Hot Water Systems

The following calculations use an average consumption of 200 litres of hot water per day from a 50L system for the average family of 2 adults and 2 children. An average rise in temperature for hot water in Alice Springs of 45°C.

Calculations are based on a 50L 3.6 kW electric hot water system.

Electric hot water systems operate using a thermostat which keeps the hot water topped up to a preset temperature. The thermostat turns the hot water system element on and off through out the day according to ambient conditions.

An electric hot water system relying on the thermostat alone for control will consume:

12.57kWh per Day x 15.01c per kWh = $1.88 per day

In addition to thermostatic control you can introduce another method that will reduce your electricity consumption and inturn incur savings. This method involves turning the how water system off and then only back on for short periods of time when hot water is required. It is usually sufficient to only turn the hot water system on for 1 hour per day. This switching can be achieved manually by turning the hot water on and off at your switchboard or with a timer installed by a certified electrician.

The cost of only turning the hot water system on for one hour per day is:

3.6 kWh per hour (max) x 15.01c per kWh = 54.03c per hour (max)

By only turning the hot water system on for one hour a day the potential savings are:

$1.76 - $0.50 = $1.34

The time that the hot water system is turned on can be experimented with to achieve results that suit the individual best.

COOLmob
Power and Water sponsor COOLmob to provide subsidised home energy audits and water audits. For more information about reducing energy and water consumption and to organise a $10 audit visit www.coolmob.org for Darwin or www.dkacoolmob.org for Alice Springs and Tennant Creek.