What does a substation engineer actually do?
There are two broad kinds of job. The site engineer looks after plant that is already live or being built: testing, maintenance, fault finding, refurbishment and commissioning. The design engineer works mostly in an office and turns a planned network change into drawings a contractor can build. Many people move between the two over a career, and the job titles vary from one network company to the next.
On the site side, a qualified engineer at National Grid leads fitters and contractors on high voltage jobs. That means writing risk assessments and method statements, running toolbox talks, checking safety critical work and acting as principal contractor and temporary works co-ordinator under the CDM Regulations. Expect a standby rota for emergency call outs. Transmission roles at SSE also involve reviewing contractor designs, witnessing factory acceptance tests and evaluating tenders.
Primary and secondary design
Primary design deals with the physical layout of the substation. You arrange plant, equipment and structures to fit the site and meet statutory clearances, and you select conductors and connectors. You build up a picture of the existing site from archive records, surveys and old standards, then add the new or replacement kit. At the transmission end, the work includes outline scopes, site plans and single line diagrams.
Secondary design covers protection and control. You specify equipment, produce or adapt schematics, wiring diagrams and schedules, and keep the operational drawings up to date. The hard part is usually making new equipment talk to old equipment, which takes patient detective work. National Grid Electricity Distribution's team in Bristol designs substations up to 132kV, works mainly in AutoCAD and also calculates and issues protection settings.
Safety rules and authorisation
You do not work on a network operator's HV system just because you are qualified. Each company writes its own safety rules, and distribution companies base theirs on the Energy Networks Association's Model Distribution Safety Rules. Under that model, every grade of person is appointed in writing by the company. A Competent Person can receive and clear certain safety documents. An Authorised Person is an experienced Competent Person given specific duties, which can include issuing Limitations-of-Access.
A Senior Authorised Person can issue and cancel safety documents such as the Permit-to-Work and Sanction-for-Test. Becoming a SAP is the main milestone for a site substation engineer. National Grid's training for the role mixes site work with courses at its Eakring site in Nottinghamshire. Your authorisation belongs to that employer and its system, so if you change company you should expect to be assessed again.
Why demand is growing
The grid needs a lot more substation capacity. National Grid's Great Grid Upgrade is made up of 17 major infrastructure projects across England and Wales. It is linked to the government's aim of connecting an extra 40GW of offshore wind by 2030, which would take the total to 50GW. Ofgem's final determinations for the RIIO-ET3 price control say transmission could need more than £70bn of investment over the period. That is why design offices and regional site teams keep recruiting.
Pay
GBP a year, before tax. These are modelled figures for power and utilities roles, based on ONS Annual Survey of Hours and Earnings April 2026 (provisional) data and uprated with a wage index. The regional rows are modelled, not official. Recent adverts give a sense of real offers: National Grid paid £47,442 to £49,000 during training and £57,163 at SAP, and SSE advertised £50,100 to £75,100 for transmission roles. Standby, call outs and overtime add to base pay. Refer to the Power & Utilities salary guide for figures from live adverts.
What you need
- Technical qualificationSite roles at National Grid ask for at least NVQ Level 3 or an ONC in electrical or mechanical engineering. Design roles usually want a national certificate or higher in electrical engineering.
- Degree for graduate schemesNational Grid's graduate substation scheme asks for at least a 2:2 in a degree built on electrical principles, such as electrical engineering, power systems or electronics.
- Practical skillsYou need to be able to read electrical schematics, use test equipment, interpret maintenance results and write risk assessments and method statements.
- Company safety authorisationYour employer appoints you in writing under its own safety rules, starting as a Competent Person and working up to Authorised Person and then Senior Authorised Person.
- Driving licenceSite and design jobs both ask for a full UK driving licence, because you travel between substations across a region.
- Living near the patchStandby roles often require you to live within about 30 minutes of the area you cover so you can respond to call outs.
- Legislation awarenessTransmission employers expect you to understand the CDM Regulations and the Electricity Safety, Quality and Continuity Regulations.
How to get there
- StartPick a route inSchool leavers can take an advanced apprenticeship such as Power Industry Substation Fitter Level 3, or the Electrical Power Networks Engineer Level 4 higher apprenticeship. Graduates can apply for network company graduate schemes.
- Year 1-3Apprenticeship or collegePower industry apprenticeships can take up to three years and mix work on the job with off-site study. The college route covers engineering or electrical engineering courses.
- Year 3-5Join a substation training programmeWith NVQ Level 3 or an ONC and industrial experience, you can join a regional team and spend 18 to 24 months on training at work and in the classroom.
- Year 5 onwardGain SAP authorisationOnce you are authorised as a Senior Authorised Person, you can issue safety documents, lead site teams and join the standby rota.
- Mid-careerMove into design or projectsSome engineers move into primary or secondary design, or into transmission project roles that involve design review, factory acceptance testing and tendering.
- LaterProfessional registrationSenior transmission roles often prefer a Chartered Engineer, or someone working towards it with a relevant institution.
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Questions people ask
Do I need a degree to be a substation engineer?
Not for site roles. National Grid's site substation engineer jobs ask for at least NVQ Level 3 or an ONC along with practical industrial experience. A degree with a 2:2 or better gets you onto graduate schemes, and senior transmission design jobs usually want a degree or HND.
What is a Senior Authorised Person?
Under the ENA Model Distribution Safety Rules, a Senior Authorised Person is an Authorised Person appointed in writing by the network company to issue and cancel safety documents such as a Permit-to-Work. On site it is the key authorisation, because it lets you make HV plant safe for other people to work on.
Can an industrial or maintenance electrician become a substation engineer?
Yes, if you have a Level 3 qualification and hands-on experience installing, repairing and maintaining equipment. National Grid recruits people like that into an 18 to 24 month training programme that ends with SAP authorisation.
Is substation design office work or site work?
Mostly office work. You visit sites for surveys and inspections. At National Grid Electricity Distribution, designers are based in Bristol, work in AutoCAD and travel around the region when a job needs it.
Does the job involve call outs?
Site roles usually do. Engineers join a standby rota for emergency faults and are paid a standby allowance and a call out fee, and employers often ask you to live within about 30 minutes of your area.
What is the difference between primary and secondary design?
Primary design covers the physical layout, clearances, conductors and connectors of a substation. Secondary design covers protection and control: schematics, wiring diagrams, schedules and protection settings.
Sources
- National Grid Electricity Distribution: Substation Electrical Design Engineer
- IET Engineering Jobs: National Grid Substation Engineer, Port Talbot
- National Grid: Graduate Substation Engineer, South West (Chiltern)
- DWP Find a job: SSE Substation Engineer
- Energy Networks Association: SHE Standard 07 Model Distribution Safety Rules 2022
- National Careers Service: Electricity distribution worker
- National Grid: The Great Grid Upgrade
- Ofgem: RIIO-3 Final Determinations overview
