UCL Psychology and Language Sciences


Watt are you waiting for? Make the switch to LED bulbs!

Members of the PALS Green Impact Team have made lifestyle changes to help the planet. We spoke to Dave Hetherington (PALS IT Manager) who switched from incandescent bulbs to LED bulbs.

LED bulbs

In 2014 I was lucky enough to get onto the property ladder, the downside to that was you suddenly become very aware of how much everything costs, in the first couple of months our energy bills were really high, so I set about reducing this.

Despite our house being of average size, the previous occupants must have been training to be electricians, there was an inordinate number of light fittings, a prime example of this was the 9 x 60W bulbs in the kitchen that would normally have had 2 or 3 at the most, that seemed a good place to start, so I did the math, guesstimated they were on for 4 hours per day (more in winter/less in summer, it seemed a good approximation), I used the following to determine the cost per year:

  • 9 Bulbs x 60W = 540W or 0.54kW
  • 4 hours per day x 365 days = 1,460 hours usage per year
  • 0.54kW x 1,460 hours = 788.4kWh of electricity used per year
  • 788.4kWh x 15p per kWh = £118.26 per year, just to illuminate our kitchen

By contrast, an LED bulb of equivalent brightness would only use 7W, so using the same method:

  • 9 Bulbs x 7W = 63W or 0.063kW
  • 4 hours per day x 365 days = 1,460 hours usage per year
  • 0.063kW x 1,460 hours = 91.98kWh of electricity used per year
  • 91.98kWh x 15p per kWh = £13.80 per year, much more affordable.

The cost saving seems obvious, £118.26 vs £13.80 per year, it’s a no brainer, however, the LED bulbs are more expensive, or are they?

The bulbs we needed had an approximate life of 25,000 hours, based on our usage of 1,460 hours per year we should expect over 17 years of life from this bulb, even if they only lasted half of that estimate we’d still have saved over £100 per year in energy bills.

You can currently get a 4 pack of these particular bulbs for £22, so to replace all 9 would cost £49.50 and we’d be saving money as well as energy 6 months after purchase/installation.

Now some of you may be skeptical, yeah, ok, I could save that money if the bulbs last that long, well we made the switch 7 years ago and we haven’t had to replace one of these bulbs yet. So, our experience is that this is worth the effort, it’s a win win situation, you save money, you use less energy.

In my example, we went from using 788.4kWh down to 91.98kWh, a reduction of over 88% and 696.42kWh over the year.

So watt are you waiting for? Make the switch!