The strength and stay of the UK energy system

This week, Queen Elizabeth became the third longest reigning monarch in history. For 70 years she has steadfastly maintained her position and despite what you may think about the role of the Monarchy in modern Britain, she has seldom put a foot wrong. It is almost inconceivable to imagine the changes she has seen over her long life.

Queen Elizabeth’s coronation was one of the first live televised events beamed across the Commonwealth. Whole villages crowded into packed community halls and families sat in lounge rooms to watch the first grainy images flicker across the screen of her walking down the isle of Westminster Abbey.

When the young queen ascended the throne, how information was transmitted was vastly different to how it is today. How and when public figures such as the Queen and politicians were able to speak to the masses was largely one-way and dictated by the morning papers and the evening news. The two-way exchange of ideas or interactions would come much later. Talkback radio was still about a decade away and the quick exchanges on social media platforms was another five.

During her reign there has been periods of great change. Just as information sharing has shifted from a one-way dialogue to a two-way exchange through social media, so to has the energy grid. Instead of a one-way flow of electrons, the grid must now support a two-way flow of energy as we decarbonsise and move to net zero.

70 years ago – and for one hundred years before that – energy production and dispatch had been much the same; a one-way flow of energy into Britons’ homes and businesses. Coal was king and easily and cheaply sourced from England’s resources-rich north. In fact, by the time the coal mining industry was nationalised  in 1946, 90 per cent of the United Kingdom’s electricity was produced from coal.

The makeup of the UK energy mix stayed that way (except for a short foray in nuclear energy in the 50s) until the 90s, when emerging new technologies such and wind and solar entered the fray.

In what is now a very different Britain from the one the Queen ascended the throne in, the UK energy sector has been invigorated by the recent commitments to reach net zero carbon emissions by 2050 (2045 in Scotland) and a fully decarbonised electricity system by 2035.

And like the ‘modern monarchy’, the United Kingdom’s energy sector must move with the times.

A recent report from Catapult Energy System in the UK, recognised while work is underway to facilitate the near-term replacement of fossil-fuelled generation with renewable technologies, less attention is given to the end state – the operation of a fully decarbonised power system that supports the two-way flow of energy from solar, wind, distributed energy resources (DER) and even the new kid on the block – electric vehicle integration.

While various white papers, targets and commitments create clarity and certainty about the direction of decarbonsiation, they also highlights the need for the sector to create and deliver a practical plan for the entire power system.

The scale of change required in power system planning and operational practices is unprecedented. There is a need to identify the challenges and opportunities that a fully decarbonised system will create; how they can be managed; and the key decision points in the transition.

While the report itself is designed to be starting point to discussion and debate, it is clear in its intention that a fully decarbonised grid is essential and urgent.

Key findings

Flexible demand

In a net zero power system, flexible demand could be shifted to meet available renewable generation, rather than dispatching generation to meet demand.

Today demand is mostly predictable, and generation is dispatched to meet it. In a net zero system, generation and demand will be more weather dependent and there will be new opportunities for flexible demand, e.g., battery charging, EV charging, heat pumps and hydrogen production, to be dispatched to use renewable generation when it is available.

A net zero system will no longer have access to bulk stored energy in the form of fossil fuels and security of supply will need to be achieved by alternative sources.

Consumers will become more dependent on their electricity supply due to increased electrification and demand will become more weather dependent. Securing supply during periods of high demand and low renewable output, e.g., a cold winter, will require new forms of storage spanning months and years.

Digitalisation and data

Digitalisation and enhanced data will provide an opportunity to use dynamic approaches to operability and move away from deterministic rules.

Today a set of deterministic rules are used for system operation. Increasing data collection and using more sophisticated tools will provide the opportunity to use dynamic operability parameters in real time, e.g., dynamic assessment of the risk of network faults.

Technological and societal changes

Devices like Electric Vehicle (EV) chargers and heat pumps could support system operation by automatically and autonomously responding to frequency and voltage.

Net zero system operation can be supported by devices, such as EV chargers and heat pumps, by enabling them to respond to frequency and voltage signals. This would facilitate an automated response without the need of central control.

The technological and societal changes that come with net zero present opportunities for different standards and approaches to operability.

System operation is a product of the physical characteristics of the network, what is connected to it and the standards expected from it, e.g., security of supply. Societal, technological and political choices will interact with each other and influence how the system is operated.

Storage

There will be many possible roles for energy storage in a net zero system. The cost will depend on several interacting technical factors including size, duration and how often it is used.

Storage costs will depend on technological characteristics, like whether costs scale with power (MW) capacity or energy (MWh) capacity, and roundtrip efficiencies. How the storage is used, and how often it “cycles” will be very important in determining its levelised costs. Storage that cycles very infrequently might cost £1,000s or even £10,000s per MWh.

Further research is essential to stress test the power system, the modelling and economics of flexible demand, energy markets and the requirements for and cost of storage in a net zero system.

Research and innovation are ongoing across the whole energy sector, which will contribute to reaching net zero. Further suggested research includes:

• “Stress testing” the system against extreme events, e.g., long periods of low wind.

• Interactions between weather and energy demand and the impact on demand flexibility from heat and transport.
• The economics of demand side flexibility to support investment, policy, operational decisions and impact on customers’ comfort and wellbeing.
• Net zero electricity system and alignment of electricity markets
• The requirements for, and cost of, storage within a net-zero system.

The reign of Queen Elizabeth will be an enduring legacy in Britain’s history books. So too will the decisions made today shape the future of Britain energy grid and become an enduring legacy in the transition to net zero.

Investment, social and technical decisions made today will form part of the net zero system and it is therefore crucial to understand and assess their impact.