NKT – NKT signs final contracts for two HVDC power cable projects in Scotland

EMR Analysis

More information on NKT: See the full profile on EMR Executive Services

More information on Claes Westerlind (President and Chief Executive Officer, NKT): See the full profile on EMR Executive Services

More information on Line Andrea Fandrup (Executive Vice President, Chief Financial Officer, NKT till end of April 2026): See the full profile on EMR Executive Services

 

 

 

More information on SSE Plc.: https://www.sse.com/ + SE is a leading generator of renewables and flexible energy in the GB and Ireland markets, and one of the world’s fastest-growing electricity networks companies.  

This includes onshore and offshore wind farms, hydro, electricity transmission and distribution networks, power stations, carbon capture and hydrogen, solar and batteries, as well as providing energy products and services for businesses and other customers.

SSE’s more than 14,000 employees are dedicated to delivering cleaner, more secure energy and ensuring a just transition to a net zero future. To help us do this, we’re investing around £17.5bn in critical electricity infrastructure across the five years to 2027.

More information on Martin Pibworth (Chief Executive, SSE Plc.): https://www.sse.com/about-us/leadership-and-governance/ + https://www.linkedin.com/in/martinpibworth/ 

 

More information on SSEN Transmission (Scottish and Southern Electricity Networks) by SSE Plc.: https://www.ssen-transmission.co.uk/ + We are SSEN Transmission, the trading name for Scottish Hydro Electric Transmission.

We are responsible for the electricity transmission network in the north of Scotland, maintaining and investing in the high voltage 132kV, 220kV, 275kV and 400kV electricity transmission network.

Our network consists of underground and subsea cables, overhead lines on wooden poles or steel towers, and electricity substations. It extends over a quarter of the UK’s land mass, crossing some of its most challenging terrain.

Our first priority is to provide a safe and reliable supply of electricity to our communities. We do this by taking the electricity from generators and transporting it at high voltages over long distances through our transmission network for onwards distribution to homes and businesses in villages, towns and cities.

Following a minority stake sale which completed in November 2022, we are now owned 75% by SSE plc and 25% by Ontario Teachers’ Pension Plan Board.

More information on Rob McDonald (Managing Director, SSEN Transmission, SSE Plc.): https://www.sse.com/about-us/leadership-and-governance/meet-the-gec/ + https://www.linkedin.com/in/rob-mcdonald-a8b77129b/ 

More information on Sandy Mactaggart (Director of Offshore Delivery, SSE Transmission, SSE Plc.): https://www.linkedin.com/in/sandy-mactaggart-524b35108/ 

 

 

 

 

 

 

 

 

 

 

 

EMR Additional Notes:

• Interconnectors:
  • Interconnectors are high voltage cables that are used to connect the electricity systems of neighbouring countries. They allow us to trade excess power, such as renewable energy created by the sun, wind and water, between different countries.
  • An interconnector (also known as a DC tie in the USA) is a structure which enables high voltage DC electricity to flow between electrical grids. An electrical interconnector allows electricity to flow between separate AC networks, or to link synchronous grids.

 

• HVDC Light:
  • HVDC Light is a modern HVDC (High-Voltage Direct Current) technology that uses Voltage Source Converters (VSCs). It is a successful and environmentally friendly way to design a power transmission system for a submarine cable, an underground cable, using overhead lines, or as a back-to-back transmission.
  • HVDC Light is designed to transmit power underground and underwater, also over long distances. It offers numerous environmental benefits, including “invisible” power lines, neutral electromagnetic fields, oil-free cables and compact converter stations.
  • As its name implies, HVDC Light is a dc transmission technology. However, it is different from the classic HVDC technology used in a large number of transmission schemes. Classic HVDC technology is mostly used for large point-to-point transmissions, often over vast distances across land or under water. It requires fast communications channels between the two stations, and there must be large rotating units – generators or synchronous condensers – present in the AC networks at both ends of the transmission. HVDC Light consists of only two elements: a converter station and a pair of ground cables. The converters are voltage source converters, VSC’s. The output from the VSC’s is determined by the control system, which does not require any communications links between the different converter stations. Also, they don’t need to rely on the AC network’s ability to keep the voltage and frequency stable. These feature make it possible to connect the converters to the points bests suited for the AC system as a whole.
• HVDC (High-Voltage Direct Current):
  • HVDC (High-Voltage Direct Current) is a key enabler for a carbon-neutral energy system. It is highly efficient for transmitting large amounts of electricity over long distances, integrating renewables, and interconnecting grids, opening up new sustainable transmission solutions.
• HVDC Links:
  • The first successful HVDC experimental long distance line (37 miles) was made at Munich, Germany in 1882 by Oskar Von Miller and fellow engineers.
  • HVDC allows power transmission between AC transmission systems that are not synchronized. Since the power flow through an HVDC link can be controlled independently of the phase angle between source and load, it can stabilize a network against disturbances due to rapid changes in power.
  • An HVDC line has considerably lower losses compared to HVAC over longer distances.
  • See the world map of HVDC Links here: https://openinframap.org/#2.45/12.96/62.26
• EHVAC / UHVAC & UHVDC:
  • EHVAC / UHVAC (Extra/Ultra-High Voltage Alternating Current): Refers to electrical power transmission lines that operate at voltages exceeding 220 kV, often between 365 kV and 1000 kV. These lines are used to transmit large amounts of electricity efficiently over long distances.
  • UHVDC (Ultra-High Voltage Direct Current): Refers to a DC transmission system that operates at voltages of 800 kV or higher. Like HVAC, it is designed for transmitting immense amounts of power over vast distances, often exceeding 1,000 km, with minimal losses.

