[cmoski]

It's got nothing to do with the hemisphere.

Most likely the aircon is running less in winter so they don't use as much power. There is not much of a winter in the tropics.

[som]

Sorry should have been clearer, in winter there's no aircon (but also no heating, it's 20-25 deg c) and the pool pump runs approx 50%

[dostick]

It is winter right now.

[cmoski]

Yes, but it's nothing like winter further from the equator. It's a lovely time of year in that part of the world.