The company’s 2014 B2B Energy Buyer Customer Satisfaction research shows that Smartest Energy is the highest rated provider for MEU; Opus Energy is the highest-rated provider for SME users; and Haven Power is runner-up in both markets.
Opus Energy recorded a rise of 0.34 from 2013 to rank first, while Haven Power moved up from third place to second, improving its score from 7.18 to 7.55 in the SME league table.
The overall market average however, declined from 7.03 in 2013 to 6.86 in the first half of this year.
Haven Power, which is the retail arm of generator Drax, also increased its score in the MEU Power League to 7.49 in 2014, up from 7.39 last year.
The overall market scores dropped again, from 7.41 in the previous survey to 7.14 in the first half of 2014.
Large supplier SSE dropped its score from 7.18 in 2013 to 6.70 this year to rank at number eight on the MEU league table, the same as last year.
Npower improved on its 2013 score of 5.70 to 6.33 in 2014 but still ranked bottom of the SME league table.