Untitled Notes

Topic encompasses the fundamental aspects of electricity transmission and distribution.

Hierarchical Structure of Voltage Levels:
- 400 kV
- 275 kV
- 132 kV
- 33 kV
- 11 kV
- 415 volts
- 230 volts
Transmission involves high-voltage lines that carry electricity over long distances, while Distribution refers to the lower-voltage lines that deliver electricity to homes and businesses.

The UK National Grid dates back to 1925 with the formation of the Central Electricity Board (CEB).
Objective: To create a “national gridiron” to efficiently supply electricity across Britain.
1935: Seven key locations were selected to form the backbone of this interconnected network; control rooms established at each site.
1937: Successful testing linking all seven grid locations, marking the operational launch of the National Grid.

By the late 1940s, electricity demand surged beyond expectations, leading to inadequacies in the existing 132 kV lines.
The electricity supply sector was mainly dominated by 569 small companies, predominantly local authority-run, accounting for two-thirds of electricity sales.
The Electricity Act 1947, effective from April 1, 1948, nationalised the electricity supply in Great Britain:
- Established the British Electricity Authority (BEA) to manage the electricity grid.
- BEA controlled generation and transmission, while Area Boards managed distribution and sales.
Plans were initiated for a new high-voltage grid operating at 275 kV, with future potential to upgrade to 400 kV.

Original Supergrid designed around conventional coal-fired power stations in the Midlands, facilitating North-South power flows to urban areas.
Current trends indicate an evolution toward accommodating renewable energy sources, particularly from offshore wind farms in the North Sea.
The National Grid is progressing towards a next-generation Supergrid to support the UK’s Net Zero targets.

August 27, 1957: Sellafield in Cumbria began operations as the first full-scale nuclear power station in the UK (and the Western world), contributing to the national grid for nearly 50 years before its closure in 2003.

The existing electricity grid faces capacity challenges due to the anticipated surge in offshore renewable energy.
The UK is urged to enhance its electricity grid systems urgently, in preparation for an increase in demand and the shift towards decarbonisation, decentralisation, and digitalisation.
- An estimated four times more transmission infrastructure must be constructed in the next seven years than the amount installed since 1990.

Visual representation (Flow Diagram) inclusive of key voltage lines, offshore wind projects, and existing circuits.

National Grid is set to expedite up to 20 GW of grid connections, equivalent in capacity to six Hinkley Point C nuclear reactors.
Hinkley Point is recognized as Europe's largest construction site with ongoing development of two new nuclear reactors.

Transmission Lines: High-voltage electricity over long distances.
Distribution Lines: Lower-voltage electricity over shorter distances to consumers.

Provides licensing for electricity generation and supply in England and Wales.
Section 10, Schedule 3 grants powers to license holders:
- Acquire land and rights over land for distributing electricity (not for any other purpose).

Some landowners prefer a capital sum for an easement over annual wayleave payments, giving up rights to terminate.
Certain companies like National Grid now offer only easements.

Schedule 3 Part 1 establishes protocols for acquiring land or rights via agreement, involving standard documents that outline terms and conditions for installation.

If mutual agreement is unattainable:
- A formal notice is served requiring a wayleave within 21 days.
- If not granted, an application for compulsory purchase order is submitted to the Secretary of State, typically for land related to substations.

Historical context on high-voltage overhead line placement in relation to urban developments.
Developers often seek to relocate overhead lines, but National Grid expresses preference to retain lines due to environmental and cost considerations.

Current international scientific evidence does not support any causal relationship between EMFs from high voltage power lines and health issues such as cancer.
No special government precautions regarding home development near power lines are recommended based on EMF evidence.

Methods include ploughing and directional drilling for the installation of low voltage lines.

Typical spacing is 365m.
Various pylon designs discussed:
- Conventional lattice: Height typically 40m-50m.
- Low-height lattice: Height typically 38m-41m.
- T-pylon: Height typically 35m-38m.

Tunnel dimensions and construction methods are outlined for underground cable installations, including necessary ventilation and emergency access points.

Established by the Planning Act 2008 for projects categorized as Nationally Significant Infrastructure (NSIP).
- DCOs govern construction and maintenance permissions for energy, transportation, and water projects.
- Planning Inspectorate manages applications, examining public opinions and evidentiary support before presenting recommendations to the Secretary of State for decision making.

Pre-Application: Public consultations are conducted.
Acceptance: Application is received and verified by the Planning Inspectorate.
Examination: Detailed evidence review over six months.
Recommendation and Decision: Report issued to Secretary of State for approval or rejection.
Post Decision: Period for judicial reviews is allowed for six weeks post-decision.