Sizing your system.
What we know.
By rule of thumb, a regular household needs 20 litres of hot water per day for general use, plus 50 litres per person a day.
So a 3-person household will use roughly 170 litres per day of hot water.
So…
A 2 kW array (about 5 panels) will more than do this in summer in NSW.
“Overclocking” your system.
We match your inverter to your hot water element size, but the Hot PV™ inverters can take more panels than their rating, without needing to be up-sized. This is called “overclocking”.
We use this capability to improve the performance of your array in spring, autumn and winter. For example, adding another 2 panels will improve your spring and autumn water heating energy by about 2kWh each day.
And for the 3-person household example, in winter an additional 4 or 5 panels would bring the family close to 100% winter solar water heating capability - on good winter sun days.
So you should only need to boost when there is a prolonged lack of sun!