Reactive Power Report

How better grid management can accelerate and smooth the UK's journey to Net Zero 2050

Overview

The UK is on its way to meet our ambitious target of reaching net zero by 2050. However, as we move towards a decarbonised energy network, with an increasing proportion of our heat and transport fuelled by asynchronous generation such as renewables, we must consider the effect this will have on the level of reactive power produced and how this will impact the stability of our grid.

Active and reactive power play a crucial role, not only in the power grid but across many industries and sectors. However, the UK will face several challenges over the coming years in relation to reactive power, especially as we move towards net zero targets.

This report sets out the ‘Reactive Power Challenge’, identifying how better grid management can accelerate and smooth the UK’s journey to net zero 2050.

What is reactive and active power?

Across the UK’s power grid exist two types of power: reactive power and active power. Whilst reactive power helps to run motors and transformers as well as controlling the voltage across the grid, active power is what is used to run our day-to-day electrical appliances, such as lightbulbs and phones.

How does it work?

Reactive and active power can be illustrated with the analogy of a boat, sailing across a body of water; although it is the wind (or active power) pushing the boat, it is the water (or reactive power) keeping the boat afloat. Regardless of the strength of the wind, if there were not enough water, the boat would not be able to move.

Reactive power works in this way. The amount of reactive power in our grid must be balanced and managed very carefully. Too much reactive power and the voltage on the grid goes up to an unsafe level. But too little reactive power and there’s not enough to push active power to where it needs to be.

How is it created?

All forms of power generation produce active power, including renewable power sources. However, reactive power is produced at scale by synchronous generators in gas, coal, hydro and nuclear power stations. These power stations use heavy spinning turbines to generate electricity, including reactive power. Some kinds of renewables, such as certain types of windfarms, are not able to produce reactive power, whilst the inverters in solar parks can produce a limited amount of it.

Why does reactive power matter?

Reactive power is needed to operate equipment such as motors. Without it, the machinery, industrial and manufacturing facilities that we all depend on in everyday life cannot work, as active power alone is not able to spin these motors.

Many other consumer-facing sectors such as retail, leisure and hospitality, and healthcare services also rely on turbines and motors and therefore also rely on reactive power. Many of the fundamentals of day-to-day life such as lifts, escalators, refrigerators, and fans need reactive power to help power their spinning motors.

Where there is a weaker grid, with a reduced ability to regulate its voltage, industrial users will end up paying more as they will be required to adapt their connection network to ensure it works efficiently and within the normal values. This means adding additional electrical systems such as compensation equipment.

Above all, reactive power is vital to control and compensate voltage fluctuations of the grid – which can be harmful for efficiency and, in the worst cases, can make the grid unstable.

Many other consumer-facing sectors such as retail, leisure and hospitality, and healthcare services also rely on turbines and motors and therefore also rely on reactive power. Many of the fundamentals of day-to-day life such as lifts, escalators, refrigerators, and fans need reactive power to help power their spinning motors.

How can we help balance the grid?

The national picture of our power mix and use is changing but unlike active power, reactive power cannot travel far. This means that reactive power needs to be managed on a regional level, and ‘balanced’ to make sure the right amount is on the grid.

Historically, balancing has been easier because synchronous power stations can be controlled to produce reactive power as they generate active power, and they can also absorb reactive power when needed. This has been a cost-effective way of managing the grid when distributed or “embedded” generation wasn’t necessary.

However as more asynchronous, renewable power comes on the grid, making the production and absorption of reactive power more difficult. 

The result is that National Grid and the Distribution Network Operators (DNOs) have had to find new ways to balance reactive power. In addition to making the market for balancing services more efficient and transparent, it is vital to future-proof the grid’s physical infrastructure by making better use of innovative and less expensive assets.

Although cables have traditionally been used to simply move electricity from one area to another, today British engineering is opening the possibility of cables deep beneath our feet being used for much more in support of decarbonisation.

By balancing the contribution of capacitors and inductors in the cables and wires that form the electrical grids, both reactive and active power can flow through the cables and move more smoothly around the grid.

Enertechnos’ industry leading cable has been designed to provide this essential balance. Through its patented technology, the cable acts as a capacitor, and provides capacitive reactance, which offsets most of the inductive reactance of the cable itself. Furthermore, and for this same reason, CTS cables have a reduced voltage drop. This supports the transportation of reactive power across the grid. This means Enertechnos’ cable will make better use of the reactive power that we have on the grid and will allow us to manage reactive power across regions, which is becoming more necessary as renewables come into the grid and reactive power becomes scarcer.

By investing in the best available infrastructure today we will guarantee the long-term sustainability of electricity supply and resilience of the grid as we transition to net zero.

By balancing the contribution of capacitors and inductors in the cables and wires that form the electrical grids, both reactive and active power can flow through the cables and move more smoothly around the grid.

Download the report to read more about reactive power or get in touch by emailing info@enertechnos.com