Part 1
The Electricity Industry
2
Electricity Industry Structure
2.1 Outline of chapter
This chapter describes how the electricity industry developed so that we can more easily understand the differences between the old nationalised industry and the current privatised one; and, explaining why we must from now on talk about “licence-holders” and not “electricity companies”. This chapter also illustrates who owns and runs what and in respect of which region.
2.2 From original legislation to nationalisation
The aim of the original legislation, the Electric Lighting Act 1882, was to “facilitate and regulate the supply of electricity for lighting and other purposes in Great Britain and Ireland”. While this was primarily related to lighting this also provided the first definition of “electric line”. Local distribution networks were established by private companies who also generated electricity and provided supplies to individual customers. In urban areas local authorities established electricity departments to carry out similar functions. A third category of joint electricity authorities completed the suite of authorised electricity undertakers. The rights obtained from owners and occupiers to run electric lines at voltages as high as 132,000 volts were the same as those that applied to local supply lines, then at 240 volts.
Change followed at a rapid pace in the early part of the 20th century. To meet the increasing demands for continuity of electricity supply the Central Electricity Board connected the regional networks of 132,000 volt overhead lines into a national gridiron. This was completed in 1933. This was not originally intended to be a national grid but a series of regional grids supplying local demand; they were however interlinked so that regions could help each other in supply emergencies. In 1938 they began operating as a national system.
The industry was nationalised in 1947 by the Electricity Act 1947. Under this Act the assets of the Central Electricity Board and the other authorised undertakers became vested in new statutory corporations. The 1947 Act also created the British Electricity Authority, renamed in 1954 as the Central Electricity Authority1 which in 1957 became the Central Electricity Generating Board2 (CEGB). The 1947 Act also created the 12 Area Electricity Boards of England and Wales.
So far as the general public was concerned the face of the electricity industry in the era of nationalisation would have been the Area Electricity Boards. This profile was supported by their high street presence in retail outlets, selling white goods as well as providing for bill collections. Local supply issues would also be dealt with by the Area Electricity Board. Apart from production of the commodity of electricity at power stations and transmitting it between power stations and grid sub stations, the Area Electricity Boards were the only real point of contact between the industry and the general public.
2.3 Further re-organisation
There was a further re-organisation within the nationalised electricity industry in 1972 relating to the level of voltage passing through an electric line. Those lines operating at 132,000 volts were the responsibility of the CEGB until 1972 but then became vested in the Area Electricity Boards. Until 1972 the public could reasonably have perceived all pylon lines as being the responsibility of the CEGB and, as will be explained in Chapter 3, this can make identification of the responsible organisation more difficult.
2.4 Privatisation
The statutory vehicle for privatisation was the Electricity Act 1989. The effective date for the transfer of property and assets to the privatised successors to the Area Electricity Boards was 31 March 1990 and the privatised industry was officially born on 1 April 1990. The legislative background and subsequent statutory developments are reviewed in Chapter 4.
The two main aims of privatisation of the electricity industry were to allow competition between suppliers of electricity and to allow new generators to connect to the system. These aims were prompted by the policy of reducing UK dependence on coal and fossil fuels and the increased availability of gas from the North Sea. No doubt with the life expectancy of many power stations approaching expiry there was an opportunity for private investment in what is inevitably a capital intensive industry. Privatisation was also intended to provide a better deal for customers in opening up this market to competition. Small service companies were able to enter the market; notably for metering and contracting services.
2.5 The emergence of the licence-holder
There are four stages in the supply of electricity to consumers: generation, transmission, distribution and supply. In England and Wales transmission is defined as being the transfer of electricity from the generating plant to a point of distribution at high voltage, which relates to systems operating in excess of 132,000 volts. At voltages below this value, the transfer of electricity between one point and another is known as distribution.
With effect from 1 April 1990 the four main elements of generation, transmission, distribution and supply were split between different companies with specific licences granted by the government and monitored by an appointed regulator.
The generation assets at that time were split between what became National Power and Powergen with the ability of new operators to enter the market.
Transmission assets in England and Wales became the domain of the National Grid Company plc.
England and Wales are divided into 12 distribution areas and responsibility in the respective areas rests with the Distribution Network Operator (DNO). The first DNOs were the Area Boards newly re-named as the local Regional Electricity Company (REC). As at 1 April 1990, therefore, the DNOs and the RECs were one and the same. This is illustrated diagrammatically at Appendix 1 and 2 and in the table at Appendix 3.
