Undergrounding of overhead lines: Electricity distribution (RIIO-ED1)


Source: RIIO Electricity Distribution annual report 2017-18.

Information correct as of: March 2019

This chart is an indicator of environmental impact. It shows the length of overhead lines removed in National Parks, Areas of Outstanding Natural Beauty and National Scenic Areas. In RIIO-ED1, each distribution network operator is able to recover a defined amount of funding to pay for undergrounding of network cables in these designated areas.

We update this chart on an annual basis. Click the ‘more information’ tab above for a summary of the latest trends, details of how to interpret the figures and for information on methodology.

Policy Areas:

  • Electricity - distribution

Data Table

Undergrounding of overhead lines: Electricity distribution (RIIO-ED1)
Distribution network operatorsLength of installations (km)Total expenditure (GBP £ million)
Electricity North West4.461.08
Northern Powergrid15.622.41
Western Power Distribution9.451.27
UK Power Networks3.450.23
SP Energy Networks5.460.49
Scottish & Southern Electricity Networks2.511.02

More information

Undergrounding of overhead lines: At-a-glance summary

In 2017-18 approximately 34km of overhead lines were removed and approximately 41km of underground lines installed by the distribution network operators at a cost of £6.5 million.

Relevance and further information

Undergrounding reduces the visual impact of overhead lines on the environment. This contributes towards the environment output the distribution network operators must deliver for customers.  


Allowances are calculated to reflect stakeholder interest in visual amenity and each network operator’s funding is based on the amount of its network in Areas of Outstanding Natural Beauty and National Parks.

Each year, distribution network operators must report on expenditure and activity related to undergrounding. This allows us to determine if they are meeting stakeholder requirements.

Date correct
March 2019
Policy area