 

 

• Extra Low-Voltage (ELV):
  • Extra-Low Voltage (ELV) is defined as a voltage of 50V or less (AC RMS), or 120V or less (ripple-free DC).
• Low-Voltage (LV):
  • The International Electrotechnical Commission (IEC) defines Low Voltage (LV) for supply systems as voltage in the range 50–1000 V AC or 120–1500 V DC.
• Medium-Voltage (MV):
  • Medium Voltage (MV) is a voltage class that typically falls between low voltage and high voltage, with a common range being from 1 kV to 35 kV. In some contexts, this range can extend higher, up to 69 kV.
• High-Voltage (HV):
  • The International Electrotechnical Commission define high voltage as above 1000 V for alternating current, and at least 1500 V for direct current.
• Super High-Voltage or Extra High-Voltage (EHV): 
  • Super High-Voltage or Extra High-Voltage (EHV) is the voltage class used for long-distance bulk power transmission. The range for EHV systems is typically from 230 kV to 800 kV.
• Ultra High-Voltage (UHV): 
  • Ultra High-Voltage (UHV) is the highest voltage class used in electrical transmission, defined as a voltage of 1000 kV or greater.

 

 

• Fundamental Units of Electricity:
  • Ampere – Amp (A):
    • Amperes measure the flow of electrical current (charge) through a circuit. Ampere (A) is the unit of measure for the rate of electron flow, or current, in an electrical conductor.
      • One ampere is defined as one coulomb of electric charge moving past a point in one second. The ampere is named after the French physicist André-Marie Ampère, who made significant contributions to the study of electromagnetism.
      • Milliampere (mA) is a unit of electric current equal to one-thousandth of an ampere (1mA=10−3A). The prefix “milli” signifies 10−3 in the metric system. This unit is commonly used to measure small currents in electronic circuits and consumer devices.
    • Volts measure the force or potential difference that drives the flow of electrons through a circuit.
      • Kilovolt (kV) is a unit of potential difference equal to 1,000 volts.
    • Watts measure the rate of energy consumption or generation, also known as power.
  • Power vs. Energy: how electricity is measured and billed.
    • Power (measured in kW, MW, GW, TW): Rate at which energy is used or generated at a given moment.
    • Energy (measured in kWh, MWh, GWh, TWh): Total amount of power consumed or generated over a period of time (i.e., Power x Time).
  • Real Power Units: actual power that performs work.
    • Kilowatt (KW):
      • A kilowatt is simply a measure of how much power an electric appliance consumes—it’s 1,000 watts to be exact. You can quickly convert watts (W) to kilowatts (kW) by dividing your wattage by 1,000: 1,000W 1,000 = 1 kW.
    • Megawatt (MW):
      • One megawatt equals one million watts or 1,000 kilowatts, roughly enough electricity for the instantaneous demand of 750 homes at once.
    • Gigawatt (GW):
      • A gigawatt (GW) is a unit of power, and it is equal to one billion watts.
      • According to the Department of Energy, generating one GW of power takes over three million solar panels or 310 utility-scale wind turbines
    • Terawatt (TW):
      • One terawatt is equal to one trillion watts (1,000,000,000,000 watts). The main use of terawatts is found in the electric power industry, particularly for measuring very large-scale power generation or consumption.
      • According to the United States Energy Information Administration, America is one of the largest electricity consumers in the world, using about 4,146.2 terawatt-hours (TWh) of energy per year.
  • Apparent Power Units: measures the total power in a circuit, including power that does not perform useful work.
    • Kilovolt-Amperes (kVA):
      • Kilovolt-Amperes (kVA) stands for Kilo-volt-amperes, a term used for the rating of an electrical circuit. A kVA is a unit of apparent power, which is the product of the circuit’s maximum voltage and current rating.
      • The difference between real power (kW) and apparent power (kVA) is crucial. Real power (kW) is the actual power that performs work, while apparent power (kVA) is the total power delivered to a circuit, including the real power and the reactive power (kVAR) that doesn’t do useful work. The relationship between them is defined by the power factor. Since the power factor is typically less than 1, the kVA value will always be higher than the kW value.
    • Megavolt-Amperes (MVA):
      • Megavolt-Amperes (MVA) is a unit used to measure the apparent power in a circuit, primarily for very large electrical systems like power plants and substations. It’s a product of the voltage and current in a circuit.
      • 1 MVA is equivalent to 1,000 kVA, or 1,000,000 volt-amperes.
  • Specialized Power Units: used specifically for renewable energy, especially solar.
    • KiloWatt ‘peak’ (KWp):
      • kWp stands for kilowatt ‘peak’ power output of a system. It is most commonly applied to solar arrays. For example, a solar panel with a peak power of 3kWp which is working at its maximum capacity for one hour will produce 3kWh. kWp (kilowatt peak) is the total kw rating of the system, the theoretical ‘peak’ output of the system. e.g. If the system has 4 x 270 watt panels, then it is 4 x 0.27kWp = 1.08kWp.
      • The Wp of each panel will allow you to calculate the surface area needed to reach it. 1 kWp corresponds theoretically to 1,000 kWh per year.

