EDF Energy

Supplier Ratings Explained

In order to ensure that the information that we provide to consumers is impartial, we use external data for supplier service ratings.

We work with J.D. Power and Associates to provide this information which is generated as a result of customer surveys.

About J.D. Power

J.D. Power and Associates is a leading international marketing information firm, specialising in understanding customer satisfaction dynamics and helping clients improve their satisfaction performance. The company was established in 1968 and, with offices in North America, Europe and Asia, now has over 800 employees worldwide. In 2005, the company became part of the McGraw-Hill group.

J.D. Power and Associates’ experience spans many industries including Telecommunications, Energy, Hotels, Financial Services, Healthcare, Travel and Automotive.

The company is recognised as an international authority on customer satisfaction measurement and evaluation and is able to provide clients with global/pan-European comparisons in selected industries.

J.D. Power and Associates’ syndicated studies are designed and funded by J.D. Power and Associates, providing an independent evaluation of the performance of the leading companies in the market.

Customer satisfaction data used on this website are a result of findings and conclusions from the eighth annual UK Syndicated Gas and Electricity Customer Satisfaction Studies.

Key Drivers of Customer Satisfaction

The factor structure for the 2008 UK Gas and Electricity studies remains the same as that used in the previous year following a change of methodology in 2007 from telephone interviewing to online self-completion. The Index measures customer satisfaction with the energy supplier and provides an overall understanding of the drivers of customer satisfaction in the UK energy supplier market.

The Index is calculated from 51 individual questions in which respondents evaluate their experiences. Factor analysis groups these questions into six “factors”, each of which contains closely correlated questions. Regression analysis then calculates weights for each factor based on the relationship between the factors and the overall level of customer satisfaction with the energy supplier.

The Rating Scale

In the Gas and Electricity Supplier surveys, consumers are asked to express their level of satisfaction with their energy supplier by rating its performance on a number of attributes using a 10-point numerical scale.

Our methodology uses the “maximum 1,000” Index, in which all ratings for a particular attribute are averaged and the mean score for that attribute multiplied by the question weight, then by the factor weight. The resultant number is then multiplied by 100. All attributes are treated in this manner, and then added together to arrive at the final Index score. The maximum possible Index score is 1000.