The approach was first to tabulate in a spreadsheet and plot the total electricity consumption per year taken from electricity bills.
Then for every possible appliance and light, a plug-in electricity monitor was used to measure the power in Watts and kilowatts (where constant) or the energy in kilowatt-hours per use cycle (where the power varied).
These were multiplied by estimates of the power-on time and number of cycles per day and hence per year and, together with the dates of installation and (where applicable) withdrawal, tabulated in another spreadsheet.
These itemized electricity consumptions per year were totalled and plotted to compare with those from the electricity bills, and the estimated quantities adjusted to improve the comparison.
The table of the appliances and lights was sorted on the individual annual electricity consumptions, and plotted, to identify those items which offered the greatest scope for saving electricity.
Possible changes of usage, such as reduced power-on times, and choosing between existing appliances by annual electricity consumptions, were considered as costing little or nothing.
Possible replacement appliances and lights were considered, with their initial cost and estimated annual electricity consumptions taken from energy labels etc, to determine the electricity and cost savings, and hence the payback times.
For all appliances and lights, the Best Practice annual electricity consumptions have fallen substantially in recent years, and the future Achievable values are even lower, according to the applicable scientific laws.
Saving electricity for appliances and lighting costs less, and saves carbon emissions, much quicker than building or replacing electricity supply facilities.