# Energy Efficiency Ratings Explained

> The energy efficiency rating system was invented in 2012 While it was quite useful for consumers to quickly compare the energy efficiency rating of a similar p

Source: https://help.downlightsdirect.co.uk/en_gb/energy-efficiency-ratings-explained-BJcIV9TVA

Last updated: 2024-12-31T10:53:02.001Z

The energy efficiency rating system was invented in 2012. While it was quite useful for consumers to quickly compare the energy efficiency rating of a similar product, it had no room to scale and didn't account for future technological advances. Leaving you with a system that would have mainly been A++ and higher. Why didn't they start off in the middle of the alphabet? 

In 2021 the system got changed but rather than use a new system with new letters or numbers they just adapted the same broken system to make it more confusing.

The tables below show what each label represents:

![](https://cdn.prod2.kustomerhostedcontent.com/media/66200fa32247364c5f09ab92/fbd1976f8842cac195f4e06ce983757b.jpg)

An LED light bulb from the original 2012 system with an impressive 120 lumens per watt would have had an A++ rating, the new 2021 system downgrades the same product to an E rating.

You're still getting exactly the same specifications, the brightness (measured in lumens) and energy consumption (measured in watts) is the same, but the energy rating has changes.

Having the same lumens and wattage means that the lumens per watts is still the same. Often shown as lm/W, this is the common variable between light production and energy consumption.

## Efficacy

The word efficacy is used to describe energy efficient with lighting as there are other variables to consider with them. Such as the total wattage, which might include an LED driver, the light output ratio, which tells you if you lose any light within the fitting, for example a 50W halogen used to lose 10% of its light in its reflector.

The way energy ratings are calculated for any lighting product is to determine the efficacy. To do this you divide the lumens by the wattage. This gives you the lumens per watt, it tells you how many lumens you get for 1 watt of energy consumption.

## Example

For example a [5W LED GU10](https://www.downlightsdirect.co.uk/aurora-enlite-5w-gu10-led.html) with a 520 lumen output has an efficacy of 104 lumens per watt. This would put it in the F rating bracket, when it used to A+ rated.

![](https://cdn.prod2.kustomerhostedcontent.com/media/66200fa32247364c5f09ab92/338acf77b8abe291f651caa02eb9411e.jpeg)

## The Most Efficacious Lights

This new system has come very early for GU10 LEDs and integrated LED downlights. The most energy efficient GU10 LED is only is the [Philips 2.1W GU10](https://www.downlightsdirect.co.uk/philips-masterled-b-rated-gu10-led-lamp-2-4w.html). With a light output of 375 lumens, it appears to have an efficacy of 178 lumens per watt, on paper it looks like it should be classed as C rated but Philips have explained that GU10 lamps and other directional lamps are calculated differently to other light bulbs...

The way EEL(Energy Efficiency Label) is calculated for directional light is different than that of a bulb.

Taking the index of 1.176, you will get a Class A grade, it is the same case for future A class GU10, and also the same for competitors.

The calculation is: 1.176 X 178 = 209lm/W

![](https://cdn.prod2.kustomerhostedcontent.com/media/66200fa32247364c5f09ab92/34863c526e0a04236503788f6558c956.png)

![](https://cdn.prod2.kustomerhostedcontent.com/media/66200fa32247364c5f09ab92/a58579f01e888f0572f71a5a0fac6a08.jpg)

We anticipate a new generation of integrated LED downlights to surpass these in 2025 as this is the only next logical step for LED lighting technology, especially in a more energy conscientious age.

## Summary

Don't spend too much time looking for LEDs with a certain energy rating as the system still needs some work. Just calculate the lumens per watt and you'll be able to compare it to another lighting product.

## More Information

1.  [Integral LED Label News Article](https://integral-led.com/en/content/new-lighting-regulations-2021) - Very informative
2.  [Energy Label Website](https://energylabel.org.uk/the-new-label/products-affected/light-sources/) - Very vague about lighting
3.  [Energy Saving Trust](https://energysavingtrust.org.uk/energy-labels-are-changing-heres-what-you-need-to-know/) - Very little information about lighting
4.  [Philips Website](https://www.lighting.philips.co.uk/prof/led-lamps-and-tubes/led-spots/master-ledspot-gu10-ultraefficient/929003610102_EU/product) - Shows the 2.1W A Rated LED