These 'vampire' devices are typically those such as televisions, games consoles or microwaves that passively use electricity even when not in active use.
In its research, British Gas claims that televisions are the most expensive item to leave on standby, costing around £24.61 annually, followed by set top boxes (£23.10 annually) and internet routers (£18.89 annually).
Other devices such as washing machines, printers or mobile chargers were found to cost less than £5 on a yearly basis when left on standby.
However, Twitter users have questioned some of British Gas’ calculations, especially following a 2013 ruling from the EU mandating that devices including TVs and microwaves use no more than 0.5 Watts or less per hour while in standby mode.