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New Energy World magazine logo
New Energy World magazine logo
ISSN 2753-7757 (Online)

Addressing capacity constraints in the UK energy transition

3/7/2024

8 min read

Barge with yellow equipment for installing pipes floating in calm water with hills in background Photo: National Grid
Interconnectors aren’t the entire solution. This is one of the specialist barges used to construct North Sea Link, which connects Blyth, Northumberland, to the Norwegian village of Kvilldal.

Photo: National Grid

The UK is facing daunting challenges on the cusp of the energy transition. As the UK phases out ageing nuclear reactors and plans the closure of its final coal-fired power station, there is potential for a substantial shortfall in baseload electricity generation capacity. Gavin Bollan, Technical Director at consultancy ITPEnergised, explores the pressing issues accompanying the transition.

Due to the age of many of the UK’s nuclear facilities, the government is in the process of decommissioning older sites, which will soon strip about 5–6 GW of stable base-load power from the British grid. With many of the UK’s power stations being decommissioned during the next decade, other sources of renewable energy may not be able to ensure sufficient supply, meaning we will need to use more gas-fired generation capacity. Simultaneously, the cessation of coal-fired power, while aligning with our environmental objectives, heightens the capacity gap.

 

The UK’s transition from these traditional power sources will require significant investments in new technologies and infrastructure to ensure a stable energy supply.

 

When you combine these scenarios with the current state of the UK nuclear fleet, there is great cause for concern. Five of the UK’s nuclear power stations are currently generating electricity, while three are in the defuelling phase – the last stage of their operational lifecycle before decommissioning.

 

It might be possible to partially replace this baseload energy loss with offshore wind power, but offshore wind power is inherently intermittent. The variability of wind necessitates large-scale energy storage systems and significant upgrades to the UK grid infrastructure, both of which are currently limited and costly to implement.

 

Economic costs, environmental impacts, policy uncertainty and the need for coordinated planning further complicate reliance on offshore wind alone. Thus, a balanced energy strategy incorporating a mix of renewable sources, advanced storage solutions and grid enhancements is essential to ensure a reliable and sustainable energy future.

 

The UK government has set ambitious targets for wind energy and hydrogen production. Specifically, the aim to develop 10 GW of hydrogen capacity by 2030, although more recent discussions suggest 6 GW might be more realistic.

 

This goal necessitates an equivalent increase in electricity generation, primarily expected to be met through offshore wind. However, as of last year, less than 8 GW of offshore wind capacity were under construction and the government’s approach to pricing saw zero entrants for last year’s Allocation Round (AR). This has since been partially recovered in this year’s AR but was a further backwards step at a time it could be ill-afforded. This significant discrepancy raises serious doubts about the UK’s ability to meet hydrogen targets and reflects broader concerns about the scalability and rapid deployment required for wind energy to meet national needs.

 

The dual role of hydrogen
Hydrogen plays a pivotal role in the UK strategy for a cleaner energy future, presenting unique challenges and opportunities. Hydrogen’s role should be seen as not just a fuel but also as an essential component in energy storage. By converting excess wind energy into hydrogen during peak production times and then utilising it to generate electricity during periods of low wind, the UK can potentially mitigate some of the inherent issues associated with renewable sources, thereby enhancing UK grid stability.

 

In fact, there has been an ‘explosion’ in battery energy storage systems (BESS) in recent times, and these are useful to help balance the grid in the ultra-short term – for hours rather than days during lulls in renewable energy generation. These, in turn, need recharging, and the length of time required can change, depending on the size of the battery and the available grid supply. With the right precautions, hydrogen can be stored long-term, which makes it attractive as an energy source when renewables are not producing and the BESSs have all discharged. 

 

There are several interesting applications. Emerging electrolyser technologies will allow for ‘reversible operation’: with the ability to produce hydrogen when electricity is available, and go into reverse to operate as a fuel cell to generate electricity from hydrogen when needed. Several UK gas-fired power stations are considering converting to partial or even full hydrogen capability, using hydrogen as a like-for-like fuel, swapping out methane (natural gas).

