A heat pump hot water system stores your cheap daytime solar as hot water, cuts the biggest single appliance load in the house, and currently attracts up to $2,030 in Victorian rebates.
See my numbersHot water is roughly a quarter of a typical Victorian energy bill. A heat pump makes the same hot water with a fraction of the electricity, and when it runs in solar hours the energy is close to free. With gas hot water ending its era in Victoria, this is usually the first and easiest step off gas.
If your gas unit is near end of life, replacing it with a heat pump is usually the highest-return move on the whole electrification list. The Exam will tell you where it sits in your staged plan.