 

 

• Power Cable:
  • A power cable is a type of electrical cable used to transmit electrical power. It typically consists of one or more insulated conductors surrounded by a protective outer sheath.
  • Types of power cables:
    • Overhead cables: These are suspended from poles or towers and are commonly used for long-distance power transmission.
    • Underground cables: These are installed underground and are typically used for local distribution or in areas where overhead lines are impractical or unsafe.
    • Submarine cables: These are laid underwater to connect islands, countries, or offshore wind farms to the mainland power grid.
    • Medium-voltage cables: These are used for the distribution of electrical power from substations to local areas.
    • Low-voltage cables: These are used for the final distribution of power to individual homes and businesses.
• Superconducting Power Cable:
  • A superconducting power cable is a type of electrical cable that uses superconducting materials to conduct electricity with zero resistance. This means that no energy is lost due to heat dissipation, making it significantly more efficient than traditional copper or aluminum cables. Superconducting cables can be used to transmit large amounts of power over long distances with minimal energy losses.
• High-Temperature Superconducting (HTS) Cable:
  • High-temperature superconducting (HTS) cables are electrical wires that can carry large amounts of current with no resistance, or energy loss, when cooled to a specific low temperature. Unlike conventional copper cables, they don’t produce heat during operation. The “high-temperature” designation is relative, meaning they can operate at temperatures achievable with the more affordable and abundant liquid nitrogen (~-196°C), rather than the much colder liquid helium required for older, low-temperature superconductors. This makes them a more practical technology for power transmission and other applications.
• Telecommunication Cable:
  • Distinct category of cable with a different primary purpose: transmitting signals rather than power.
  • Telecommunication cables transmit various signals, like voice, data, and video, over distances and include types such as twisted pair cables, which use insulated copper wires for signals; coaxial cables, designed to carry both signals and ground in concentric layers; and fiber optic cables, which transmit data as pulses of light.

 

 

• Grid, Microgrids, DERs and DERM’s:
  • Grid / Power Grid:
    • The power grid is a network for delivering electricity to consumers. The power grid includes generator stations, transmission lines and towers, and individual consumer distribution lines.
      • The grid constantly balances the supply and demand for the energy that powers everything from industry to household appliances.
      • Electric grids perform three major functions: power generation, transmission, and distribution.
  • Microgrid:
    • Small-scale power grid that can operate independently or collaboratively with other small power grids. The practice of using microgrids is known as distributed, dispersed, decentralized, district or embedded energy production.
  • Smart Grid:
    • Any electrical grid + IT at all levels.
  • Micro Grid:
    • Group of interconnected loads and DERs (Distributed Energy Resources) within a clearly defined electrical and geographical boundaries witch acts as a single controllable entity with respect to the main grid.
  • Distributed Energy Resources (DERs): 
    • Small-scale electricity supply (typically in the range of 3 kW to 50 MW) or demand resources that are interconnected to the electric grid. They are power generation resources and are usually located close to load centers, and can be used individually or in aggregate to provide value to the grid.
      • Common examples of DERs include rooftop solar PV units, natural gas turbines, microturbines, wind turbines, biomass generators, fuel cells, tri-generation units, battery storage, electric vehicles (EV) and EV chargers, and demand response applications.
  • Distributed Energy Resources Management Systems (DERMS):
    • Platforms which helps mostly distribution system operators (DSO) manage their grids that are mainly based on distributed energy resources (DER).
      • DERMS are used by utilities and other energy companies to aggregate a large energy load for participation in the demand response market. DERMS can be defined in many ways, depending on the use case and underlying energy asset.

 

 

• Commissioning:
  • Commissioning ensures the system not only works but also works efficiently and effectively to meet its intended purpose. It is a quality assurance process that ensures a newly installed system is designed, installed, tested, and maintained to operate according to the owner’s requirements.
  • It goes beyond a simple installation. Commissioning is a formal, documented process that involves several key steps:
    • Pre-Installation
    • Installation Verification.
    • Functional Performance Testing.
    • Documentation & Training.