How much energy does my fridge use?

By monitoring the energy used by household appliances I can learn how to reduce my energy use here.

A household refrigerator can use most energy because it is on 24/7.

The bumps in the graph below show the times the fridge compressor - the engine which keeps the air in it cool -  turns on and off at night and during late night times when most appliances are off.  The bumps show, for example:

  • at 5.20 am the fridge compressor turns on; energy use goes up to 319 watts from 233 watts
  • at 535 am the fridge compressor is still around 318 watts
  • at 5.45 the compressor turns off and the power use drops to 233 watts

The data tells me the compressor ran for 15 minutes and for that time used  another 85 watts in addition to the 'base load' or typical minimum energy being used by the house at any one time, which is around 233 watts.

  • Screenshot showing energy use at Sydney's Sustainable House, 10 April 2018

• Screenshot showing energy use at Sydney's Sustainable House, 10 April 2018

The compressor bump tells me the additional energy is used during these midnight hours (when the house is cooler) every 30 minutes or so. 

This data source is from the household solar and battery system and has proven unreliable throughout the period since installation, March 2015.  I'll do another blog later about the inaccuracy of the data systems and very poor performance of the solar and battery system designed, provided and installed by two firms I strongly recommend against using, Australia Wide Solar and Alpha-ess; detailed initial analysis of the installation and systems is here.  With three years of data it's clear the systems are giving me less than 46% of the promised amount of power and are fundamentally inadequate, or 'lemons' in design, installation and performance.  They're being fully replaced.

The more reliable data source is from a product I also use to monitor household energy use and is a combination of technology from Wattwatchers and Solar Analytics

This screenshot below shows data from these products.

 •  The data on my energy use - notice the energy use 'bumps" up when the fridge turns on

The data on my energy use - notice the energy use 'bumps" up when the fridge turns on

Solutions for cooling a fridge and reducing your energy use are here.