Should I change to LED bulbs?
Is it worthwhile changing to LED lighting? This is the question we are most commonly asked as electricians. As you might expect the answer starts it depends.
For the moment let’s assume you are asking the question because you want to reduce your electricity bill. If this is the case the most important thing that the answer depends on is what type of light bulb are you thinking of changing. Below I have considered the potential savings when changing an incandescent (filament) bulb for an LED and when changing a compact fluorescent bulb for an LED.
For both cases I have made the following assumptions: the cost of a good quality 7 watt LED bulb is about £7.00; the light is on for 5 hours a day; and electricity costs 14p per unit.
Let’s first look at changing a 60 watt incandescent bulb for a 7 watt LED which are roughly equivalent in terms of light output. In this case you will save approximately 3.7p per bulb per day. At this rate it will take about 200 days to pay for the new LED bulb and you will save about £3.30 per bulb on your quarterly electric bill. It therefore seems clear that there is a good financial case to change incandescent bulbs for LED ones.
However if saving money is what has brought you to this blog then it is worth remembering that in most cases lighting makes up quite a small proportion of your energy bill and there may be better ways to save money. For instance if you have not insulated your loft doing so will almost certainly give you a better return on your investment than changing your bulbs. If you have everything else covered then it is also worth remembering that turning off lights and other electrical items that are not being used is always going to be the easiest way to reduce your electricity bill.
Let’s now look at the case for changing a 10 watt compact fluorescent bulb for a 7 watt LED which are roughly equivalent in terms of light output. In this case you will save approximately 0.2p per bulb per day. At this rate it will take about 3750 days (more than ten years) to pay for the new LED bulb. 3750 days is approximately 19000 hours which is only slightly less than the 20000 hours which is often claimed as the life expectancy of a LED bulb. This means that you would expect to have to renew the LED bulb soon after it has paid for itself leaving very little opportunity to save any money. In conclusion there does not seem to be a financial case for changing compact fluorescent bulbs for LED bulbs.
Aside from saving money it is worth noting that LEDs switch on at full brightness straight away unlike compact fluorescent bulbs which can take several minutes to warm up. If this warm up period is a problem for you then LEDs could be a good solution.
The main other point to consider is that LEDs often do not play nicely with many dimmer switches. Incompatible dimmer switches can cause LEDs to buzz flicker interfere with radios and switch on unreliably. If you are updating a light operated from a dimmer switch you will have to get a dimmable LED which will be more expensive and you may well have to change the dimmer switch which could cost approximately £15.
As mentioned above a life expectancy of 20000 hours is often claimed for LED bulbs. However I have heard of cases of cheaper LED bulbs only lasting a matter of weeks. If you have decided to make the change I recommend that you stick to products from reputable manufactures. As always if a bargain seems too good to be true then that is probably the case.
The One last point to consider is the colour of the light given off by a LED. Typically manufactures sell bulbs producing a warm white light, This should be similar to the light given off by an incandescent bulb and cool white which is harsher. Manufactures and retailers may also refer to colour temperature which may seem a little confusing in that the lower the temperature the warmer the light. For instance temperatures of approximately 2400 K and 3500 K are respectively roughly equivalent to the warm white and cool white referred to above. If you are confused take a look on the packaging which often displays a colour chart to help clarify this.