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Getting the best out of LEDs – what you need to know

Hanging lamps

When home furnishing giant IKEA shifts its entire lighting range to LED, you know that LEDs are not the lighting of the future any more, or just a nice decoration for Christmas trees, but the practical lighting choice of right now.

With the help of our technology experts, we've put together 10 key points you should have in mind when looking to invest in these high-efficiency lights.


How efficient are they?

There has been considerable progression in recent years in the efficiency of LEDs bulbs.  This can be measured in the amount of lumens per Watt  – how much light you get for each watt of electricity consumed. The technology has made big improvements in the last few years, outpacing efficiency and cost projections and strongly establishing LED products in the lighting market.   They are now the stand-out mainstream performer if you're looking to cut costs and shift to greener options in lighting your home.

Hanging LED lights


Getting the light right

Colour temperature is measured in kelvin (K). The higher the kelvin you go, the 'bluer' the tone will be. This is closer to natural light, and is a more common choice in homes in other parts of Europe such as Scandinavia and Italy. 2800K is warm white, which tends to be more the colour temperature preferred in UK homes, and it's what you'll need when replacing halogens. Getting what's right for you is all about personal taste, and the ambience you want to create in different parts of your home.


Each room is different

Lighting is an individual thing, but there are some commonalities for rooms around the home. Kitchens tend to need areas of concentrated light for intricate tasks. Here, it’s important to note the luminous intensity of LEDs for spotlighting, which is measured in candela. A more yellow tone of light is generally preferred in sleeping areas. A higher kelvin, with cooler light, might be desired in bathrooms or where a more natural light is desired.


Woman reading on couch in living room


True colours

While knowing your lumens is important when it comes to LED performance, colour rendering – how vivid colours look on objects when the light hits them—is also important. The higher the rating, the more vivid colours will look, and LEDs have been catching up with halogens in this respect. The colour rendering scale goes from 0-100, and some LEDs are now getting into the mid-90s. 


Check the packaging

The best place to start in making the right choices for your home's needs is to decide what you are looking to achieve in each room, and then take a look at the packaging of LED bulbs. It includes all the information about the light output, and if you still prefer to think in Watts, it will include a comparison to an incandescent bulb of the same brightness.  The packaging will also include the colour temperature and important aspects such as dimmer compatibility. For spot lighting, the spread of light is denoted by the beam angle, another consideration to ensure you have the coverage you want.


Shape and style

These days there are few limits to where you can use LEDs to replace halogens, CFLs and incandescent bulbs. You can get LEDs for all types of spotlights, lamps and integrated light fittings – including some more niche shapes such as thin, linear lighting.

Assorted LED bulbs

Fitting up

There are a range of fittings to suit your home's needs. Replacements for traditional bayonet bulbs are still widely available from most manufacturers, although the Edison screw fitting is becoming more common. This exists in both large and small screw types. Fittings with two pins (GU10 and GU5.3) are very common, particularly for spotlights – and these come in larger and smaller sizes, with the pins different distances apart.


Dim and dimmer

It is possible to dim a far bigger range of LED lighting than just a few years ago, with much greater compatibility with dimmers across product ranges. Again, you can find out whether the product is dimmable or not on the packaging; but it's also worth checking compatibility with the kind of dimmer you've got. Most staff in retailers where LEDs are available should be able to advise you on this.


Bunched up twine leading to lightbulb


Best in class?

A couple of years ago, Energy Saving Trust was involved in a Europe-wide project called PremiumLight, which did some spot-testing of LEDs and other energy efficient lighting. Although LED products are improving rapidly, so there's been some change since then, the results are a useful indicator of the brands that tend to perform well.

There are some good smaller entrants to market recently, making discerning choices on what to import, so it's worth asking for advice in-store when you're making a purchase, or looking at online reviews before you buy.