 

Embracing electrification
The shift away from traditional gas heating and power generation, towards technologies such as heat pumps and electric vehicles (EVs), adds further complexity to our energy scenario. While beneficial for reducing carbon emissions, these technologies increase the demand for electricity and competition for the emerging hydrogen industry. There is a significant gap in the UK’s current energy policy, which fails to integrate these technologies with the necessary infrastructure advancements and rapidly changing electricity generating profile.

 

There are other electric heating systems available, but none are as efficient as heat pumps. Considering these weaknesses, the need for a revitalised push for energy efficiency and insulation, micro-generation (such as solar panels on new housing), and significant investments in battery storage solutions are essential steps towards developing a cohesive energy policy that works for all.

 

In addition, the UK faces significant supply chain risks that could hamper the energy transition. For example, while the nation currently has only 4,000 trained heat-pump installers, it is estimated by the Heat Pump Association that we will need 33,000 by 2028 to meet growing demand. This gap highlights a critical bottleneck in the adoption of energy-efficient heating systems.

 

Furthermore, the infrastructure for EVs is under strain, with long waits for the installation of EV chargers becoming increasingly common. Securing planning permissions for new energy projects and upgrading existing infrastructure add another layer of complexity. These supply chain issues must be addressed alongside capacity constraints to ensure a smooth and timely transition to a sustainable energy future.

 

The role of interconnectors
Interconnectors play a vital role in balancing supply and demand across borders. During peak demand periods in the UK, energy can be imported from countries with surplus capacity, such as France or Norway. France, with its extensive nuclear power fleet, often has excess electricity, making it a reliable source. Similarly, Norway’s abundant hydroelectric power offers a stable and renewable energy supply. This cross-border energy exchange helps mitigate the risks associated with sudden spikes in electricity demand or unexpected drops in renewable energy generation.

 

Renewable energy sources like wind and solar offer significant variability in power generation due to their reliance on environmental factors. Interconnectors help manage this variability by allowing excess renewable energy generated in one country to be exported to another. For example, on particularly windy days the UK can export surplus wind-generated electricity to neighbouring countries, ensuring that this renewable resource is utilised efficiently rather than being wasted.

 

While interconnectors enhance energy security by providing access to a broader energy market, they also introduce certain vulnerabilities. Dependence on external energy supplies can expose countries to geopolitical risks and market fluctuations. For example, disruptions in interconnector cables, whether due to technical failures or geopolitical tensions, can lead to significant supply shortfalls. The fire at the UK end of the main French interconnector in 2021, which caused a substantial reduction in available electricity, is a case in point. Such incidents underscore the importance of maintaining and protecting these critical infrastructures.

 

Despite their benefits, interconnectors are not a panacea. They complement but do not replace the need for robust domestic energy policies and infrastructure. The UK, for example, continues to invest in its renewable energy projects, battery storage systems and alternative technologies like hydrogen to enhance energy self-sufficiency. Interconnectors, while vital, are part of a broader strategy to create a resilient, low-carbon energy system.

 

Despite their benefits, interconnectors are not a panacea. They complement but do not replace the need for robust domestic energy policies and infrastructure.

 

Developing a comprehensive energy strategy
As we address these multifaceted challenges, the development of a comprehensive and adaptable energy strategy becomes crucial. This strategy must expedite the deployment of renewable energy sources while also enhancing the grid’s flexibility and resilience to manage fluctuating supply and demand.

 

We know that BESSs can only act as a short-term solution at best when wind turbines are not producing enough energy, leaving us relying on our gas capacity or interconnectors with overseas energy providers. This will become increasingly important given the predicted rise in the UK’s population and gradual electrification of heat and mobility – as energy demand will increase over the next decade.

 

The need for a pragmatic approach that balances the UK’s ambitious renewable targets with the realities of technological and infrastructural limitations is key. Through informed strategies and innovative solutions, we can navigate our way to a reliable and efficient energy system that works for all.