We're investing in robust networks

We're working hard to reduce the biggest single carbon impact of our distribution network: namely the electricity that is lost as it is transmitted across the network.

Our distribution business is split into two licensed networks, East and West. For 2007, losses in the East were estimated at 5.0% and losses in the West are estimated at 5.2% - both of which are among the lowest levels in the UK.

Estimated Electricity Distribution Losses (TWh)

2005	2006	2007
3.0	2.9	2.8

Prior year figures updated to ensure backward comparability

Estimated Network losses as % of electricity distributed

2005	2006	2007
5.2	5.2	5.1

2005 figure updated to include data previously unreported to ensure background comparability

Reducing losses further is no small challenge because we have to balance other requirements, such as network performance and investment efficiency. Any changes we plan to make must be balanced with other requirements, such as network performance and investment efficiency. So we're developing a careful approach to the future management of distribution losses. This is part of a long-term strategy and regulatory submission to the industry regulator Ofgem, for consideration in the next round of network investment.

Our continued investment in remote control technology, combined with an increased programme to prune or fell trees that could overhang our wires should bring significant improvements in network performance in future years. Year-on-year comparisons will also benefit from increased investment to upgrade our ageing network, with the subsequent outages this work will require.

High voltage test vans

Our electricity network is a significant asset and its cables and overhead lines could circle the world more than three times over. Consequently, any number of a variety of incidents can interrupt supplies to our customers. To enable us to restore these supplies more quickly, we invested substantially in two state-of-the-art, high voltage cable fault location vehicles. These vehicles have built in advanced diagnostic equipment. They enable our engineers to pinpoint quickly the location of an underground cable network fault, allowing them to carry out a more efficient repair and get our customers power restored more quickly.

Using our in-house expertise and by working with leading external researchers, we've developed a number of approaches, which include:

• Understanding specifically how and why power is lost on our network
• Looking at the costs, benefits and risks of altering the specification of network equipment like lower loss transformers and increased cable sizes
• Increasing the energy efficiency of our buildings to maintain a safe and suitable environment for our indoor equipment
• Creating a more efficient and robust network that will support our Changing Energy strategy by providing a better service for our customers.