01/06/2014

Work on the solar panel is complete. The glass has been installed, and I made a frame from some scrap pieces of wood to hold the glass in place. The scrap wood already had a 5mm rebate on one edge, which as luck would have it, is exactly the thickness of the glass. Some closed-cell foam tape provides the necessary expansion joint, and the entire frame was waterproofed with silicone sealer around the edges.

Perhaps this week we’ll be able to put it on the roof! I’ve constructed a pulley using a plank of wood and a plastic fishing-line spool with a steel bolt through it. A rope will lead from the base of this pulley, over the ridge line, into the garden, where it will be anchored with a stout metal bar like a large tent-peg. Another rope will be attached to the solar panel, and go around the pulley. The solar panel itself will be resting on two aluminium ladders; and the theory is that by pulling on the other end of the rope, the panel will be dragged up the ladders until it drops into the steel frame which is already fixed to the roof itself.

However, we’re going to need some extra manpower to carry the solar panel out of the construction area (the barn) to the ladders, so we’ll probably need to ask T&M for some assistance. I used vehicle glass instead of polycarbonate sheet because we already had several large panes of vehicle glass, which were removed from a long-gone combine harvester. Polycarbonate sheeting would have added to the cost tremendously. I estimate the entire panel weighs some 60kg. The glass itself weighs around 36kg. But it’s not the weight which is the issue; the panel needs to be moved in such a way that it does not twist and break the glass! Unfortinately it would not have been practical to install the glass once the panel was on the roof.

Now I need to start fabricating the control panel. This will display the various temperatures in the thermal store, and control the operation of the radiator circuit and the solar panel pump.

Some unscheduled electrical work also took place today. Since the installation of the washing machine, we have found that it sometimes causes the electricity to trip. We have a three-phase supply, and balancing each of the three phases to run single-phase equipment is a bit of a black art. The washing machine causes the power to trip because it is on the same phase as the borehole pump. If the pressure vessel is full when the machine starts, there’s no problem; but if the borehole pump starts up whilst the washing machine is working, the load on that phase of the supply is too much, so the power trips off.

I have now moved the washing machine circuit to a different phase rail; we’ll see if that helps.

Wildlife diary: Unfortunately (for the coypu, that is), it had not moved on to other premises. It just didn’t like potatoes. An apple, on the other hand, proved irresistible. It was humanely despatched, but that now means I have another job to do: skinning the animal. LSS has found a recipe for coypu stew.