Home Info and articles Energy ratings explained

Energy ratings explained

TL;DR Energy ratings for lighting are stated as a letter from A-F, with A being the most efficient. To make this confusing the ratings were updated in 2021. A product that was 'A' is now probably 'D' even though the product is the same.

Energy ratings are for easy comparisons

In the UK, lighting products and most other electrical appliances, (like fridges and washing machines etc) have had an energy rating applied to them for many years. This has always been A-E and is supposed to be an easy way to tell which product is the most efficient. ‘A’ rating is the most efficient.

The most efficient products use less energy to get the same job done. For lighting, this means producing the most light for the smallest amount of electricity.

Energy ratings over time & bringing it up to date

As fluorescent and then LED lights developed and became more popular, the ratings became less and less useful as almost all new products qualified for an A rating. The solution was to add new ratings for A+, then A++, then A+++. Obviously, this wasn’t a long-term solution.

Towards the end of 2021, new rules came into effect, nattily named ‘The Ecodesign for Energy-Related Products and Energy Information (Lighting Products) Regulations 2021’. You can read all the exciting details on the UK government’s website.

These regulations contain a lot of words, but the thing that we are talking about is the energy rating. The old A+++ to E scheme has been replaced with a completely new and utterly different A-G scheme.

There are new labels too, that you will see on product packaging. As you can see below, the new-style labels are completely different to the old ones so there’s almost zero chance of confusion:

Example energy rating labels

Old-style energy rating label
Old-style energy rating label
New-style energy rating label
New-style energy rating label

As before, the label and the energy rating are designed to make an easy comparison of efficiency between similar products. The new labels also have more information including manufacturer information and a QR code to link to product information.

The biggest difference under the new rules is that it’s much more difficult for a product to qualify for an ‘A’ rating. At the time of writing, getting an A rating would require technology that doesn’t currently exist. This leaves some scope for further product development.

What’s the problem with the new energy ratings?

From a consumer’s point of view, the important thing to remember is that existing products have been re-rated. A light previously rated at A++ is now probably rated ‘E’, or ‘D’. That doesn’t make it any less efficient - it hasn’t physically changed. Power consumption and light output are the same. It’s just the label on the box that’s been updated.

As new products filter through to customers with the new labelling on them, it would be very easy to compare the box for a new product to the box for an old one, then reach the incorrect conclusion that the new one is worse than the old one.

Working it out for yourself

With lighting, to make a sensible comparison between something you just bought and something that’s been in the back of your cupboard for a few years, you should compare the amount of energy used (in watts or ‘w’) and the amount of light produced (in lumen, or ‘lm’). Higher lumen & lower watts = more efficient.

You might even want to do some basic mathematics and calculate a figure for ‘lumen per watt’ by dividing lumens by watts. Higher lumens-per-watt is more efficient.


Light bulb A: Uses 4 watts of power to make 360 lumen = 90 lumen per watt

Light bulb B: Uses 10 watts of power to make 1200 lumen = 120 lumen per watt

120 is more than 90, so Light bulb B is more efficient.

(Although it does use more than double the amount of electricity than light bulb A while making more than three times the amount of light.)

The energy labels and their new A-G ratings are supposed to remove the need for doing any sums, but in the real world, sometimes you just need to understand the underlying data.