Quick answer: standby power
- The law: “Power consumption of equipment in any off-mode condition shall not exceed 0,50 W.” With a display showing, the limit is 1.00 W.1
- A device drawing 0.50 W all year costs £1.15; 1.00 W costs £2.31.
- Some devices draw more when they keep working in the background, such as charging over USB.
- Last checked: 28 October 2026.
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Real standby figures
Published figures for named products, a year left in that state.
| Device and state | Power | A year |
|---|---|---|
| PS5, rest mode powering USB | 4.65 W | £10.72 |
| PS5, rest mode | 0.30 W | 69.2p |
| MacBook Air M4, off | 0.16 W | 36.9p |
| BT Smart Hub 2, off | 0.036 W | 8.3p |
Who these figures cover
Costs use the Ofgem price cap average for England, Scotland and Wales, 26.32p per kWh by Direct Debit, 1 October to 31 December 2026. Your region and tariff change it.5
HMRC: “The temporary zero rate applies from 1 October 2026 to 30 June 2027.” The Budget on 28 October 2026 extended it from 31 March (announced; the legislation is due in early 2027). Gas stays at 5% VAT.6 In Northern Ireland, use the unit rate on your bill.