Solar hot water system: effective life and depreciation rate

15 years, as the Commissioner of Taxation determines it for "Solar" under "Hot water systems (excluding piping)" in the residential property operators' table of the Income Tax Assessment (Effective Life of Depreciating Assets) Determination 2025, which most schedules use (an owner may estimate its own instead, section 40-105). Seven of the other 36 items here share it, among them an evaporative cooler and a rainwater tank.

13.33% a year under diminishing value (200% ÷ 15), taken from what is left of the value: $533 of the $3,996 it costs installed new in the first full year, $301 in the fifth. Or 6.67% a year under prime cost (100% ÷ 15), taken from the cost: $266 in each of the first five. An item first held before 10 May 2006 takes 150% ÷ 15 under diminishing value.

Generally not, for an individual, a self-managed super fund or most trusts and partnerships that bought an established property at or after 7.30 pm on 9 May 2017 (section 40-27; the 2017 rules set out who it reaches and the exceptions). Such plant is still valued, at what it costs new in the year the property is bought less its age and condition: for a solar hot water system 8 years old in good condition, about $1,865 of the $3,996 new in 2026, a value whose decline can make a capital gain or loss when it is sold or scrapped. For a solar hot water system bought new for the property while it is let, and never used while it was the owner's home, deductions start on the day of installation.

About $3,996 installed new in 2026, from our cost database, and about $2,960 in 2010. The other items here nearest it in price are an evaporative cooler (about $4,485, with a 15-year life) and carpet (about $4,545, with an 8-year life).