Overview
- Running a 100‑bulb LED string for six hours a day for a month costs roughly 14–15p, according to MoneySavingExpert and Martin Lewis.
- Incandescent strings cost about 1p per hour per 100 bulbs, which works out to around £1.80 for the same month‑long usage at six hours a day.
- MSE’s example assumes a 100‑bulb LED string using about 3 watts, and Birmingham Live notes costs depend on your tariff, citing an average 24.5p/kWh price cap.
- LEDs run cooler and are typically plastic, while glass incandescents waste most energy as heat, with Elesi reporting less than 5% converted to visible light.
- MSE points readers to a cost calculator and experts recommend plug‑in timers so lights switch off automatically to avoid unnecessary use.