These days we have all heard that switching your standard light bulbs to LED light bulbs save energy and saves money.

Most of the figures you see quoted are based on a series of assumptions and averages. This is all very well but we really want to know is; is it possible to to calculate how much you will really save by switching to LED lighting?


How LED light bulbs save you money

The technology of LED lighting provides cost savings due to two factors:

  1. LEDs need considerably less electricity to power than either traditional incandescent, halogen light bulbs, and even energy efficient light bulbs (CFLs). In fact typically, they require around 10% of the power required by other bulb types.
  2. LED bulbs last considerable longer than incandescent, halogen and CFL meaning you don't have to replace then nearly as often.

For example, a 6W LED light bulb is the equivalent of a 60W traditional halogen light bulb. That means the LED Bulb consumes 90% less electricity. That's not all, typically the lifetime of a LED bulb is over 15,000 hours, compare that to halogen bulbs that have an average lifespan of 1,500 hours. That means that LED light bulbs last 10 times longer!

How do the savings compare with CFL bulbs? Using a similar example, the equivalent of a 60W halogen bulb would be an 11W CFL bulb. The electricity saved by using an LED bulb compared with a CFL bulb is about 45%. That's still not the only saving, a good quality CFL bulbs' lifetime is around 8,000 hours, this is still less than half of the LED equivalent. So even if you're using CFL bulbs at the at the moment it still makes sense to switch them to LED.


Calculate the cost savings of LED light bulbs

You now have a better understanding of why LED light bulbs save on electricity bills. Let's look at how to calculate the savings you can expect to make by switching to LED lights.

To calculate the savings we need some information:

1. The total wattage of all your current light bulbs, spotlights & lamps. Just walk from room to room and note the wattage of each bulb. When you've been around every room, add them up to give you your total wattage.
2. The average time each light bulb is on during the day. Or if you prefer use an average of between 2.5 and 3 hours a day.
3. The current rate you pay for electricity per kilowatt hour (kWh, kW-h or kW h). You can find this on your electricity bill or by calling your energy supplier. The Energy Savings Trust calculates the UK national average price per kWh for electricity as 14.05p.
4. The cost of replacing each bulb with an LED equivalent bulb.


So here are the calculations for you

Current Cost per Month = (Current wattage / 1,000) x usage in hours p/day x cost p/kWh x 30 days
New Cost per Month = (New wattage / 1,000) x usage in hours p/day x cost p/kWh x 30 days
Monthly Saving = Current cost per month – new cost per month
Payback Period (Months) = Total cost of replacement bulbs / monthly saving
Total Savings = (120 - Payback Period) x Monthly Saving