Investing in secure and reliable delivery networks

We're investing heavily to upgrade our distribution network, which will provide our customers with a secure and reliable delivery service.

Keeping the lights on - our key priority

Our electricity network is vast; its cables and overhead lines alone could circle the globe over three times, so it's no surprise that occasionally incidents interrupt supplies to some customers. Our priority is always to restore supplies as quickly as possible.

The standard industry way of measuring performance is to count the number and length of interruptions to supply. These are defined as the number of supply interruptions (power cuts) per 100 customers per year, and the average number of minutes without power per customer per year. Short interruptions that last less than three minutes are not included as these generally relate to automatic operation of the network.

Our performance compared with target was slightly disappointing for both customer interruptions (CIs) and customer minutes lost (CMLs). This was mainly due to the strong winds in spring and a very wet summer. However, performance in 2007 did show an improvement over the previous year.

East region

East Region	2007 Actual	2007 Target	2006 Actual
CML	74.3	68.8	76.1
CI	78.9	78.5	83.9

West region

West Region	2007 Actual	2007 Target	2006 Actual
CML	101.7	85.3	106.4
CI	110.7	109.2	125.8

We experienced significant disruption to our networks over five days in January 2007 when wind speeds reached 70mph - the strongest gales in over five years. Unfortunately, over 315,000 customers had their supplies affected. In addition to the yearly customer minutes lost and customer interruptions figures above, the East region experienced an extra 5.14 CIs and 14.47 CMLs and the West region an extra 7.64 customer interruptions and 29.95 CMLs.

We've also invested in two advanced technology high voltage cable fault location vehicles. These self-contained vehicles have sophisticated diagnostic equipment to help our engineers quickly pinpoint the location of an underground cable network fault. This allows a more efficient repair and restoration of customer supplies. Customers are now also able to see web-based real-time updates on the faults interrupting their local power supply.

We have in place long-term plans to maintain our assets and invest in them when needed. It's important to plan decades ahead to ensure that the future needs of our customers will be met. We develop proposals on a rolling basis to address the risks we might face and the potential for long-term improvements and upgrades. These are reviewed against current performance levels.

Our medium-term investment in the network is funded in separate five-year 'price control review periods' which are agreed with Ofgem. The current five-year period began in April 2005, and includes a substantial increase in investment to ensure we can maintain the integrity of our network. Our investment of £1.2 billion will help us maintain and improve the service we provide our customers and is an increase of some 55% over the previous five years.

We connect renewable and other forms of distributed generation to our network, working with developers to find the most technically and economically viable solution.

Distributed generation allows us to adopt more innovative approaches to network issues. If emerging technologies such as micro-combined heat and power (mCHP) and other low-carbon forms of generation are to flourish, there will need to be substantial new investment to give our network the increased flexibility it will need. In April 2005, Ofgem introduced the Registered Power Zone (RPZ). This initiative provides a financial incentive to distribution companies that develop and implement innovative projects with intention to enable distributed generation to be added to networks where this may not have otherwise been economically feasible. We have the UK's first RPZ on the east coast of England. It uses an automated control system capable of analysing the network in real time sending signals to the distributed generators connected to it.

Throughout 2007, we suffered a sharp increase in thefts and vandalism at our electrical substations. Thefts of copper earthing tape and other vital equipment have led to more than 50,000 customers losing their electricity supply. In an attempt to minimise this inconvenience, we've been working with Crimestoppers - offering a reward of up to £1,000 for information leading to the successful prosecution and conviction of those responsible. We've worked with the police to implement a number of security measures, including CCTV, at our 97,000 substations where appropriate.

We also launched a media campaign in June focusing on the areas with the highest number of incidents - Shropshire, Staffordshire, Derbyshire, West Midlands, Nottinghamshire and Northamptonshire. High-profile media coverage helped to highlight the physical dangers of breaking into substations and has led to two pending prosecutions.

We are eager to support research carried out at some of the UK's leading academic institutions, so we have a new initiative that will sponsor a range of distribution-related projects at a number of leading universities. A detailed study into the effects that changes to the climate will have on the electricity network is being undertaken. This is looking at the effects that changes to temperature and rainfall can have on the network and how it might affect our customers' demand patterns.

The electrical losses inherent in any electricity system are of particular importance, so we're undertaking a detailed research project to help us design future networks that will lose minimal amounts of power.

In designated 'Areas of Outstanding Natural Beauty' and National Parks, we're working with local environment groups to place some of our overhead lines underground. Whilst the scale of the project is inevitably limited, we're doing as much as we can.

Recent floods across the UK have underlined the need to start building greater resilience into the network so that supply interruption through flood damage is reduced. Using information from the Environment Agency, we are undertaking a detailed risk assessment of our assets. The investment required will continue into the next review period, until 2015.