Example Electricity Cost Savings - Lighting

The examples below have been chosen to represent normal use and to demonstrate some of the savings possible.

Lighting

Light		Costs	Saving
Standard light used an average of 4hrs/day on Normal Rate electricity over 2 years:	-	Standard 100W Bulb (replaced 3 times at 25p) costs around £51 20W Low Energy Bulb (replaced once at £2.50) costs just under £13	£38.00
Standard light used an average of 8hrs/day on Normal Rate plus 2hrs/day on Cheap Rate electricity over 1 year:	-	Standard 40W Bulb (replaced 4 times at 25p) costs around £23 9W Low Energy Bulb (replaced once at £2) costs uner £8	£15.00
Standard light used an average of 2hrs/day on Normal Rate electricity over 1 year:	-	Standard 60W Bulb (replaced once at 25p) costs over £7 11W Low Energy Bulb (replaced once at £2) costs just over £4	£ 3.00
Halogen light used an average of 4 hrs/day on Normal rate electricity over 2 years.	-	Standard 35W Halogen Bulb (replaced once at £1.50) costs around £22 LED 2.8W Replacement Bulb (cost £9, not replaced) costs around £10.50	£11.50
Halogen light used an average of 4 hrs/day on Normal rate electricity over 3 years.	-	Standard 50W Halogen Bulb (replaced once at £1.50) costs around £46 LED 3.7W Replacement Bulb (cost £12, not replaced) costs around £15	£33.00

Note: The biggest costs associated with LED bulbs is the initial purchase cost which is still relatively high.

Lighting Control

Control		Costs	Saving
2 * 150W outside lights on for 0.5hrs/day on normal rate each controlled by PIR detectors with standby power of 7W each over 3 years	-	Powered continuously costs around £77 Powered via time switch (1W power - off for 12 hours a day) costing £8 costs around £56	£21.00

The figures for these examples were calculated using EnCalcE, an electrical saving calculator, which is free to download for personal use. Examples assume: Economy 7 Tariff - Standard rate electricity (18hrs/day) = 15.3825p/KW Hr, Cheap rate electricity (6hrs/day) = 7.2765p/KW Hr (the normal rate is the lower of the two standard rates, both figures include VAT at 5%). Inflation was assumed to be 5%/year which is probably an understatement

To check your electricity bill or predict how much electricity you are likely to use try using EnCalcEU, an electricity use, cost and prediction calculator.