is the intention behind using the sloping face and the thinner PC skin and the larger volume.
Another reason for Polycarbonate: Although Chris Wood has suggested that I could do just as well with a flat plate solar panel or tubes, there is one thing that weighs on my mind. This gable wall over looks an agricultural field that is full of handy ROCKS! We have had a stone throwing incident about 2 years ago and one of the ideas behind using polycarbonate instead of toughened glass was the risk of them being target practice for teenage kids. Flat plate solar panels or arrays of tubes may be safe on the roof, but they are very risky on a wall.