The company saw electricity consumption fall on Tuesday 24 March by 100 MWh (megawatt hours) following the introduction of remote working with schools and some businesses closing.
On Wednesday 25 March the figure was lower still as the lockdown was enforced.
The island’s average demand and peak demand dropped by 5MW (megawatt) over the period.
Head of generation at Guernsey Electricity Jon Sexton said that while the change is usage was understandable, it was remarkable.
'We have collected data for many years so can estimate the likely demand with a reasonable level of accuracy.
'This time it is different, as last Monday saw normal levels of electricity supplied and Tuesday showed marked differences with the majority of people working from home but a consistent supply over the day.
'On Wednesday, we noticed a much greater reduction as the closures and remote working were enforced.'
This same reduction was also seen on Thursday 26 and Friday 27 March.
Even with the much colder weather this week we continue to see consumption and demand below that expected for these conditions.
The company has also confirmed that the ‘switch-on’ period which peaks around 9am each morning had been flattened with Islanders staying home and businesses not opening to turn on lights, PCs and air conditioning.
Mr Sexton added: 'The weather has been sunny and warmer over the past 10 days which obviously reduces the need for electricity and now we are in British Summer Time the total figure will reduce further.
'Over the next couple of weeks we will see use of the power station reduce to test runs only as low carbon, renewable, imports cover all of the demand.'