First step: check where the sun's likely to be over the course of the year.

Positions and heights of potential shading obstacles were measured with this Blue Peter-style clinometer.

This metal merchant in Rawalpindi supplied us with copper pipe and aluminium sheet.

Building anything from wood must be preceded by cutting your own planks out of the big chunk of timber you've bought.

Simple frame complete. Note the complete lack of any safety features on the scary power tools.

A few construction materials.

Copper tubing cut to size and ready for assembly.

We took all of our copper tubes out to a chap in the bazaar with an oxy-acetylene torch, then brought it back to leak test it.
We had to take it back once or twice...

There seems to be an inverse relationship between the quality of the brazing job and the beauty of the metal surface afterwards.

Aluminium sheet was battered into fins that fit over the tubes using a big sledgehammer.

The aluminium we were able to get hold of was a bit thick, which made cutting it all up with only a pair of tin snips very hard work indeed.

The thickness of the sheet also meant staples were useless (even if we'd had a staple gun),
so many holes were drilled and many nuts and bolts called into action.

Panel painted and placed inside its frame lined with thermopore insulation.

Double glazing being fitted. We only broke one small corner.

The very first "let's just see if this works" test. It took 5 of us to lift the panel out to the orchard.

We have hot water!

Largely irrelevant angle-grinding.

A couple of old door frames were pressed into service as legs.

Propped up at 50 degrees to catch more of the winter light.

Taking temperature readings.

81°C!