In Summer months you can expect most of your hot water supply to come from the sun (about half the year).

But the technology works well in cooler climates too, and you will get significant heat even on cooler days that have light cloud cover, so expect solar gain throughout the year.

While evacuated tube technology works efficiently even on very cold sunny days, keep in mind that the solar intensity is 5 times less in Winter than in Summer.

For this reason, it is best to optimise your system for Winter conditions by tilting the solar tubes to a slope of 45 degrees. By doing this you will get maximum efficiency in Winter whilst avoiding excessive heat wastage in Summer.

Low cost stainless steel frames are available if your roof is not steep enough.

(In Summer, you can expect to get 25kWh of heat per day from a 30tube array, whereas in July you can expect 5kWh per day on average. Even in the winter, it is possible to preheat the water to 40C or more if the sun comes out. The booster will then take it up to your desired temperature.)