How nuclear and renewable energy could work together in the UK

Nuclear reactors could generate useful heat and produce green hydrogen as well as electricity – and thus play a major role in decarbonisation efforts – if the role of civil nuclear power in the energy mix could be reconsidered. Professor Zara Hodgson, Director of the Dalton Nuclear Institute at the University of Manchester, explains how.

Getting to net zero by 2050 is going to rely upon a Herculean effort in every part of our energy system. The recent NESO report shows that fact very clearly, highlighting the step changes needed across all parts of the energy landscape to get to a clean electricity grid by the end of this decade, with decarbonisation of other sectors to follow.

For a long while, nuclear and renewables have been seen as competing for policy attention, funding and resources, yet their trajectories in recent decades have been markedly different.

The expansion of renewable energy in the UK has successfully displaced fossil fuel-burning power plants, bringing the ambition of reaching entirely clean electricity production within the next decade within the realms of possibility. On the other hand, we have seen only one new nuclear plant brought online since the 1980s (Sizewell B), with only one other (Hinkley Point C) under construction today. The nation’s share of nuclear electricity has declined – and will continue to do so for a while to come.

To the modern observer, nuclear power has become associated not only with its baseload generation, but also high capital costs and construction delays. These attributes have made it appear inflexible in balancing the variable demands of the grid. It’s equally well established that renewables embody an element of variability and unpredictability. After all, weather forecasting is a stereotypically British hobby! These issues bring challenges relating to financing, building and operation of our overall energy system.

To date, the back-up plan for our changeable weather has been the installation of natural gas-burning power plants and energy storage. This is despite the drawbacks of high-cost electricity from gas plants only used at peak times, wasted energy from curtailment of renewables, and the continued generation of CO₂ emissions.

Is there a way to look again at nuclear?
We at the Dalton Nuclear Institute asked ourselves if there was a way for Great Britain to look again at how nuclear electricity – and importantly also nuclear heat – could help to accelerate the renewable energy technology-led transition to net zero, whilst also underpinning UK leadership in combatting climate change.

The work done by my colleagues – involving detailed modelling of a potential 2050 UK energy system – has illustrated that there is a more efficient way to address the challenge of meeting the variable demands of a carbon-free economy than the current approach. Furthermore, this can be achieved at lower overall cost and with more UK jobs than currently envisaged – and without resorting to the use of fossil fuels for back-up power.

This is achieved by exploring a fundamental change in how nuclear energy is modelled to operate in the system. Instead of simply being used for baseload production of electricity, a fleet of nuclear reactors – large, small and advanced – is envisaged as producing a flexible combination of high-quality heat, hydrogen and electricity, along with deployment of associated energy storage.

We put forward a different potential energy future, to spark further discussion. Our proposal is a maximal scenario for electrification – over 840 TWh total supply – three-quarters of which is supplied by renewable energy, just 10% by nuclear plants and zero from fossil fuels. Clearly, such a large-scale approach to clean energy requires a hugely demanding build programme of both new renewable and nuclear infrastructure, in terms of pace and scale.

We consider the potential of a fleet of nuclear reactors – large, small and advanced – to produce a flexible combination high-quality heat, hydrogen and electricity, along with deployment of associated energy storage.

Much of the nuclear capacity would also likely have to be sited closer to energy end users, to enable co-generation to be effective.

There would also need to be developments in grid design and management to trade and balance the supply and demand of electricity, heat and hydrogen. Along with the development of more sophisticated markets for heat and hydrogen as energy vectors, alongside electricity.

However, the benefits that could be realised – not least energy independence and savings of up to £14bn/y on the current UK energy system scenario – merit attention and analysis. Importantly, these benefits are scalable; the full implementation of this very ambitious approach is not required to make it financially and environmentally attractive.

Looking at the full picture
We have recommended that, instead of modelling renewables, nuclear, heat and hydrogen in siloed or outdated strategies, government take more holistic and innovative approaches to energy systems modelling – looking at the full picture.

Capitalising on the flexibility of nuclear energy to contribute more than just low-carbon electricity is a key innovation opportunity for Great Britain. A transition to net zero that integrates electricity generation, from both renewables and nuclear, along with nuclear-enabled heat and hydrogen production, must be explored.

The time to research, evaluate and plan for the delivery of Great Britain’s clean energy future is now.

The views and opinions expressed in this article are strictly those of the author only and are not necessarily given or endorsed by or on behalf of the Energy Institute.

• Further reading: ‘Nuclear share in global energy generation falls to lowest level in four decades’. The share of nuclear power in global gross electricity generation fell below 10% last year, its lowest level since the 1980s, according to a new industry report.
• While the focus on 2030 clean power targets for the UK is important, we must also consider what happens beyond that – intergenerational equality demands it, according to Dr Philip Rogers, Director of nuclear consultancy and project developer Equilibrion.