Example answer:
Average household off peak demand = Heating/cooling + hot water
+ other = 3 x 300 W = 900 W
Average household peak demand = 300W + 2 x 500W =1,300W
Average household demand = 0.25 x 900W + 0.75 x 1,300W =
1,000W
Total Australian households = 7.5M (Household size ~3
people)
Average total residential demand =7,500MW
Average total Australian demand = 7,500MW / 30% = 25GW
Total annual Australian usage = 25GW x 24h x 365 days = 25GW x
~9,000h = ~220,000GWh per annum