In part 1 of this article, we found that in most cases for a typical household, evacuated tube Solar Hot Water (SHW) has a quicker payback than PV. In part 2 we will more closely examine why this is the case. We’ll also see that combining both technologies can produce the best outcome for a household.
Use both SHW & PV for combined benefits
The most popular PV system size is now about 5kW, though 3kW systems are also popular. 1.5kW systems are no longer common. Consider that for about the same price as a 5kW system (~$7500), you could retrofit your hot water system and almost have enough change left over to buy a 1.5kW PV system. SunWiz’s analysis showed that evacuated tube SHW was often more financially favourable than PV, but in circumstances where heating hot water was cheap due to low-priced off-peak electricity or natural gas, a small PV system would have better financial outcome than a solar hot water system.