Explanatory Note - Return on Assets ratios for electricity network - Updated September 2019

On 10 September 2018 we published Return on Assets ratios for the electricity network businesses we regulate. The publication of this information responds to calls from stakeholders for greater transparency around the actual returns achieved by the businesses.

Since publication of this initial information, we have begun to report Return on Assets ratios as part of our annual performance reporting. In some cases, the next round of reporting has updated the data and ratios previously reported. The most recent round of network Return on Assets ratios were published as part of the distribution network performance data 2006-2018 and the transmission network performance data 2006-2018.