Written evidence submitted by Prof. David Brayshaw, Professor of climate science and energy-meteorology, University of Reading, Prof. Konstantinos Chalvatzis, Professor of Sustainable Business, University of Exeter, Prof. Chris Dent, Professor of Industrial Mathematics, University of Edinburgh, Prof. Amanda Maycock, Professor of Climate Dynamics, University of Leeds, Assoc Prof. Sarah Sparrow, Associate Professor in Environmental Impact, University of Oxford, and Prof. David Wallom, Professor of Informatics, University of Oxford (NPE0031)

The following remarks are made in response to the “call for evidence” relating to the three updated National Policy Statements for energy infrastructure (EN-1, EN-3, EN-5).  Due to time constraints (only becoming aware of this call for evidence shortly before the call closed), these comments are made on the basis of only a partial read of the EN-1, EN-3 and EN-5 documents.  They are, however, informed by considerable research experience working at the interface of energy- and climate and we would be happy to engage in follow up discussion as required.

High level comments on the intentions of the EN-1, EN-3 and EN-5 documents:

●       The evidence for man-made climate change is unequivocal, driving the need for ambitious reductions in carbon emissions both globally and in the UK.  A secure, reliable and affordable energy system is, however, an essential part of modern life.  Moving towards a low-carbon energy system that meets these needs is therefore essential and, in the absence of any other proven large-scale alternative, renewable electricity generation can be expected to play a major role.

●       Overall, the UK has a strong track record in the development and deployment of renewable technology, particularly offshore wind.

●       Increased renewable supplies are urgently needed if the UK’s 2030/2050 emissions targets are to be met.  Given the delays in the planning and connection process, finding appropriate opportunities to expedite the planning process seems reasonable.  Of course, such efforts should be reasonably balanced with local and environmental considerations.

●       Against this backdrop of a changing physical climate, it is vital to understand how both plant and the overall system will perform in the future climate conditions to which they may be exposed.  Consideration of future climate should not be limited to optimising performance against a narrow range of “most likely” scenarios, and instead take a risk-based approach to understand the consequences of the full spectrum of plausible future climates. 

Suggestions for the committee to consider:

●       The documents presented describe a pathway to enable more rapid development of many areas of energy infrastructure.  It seems appropriate to focus on the projects of greatest overall strategic value as a whole rather than adopting a sequential approach.

●       While the documents in several places recognise the need for new energy infrastructure (e.g, EN-1 §3.3), the challenges of this are somewhat simplified.  In particular, while the statement in EN-1 §2.4.8 that the national system operator (NESO) has “all the tools it needs to operate the electricity system reliably” is perhaps true in the present day, it seems rather complacent given the scale of the system transformation which is occurring and the consequences of possible grid failure (e.g., as perhaps witnessed most recently in the Iberian Peninsula).  The following aspects of this are highlighted:

• As the power system integrates more renewable sources, there will increasingly be extended periods of time with limited generation from synchronous sources (such as gas or nuclear).  Other things being equal, this will be associated with very low system inertia and, consequently, will challenge security via reduced ability to deal with unexpected outages. Technologies exist to provide ‘synthetic inertia’ (including batteries and fly-wheels) through grid forming inverters.  More consideration should be given as to whether the mechanisms to provide this vital grid support are adequate.  This should include assessing the periods and locations where low-inertia events are most likely to occur.
• As noted in the document, renewables are intermittent and highly sensitive to weather and climate conditions.  The implications of this need to be fully assessed on day-to-day timescales to get a better understanding of risk at a “whole system” level rather than for individual components.  This will help to develop robust strategies to ensure security and affordability of the system (e.g., reviewing whether the long-standing “N-1” approach to grid security is still fit for purpose).  There are a wide range of tools from the meteorological science community that can support this.  Specific challenges include:

▪       Low wind, low solar – potentially combined with high demand and low-water availability - both on the GB system and internationally via interconnected regions

