New consumer research by JD Power has revealed that residential energy prices have increased dramatically, while customer satisfaction has dipped, during the past 12 months, the BBC reports.

While electricity prices have increased by a significant 13.7% since autumn 2005, the most dramatic change has occurred in the wake of a volatile and often delinquent recent wholesale gas market. In fact, alarmingly, according to the JD Power survey end user gas prices have risen by 33% over the course of the last year.

The BBC reports that JD Power found that the average gas bill rose to GBP510.60, while electricity bills climbed to GBP453.24.

Meanwhile, findings on customer satisfaction echo last month’s announcement from the energy watchdog Energywatch. JD Power’s research revealed that general customer satisfaction towards their energy suppliers has decreased in the last year. However, while Energywatch’s research indicated that British Gas was the least satisfying, JD Power’s study points the figure at French owned EDF Energy.