To ask the Secretary of State for Energy and Climate Change what (a) mileage and (b) percentage of new power lines was laid (i) underground and (ii) overground in each of the last 30 years. (263057)

The Department is unable to provide historical data covering the last 30-year period. Ofgem the industry regulator has provided comprehensive data covering the periods 2005-06, 2006-07 and 2007-08 for both transmission and distribution networks across England, Wales and Scotland. These details are contained in the following table.

A large amount of new power lines are low voltage distribution lines in urbanised areas.