Our friend and LED light enthusiast Simon Brammer, from Ashden, on the intricacies of LED lighting…

The humble light bulb hasn’t really changed much since its invention by Thomas Edison in the 1880s – until recently, that is. You may not have noticed yet, but lighting is undergoing a revolution. The good news is, you can join it, saving yourself a small fortune in the process.

Why do ‘old-style’ bulbs waste so much energy? Well, just think about when one of them blows – and they do a lot – you can tell how inefficient it is because you have to wait for it to cool down before you can change it, or you’ll undoubtedly burn your fingers.  This is why they are so wasteful: they produce huge amounts of unnecessary heat as well as light.

But things have moved on in recent years. First there was the compact florescent bulb and then there was the LED. LED lights use a fraction of the energy of a traditional bulb, and considerably less than fluorescents too. Early LED lights, a bit like a bad first date, left a less than attractive initial impression. They emitted a poor, white, can-hardly-see-where-I’m-going light. Unfortunately this is how many people still remember them.

But that was then and this is now.  Now, you can get LED lights in any colour, brightness or warmth you like.  What’s more, with costs having fallen massively, they have an average payback period of less than six months, and are a really easy way of reducing your energy bills.

I’ve helped hundreds of people to switch their lighting to LED.  Take my friend John.  We replaced 20 ceiling spotlight bulbs in his sitting room, hallway and kitchen at a cost of just over £100.  The cost of running those lights has now dropped from £432 per year to £34.  You can do the maths for yourself but suffice to say, John and his wife are now spending the money they’ve saved on more important things in life, like their recently born son.

The trouble is, if you’re not an LED fanatic like me, knowing which bulbs to buy is often pretty confusing. So to help you join the LED light bulb revolution, here are a few questions to help ensure you get the bulbs you need:

What’s on? It sounds obvious, but the best place to start is to work out which lights are on the most, and replace them first. In this way, you will maximise your saving.

How much light?  Light is measured in lumens, but this is too complicated to work out every time you buy a bulb. So as rough guide, if you want the equivalent of an ‘old school’100 watt light bulb, go for 10 watts, 60 watts – 6 watts, 40 watts – 4 watts. The mathematicians among you will spot a rough 10% rule.  For spotlights, replace a 50 watt GU 10 with a 4 watt LED bulb.

Which colour?  Light temperature (colour) is measured in Kelvin (K).  The lower the number, the warmer the light.  Because I like a warm light, 2700K is my preference – it’s like the light from an old-fashioned bulb (see pictures). 3000K is less warm, and then as you go up the light becomes cooler and whiter – anything approaching 5000k will be nearly blue.  Sometimes these are called ‘warm white’ or ‘cool white’.  So, depending on your preference, check the packet to make sure have the right colour for you.

Do you want to dim your lights?  You will have to pay a little more for dimmable bulbs. but they are available across the range.  Look for the ‘dimmable’ symbol on the packet.  Just a word of warning – occasionally, because LED lights use so little energy, you may need to change your dimmer switches too (ask a qualified electrician to do this for you).

Got the right fitting?  You will have a range of light bulbs in your home with different fittings – just make sure you match the fitting to the one you are buying.  The best way to do this is to take the old bulb along with you. If you are replacing down-lights or spotlights, take one out (when it is cold and switched off) and see if it has ‘pegs’ or ‘pins’. If it has pegs, this is mains voltage (a GU10 fitting) and is no problem to change.  If it has pins, this is low voltage lighting and is a little more complicated.  You may need some advice from a professional as to which bulbs will work in your home.

Finally, when you are changing your lighting, think of it like re-decorating a room, where you would buy a ‘paint tester pot’ to see if you like the colour first before you paint the whole room.  When you are investing in new bulbs, buy one first to see if you like it before you replace the rest.  And remember, most places will exchange the bulb if it is the wrong one for you.

Once you have changed your bulbs, you can sit back (you won’t need to get up to change them for an average of 15 years) and bask in their glow – and be smug in the knowledge you’re quids in.

Simon Brammer works for sustainable energy charity Ashden.  He provides ‘bulb advice’ to family and friends in his own time. To find our how much LEDs could save in your home, book a Home Energy Masterplan.