It pays to go LED

As an investment, LED advantages certainly outweigh costs. When comparing lighting with similar outputs, a 17W LED light will cost you around £1.85 a year compared with £5.55 for a 50W halogen.  LEDs also last for 20-25 years – over the lifetime of a bulb you could save £80 in running costs by switching.  Of course to realise these savings and life times, it's important to buy good quality brands and products.

LEDs are still more expensive than halogens, but you can now get good-quality bulbs for under ten pounds that will pay for themselves within 2 years. Given the amount of light you'll get out of them over the years, sometimes it can be worth even spending a bit more than that for the right bulb. 

Gary Hartley's picture
Gary Hartley is Energy Saving Trust's expert blogger. He has extensive experience researching and writing on a number of topics, with particular expertise in sustainable energy, policy, literature and sport. As well as providing regular blog content, Gary has also been published in numerous magazines and journals.

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I would appreciated if you could provide a more details of your estimation as I'm not sure if I understand correctly your assumption of savings ? so the cost of the LED light a year is £1.85 ? what is this cost based on ?
What is the cost of the LED light ?
How many hrs during the year this light will be used ?
is this estimation based on an average house-hold ?
what is the lifetime of one LED light ?

Im asking all those questions because i found an information on the Energy ST website that the average lifetime of the LED light is 25000 hrs. This accounts for 2.8 of the year. Basing on your annual assumption of cost, one LED light would cost £5.27 per year and would last 2 and just over 9 months . This cost of a unit is lower than your further assumptions, as you stated that i can get a good LED light for just under a ten pounds !

I also dont understand why you are stating that the lifetime of LEDs is 20 to 25 years , what that actually means ?
I would appreciate if you could provide a further explanation on the above and tell me what is the approximate cost of installation LED in an average house hold ? what is the lifetime of the light in hrs and potential savings in the energy usage which are expected average house hold ?
I know it is a lot of questions but i try to understand what are the real benefits of installations of energy saving lights

Many thanks


Hi there Hona,

Thanks for getting in touch. We have spoken with our Project Manager and lighting expert to help answer your query:

"The lightbulb’s quoted lifetime is based on it being in use for 790 hours per year (around 2 hours use per day). This is based on research into the typical times that light bulbs are used in households; some householders may have the lights on for more or less hours though. So, based on a typical electricity price of 14 pence per kWh, a 17W bulb that’s on for 1000 hours will cost around £1.85 (17W for 1000h = 17kWh).

The estimation is based on average households. Some LED bulbs claim a lifetime of 25,000h, so this equates to 25 years but it's hard to definitively back that claim up (‘accelerated’ testing is generally carried out with some extrapolation). Many manufacturers now claim 15,000h (such as Philips, Integral), even though it’s expected the bulb will last longer than this.  

Savings are compared to halogen or incandescent bulbs; you can find out more from our Energy efficient lighting content. In addition, you can find some estimated comparisons on the Topten website, too.

100W incandescent replacement bulb

Purchase cost

Annual running cost

77W Halogen






A D-rated, 100W replacement halogen would typically use about 75-77W and would only cost £2-3 to buy, but it  would cost about £11 a year to  run. A good 100W replacement LED bulb from a reputable manufacturer will typically use 13-14W and now many cost under £10, and so it can pay for itself in around a year.”

We hope this is helpful.

Can you please clarify if it advisable and therefore safe to us LED's in bathrooms?

Hi Derrick,

The answer is yes; LEDs are safe to use in bathrooms.

You may wish to learn more about the Ingress Protection rating that a bathroom LED luminaire should have.

IP ratings are often specified on streetlights to ensure they don’t break by allowing water or dust to get in, but also on relevant indoor lighting products. Here’s a helpful diagram showing bathroom ‘zones’.

The luminaire must have an appropriate IP rating to be used in a bathroom – this would be the installer’s responsibility.  According the highly reputable IET, anything in a potentially dangerous place should have at least an IPX4 rating.

We hope this is helpful.