Selection criteria

How are the Topten lists compiled?

Topten aims to showcase the most energy-efficient products currently on sale in the UK. Based on an overview of available models in a given product category, we apply a set of stringent selection criteria and calculate the each model’s Energy Efficiency Index (EEI) to identify the top ten most efficient models. 

What is the Energy Efficiency Index (EEI)?

The EEI is the rate of energy consumption based on a variety of aspects impacting on the energy efficiency of an appliance, including typical usage patterns, the size of the appliance, product-specific technologies used and functional features (such as frost free for fridges). The lower the EEI, the more efficient is the product. 

Why are there fewer/more than 10 products in each list?

When new energy-saving technologies become available, there is frequently a time lag in these becoming dispersed across the entire market and for a while only a small number of models will feature this ‘best available technology’ before it eventually becomes the mainstream. 

Our selection criteria for each product group are designed to showcase the models that benefit from this market-leading technology. As a result, sometimes there may be fewer than ten models that meet the requirements of our selection criteria. 

By providing advice to consumers on which the most energy efficient products are and encouraging greater uptake of these products, Topten aims to accelerate dissemination of best available technology across the range of models put on the market by manufacturers.    

Where does the information come from?

Topten uses information from a number of sources including: 

  • Manufacturers’ declarations (according to the standards of the EU Energy Labels)
  • An independent market database
  • Topten Best of Europe (

Topten verifies all calculations related to energy label declarations with each manufacturer prior to inclusion on the site. Where manufacturers have not provided the required information to Topten, the models concerned will not be featured in our listings.

What is the ‘inefficient model’?

Topten lists contain an anonymised ‘inefficient model’ which represents an anonymised product from a lower energy class of a similar type to those featured in the Topten list.

The purpose of displaying this model is to allow comparison and to highlight the difference both in terms of purchase price and energy consumption.