electrical engr.

You could use it to boil water and use the steam to turn a turbine and drive a generator.

This question gets asked all the time. Wassup? Google solar concentrators (192,000 hits). A desperate world wonders, "Where is Sparky now that we truly need him?"

<...A desperate world wonders, "Where is Sparky now that we truly need him?"...>

Quite.

A posse has been sent out to look, though Christchurch NZ is a fairly big city.

This is a repeat question?

Let us get it straight

- Solar heat density on earth is about 1.3 KW/sq mt - perpendicular to the ray. Now assuming you are going to run at supercritical boiler parameters then the efficiency will be about 40% so that is 0.5KW/m^2.

Now calculate the area of the magnifying glass (or parabolic reflector) that you need for collecting this heat, and then it has to follow the sun movement too along with the boiler tubes et al.

As against that the sun light has a density of 1 KW/m² and for that you need only photovoltaic (efficiency 12-25% except the 41% in lab).

That is the exact reason why the heating is limited to cooking and bath water where as the solar cells are for power gen.

Check this out...

There are many ways to <...generate electricity...>. What does the use of a <...magnifying glass...> have to do with any of them? Only asking, as it isn't clear what other equipment might be in the proposition at this stage.