Supply was left with the former Area Electricity Boards, then becoming regional licence-holders under their new name of RECs with their licensed areas mirroring the original Area Electricity Board boundaries, as identified at Appendix 1.
Hence it is now necessary to refer to licence-holders and to avoid the term electricity company. We elaborate on the practical consequences below and give the relevant statutory definitions in Chapter 4.
The initial privatisation legislation permitted the same licence-holder to hold both a distribution and a supply licence at one and the same time. This is no longer the case as explained in more detail in Chapter 4.
2.6 Current industry structure
This book is essentially aimed at dealing with transmission and distribution lines across England and Wales. An illustration of how electricity is first generated and is then transmitted and distributed is given at Appendix 4. Distribution lines, being 132,000 volts and below, are the responsibility of the DNOs.
The vast majority of overhead tower lines operate at 132,000 volts on steel lattice towers similar in design but generally lower in height than towers used for the 275,000 and 400,000 volts overhead lines. These lines connect within sub stations to enable power flows to be moved around England and Wales to provide a safe, efficient and economic system. To give an indication of the range and scale of substation installations, within the West Midlands area, with a population of approximately 2 million, there are two sub stations operating at 400,000 volts, nine at 275,000 volts and forty at 132,000 volts.
The responsibility of the DNO ends at the cut out position which is normally immediately prior to the electricity meters. The meters themselves now provide critical evidence for identifying the licence-holder with which you are now actually dealing. In order to change supplier, the MPAN (Meter Point Administration Number) needs to be verified. The reading and verification of meters falls between DNOs and meter companies with a final billing system resting with a range of suppliers. It is the supplier who will pay the DNO for using their system and also pay the generators for the amount of electricity consumed. Understandably there is no direct single link between the generation of electricity and the individual consumer but the collecting and assessment of charges is carried out using the pooling arrangements.3
1 By virtue of The Electricity Reorganisation (Scotland) Act 1954.
2 By virtue of The Electricity Act 1957.
3 The working of the pooling arrangement is beyond the scope of this book but further information can be obtained from the Association of Electricity Producers or the Department of Trade and Industry — Gas and Electricity Division.
3
Electricity Infrastructure
3.1 Types of electricity infrastructure
This chapter concentrates on the varying types of equipment used by the electricity industry expressed in layman’s terms. Brief details will be provided on the following:
- statutory background
- steel lattice towers (pylons)
- alternative metal structures
- wood pole lines
- spacing between supports
- clearances
- tower and pole foundations
- underground cables.
3.2 statutory background
The types of infrastructure used for electric lines in England and Wales are prescribed by a number of statutory instruments supplemented by detailed engineering recommendations and guidelines aimed at maintaining safety both to the public and to employees of and contractors engaged by licence-holders. The Act empowers the Secretary of State to make appropriate regulations. The Electricity Supply Regulations 19881 cover these. Under these regulations the Department of Trade and Industry exercises control over standards through its engineering inspectorate to ensure compliance with the regulations and to report on incidents, particularly fatalities, which occur in relation to electric lines. The Electricity At Work Regulations 19892 provide for the statutory minimum clearances for overhead lines. The regulations governing clearance for overhead lines are supplemented by detailed guidance notes. These clearances vary in accordance with the normal use of the land over which the lines cross and therefore greater clearances are generally required for high speed road crossings and in connection with higher voltage lines. More detailed provisions relating to plant, overhead lines and underground cables are found in the Electricity Safety, Quality and Continuity Regulations 2002.3
The Health and Safety Executive also have detailed guidelines in their brochures GS6 — Avoidance of Danger from Overhead Lines,4 HSG 47 — Avoiding Danger from Underground Services 5 and HSG 141 — Electrical Safety on Construction Sites.6
3.3 Types of overhead line support
Overhead line supports can be constructed of wood, metal or concrete. In other European Countries concrete structures are used but they are rarely encountered in England and Wales. Lower voltage lines, generally up to 33,000 volts, are predominantly supported on wood pole structures and higher voltage lines, including transmission lines, are generally on steel lattice towers, popularly referred to as pylons. Licence-holders adhere to the detailed requirements for the types of support required including the depth of foundations and clearance between conductors. They observe the common specification found in document ESI 43–8, last updated December 1988. This provides comprehensive data on the types of support required to maintain overhead lines of different voltages and in different situations.
A general awareness of the limitations of the types of overhead line helps non specialised professionals to understand why the movement of single supports has a knock-on effect to the remainder of the line. Additionally, the apparently simple solution of replacing a section of overhead line with underground cable could prove to be significantly costly and have co...