▪       High renewables, low demand – associated with low system inertia

▪       Rapid ramping of renewable output

• It is essential that consideration of climatic conditions of the future are considered with any substantial development of both generation and transmission infrastructure, due to changes in availability of renewable resource, i.e. where it is optimal to install these resources due to changing patterns of wind (Abdelaziz et al, 2024, Potisomporn et al, 2022) and future wildfire (grassland and other) prevalence due to increasing heatand drought conditions in the areas where these types of resource are located (Yang et al, 2022).  
• As noted in the “high level comments”, it is important that consideration of future climate seeks to assess the consequences of a wide range of plausible future climates rather than a narrow range of the “most likely” scenarios.  This wider consideration should include, for example, the role of long-term natural climate variations (over decades), the possibility of passing climate system tipping points (e.g. weakening of the circulation in the Atlantic Ocean; Ditlevsen & Ditlevsen 2023), and the side-effects of potential so-called geo-engineering solutions (many proposed solutions seeking to control global temperatures are also likely to have significant impacts on regional climate).
• The role of storage to support the integration of high-levels of renewables – from hours to days to years – needs much more attention at system level.  It is particularly noted that, in addition to low-wind days, significant variations in seasonal, annual and decadal production can be expected and, unless one has sufficient storage to move energy between years, this can be increased exposure to unusual weather years in a renewables/storage dominated system.  Support for very long duration storage (e.g., RSoc, 2023), along with international co-ordination on siting and interconnection (e.g., Wohland et al, 2021) may play a key role in managing this, although renewable production of long term chemical storage vectors such as ammonia may themselves be affected by climate change (e.g. Hatton et al , 2024). Advances in long-range climate forecasting over seasons to years is a separate but important area that has the potential to provide climate services to the energy sector as it continues to become more weather-dependent (e.g., Thornton et al, 2019; Hutchins et al, accepted).
• The growing deployment of privately-owned data centres (e.g., for advanced AI) are also worthy of consideration as part of grid development.  Many of these can be expected to be large-scale, and represent a significant demand load on the power system.  The loss of one of these loads (e.g., if it unexpected switches to its own backup generators) may play a potentially destabilizing role to the future grid network.  Appropriate codes to ensure good ‘grid citizenship’ is essential as ever-larger single loads are connected (i.e., to ensure individual large loads pre-emptively disconnecting from the grid in order to avoid simply avoid risk to themselves and thereby causing wider collapse). Equally, large loads with high built-in redundancy (generators or batteries on site) could play a role in supporting grid stability when called to do so (e.g., Fallon et al, 2023).

Despite the above notes – which do focus on the challenges of renewables as a low carbon source – it is emphasised again that it is vital that the power system continues to decarbonize rapidly.  We therefore believe that it is important to view these challenges as an “engineering” rather than “physically fundamental” issue.  While full 100% renewables may not be feasible in the near term or even desirable in the longer term (due to concerns about intermittency or inertia), this should not be seen as a barrier to making significant progress towards a balanced portfolio of low carbon generation sources to increase resilience.  There is a wealth of tools and knowledge available to understand weather and climate risk to power systems (particularly high-renewable / low-carbon power systems) which can be unlocked to support this goal.

May 2025

References

●       Abdelaziz, S., Sparrow, S. N., Hua, W., & Wallom, D. C. (2024). Assessing long-term future climate change impacts on extreme low wind events for offshore wind turbines in the UK exclusive economic zone. Applied Energy, 354, 122218.

●       Ditlevsen, P., & Ditlevsen, S. (2023). Warning of a forthcoming collapse of the Atlantic meridional overturning circulation. Nature Communications, 14(1), 1-12.

●       Fallon, J., Brayshaw, D., Methven, J., Jensen, K., & Krug, L. (2023). A new framework for using weather‐sensitive surplus power reserves in critical infrastructure. Meteorological Applications, 30(6), e2158.

●       Hatton, L., Bañares-Alcántara, R., Sparrow, S., Lott, F., & Salmon, N. (2024). Assessing the impact of climate change on the cost of production of green ammonia from offshore wind. International Journal of Hydrogen Energy, 49, 635-643.

●       Hutchins, B., Brayshaw, D.J., Shaffrey, L., Thornton, H.C., Smith, D. (accepted).  Decadal prediction for the European energy sector.  For Meteorological Applications.

●       Potisomporn, P., & Vogel, C. R. (2022). Spatial and temporal variability characteristics of offshore wind energy in the United Kingdom. Wind Energy, 25(3), 537-552.

●       RSoc (2023).  Large-scale electricity storage, Royal Society.

●       Santos-Alamillos, F. J., Brayshaw, D. J., Methven, J., Thomaidis, N. S., Ruiz-Arias, J. A., & Pozo-Vázquez, D. (2017). Exploring the meteorological potential for planning a high performance European electricity super-grid: optimal power capacity distribution among countries. Environmental Research Letters, 12(11), 114030.

●       Thornton, H. E., Scaife, A. A., Hoskins, B. J., Brayshaw, D. J., Smith, D. M., Dunstone, N., ... & Bett, P. E. (2019). Skilful seasonal prediction of winter gas demand. Environmental Research Letters, 14(2), 024009.

●       Wohland, J., Brayshaw, D., & Pfenninger, S. (2021). Mitigating a century of European renewable variability with transmission and informed siting. Environmental Research Letters, 16(6), 064026.

●       Yang, W., Sparrow, S. N., Ashtine, M., Wallom, D. C., & Morstyn, T. (2022). Resilient by design: Preventing wildfires and blackouts with microgrids. Applied Energy, 313, 118793.