Watching and learning: how the UK is teaching others how to upgrade the grid

• 4 months ago (2024-07-18)
• Junior Isles

Renewables 776 Solar 272 Storage 45 Wind 256

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Steven Hardman , CEO, Conrad Energy

Across the globe, investment in renewable energy is soaring as countries bid to decarbonise power networks and meet net-zero targets. The strategy deployed to decarbonise will depend on the country’s unique characteristics, preferences and circumstances, with governments potentially looking to decarbonise through solar, wind, or hydropower solutions, or as is most often the case, a mix of these renewable energy solutions.

However, when it comes to wind and solar generated power, there is a common challenge: intermittency. In short, if the sun isn’t shining or the wind blowing, these sources don’t generate enough energy. As a result, countries with a high penetration of wind or solar assets may struggle to plan ahead to ensure supply meets demand. For instance, it is hard to precisely predict wind speeds even just a few days in advance. Forecasting a month ahead with the required accuracy is practically impossible.

The UK is amongst the countries to have invested most heavily in both off-shore and on-shore wind. Indeed, on an especially windy early morning in November 2023, wind constituted 69% of the UK’s energy mix. That reflects the positive steps the UK is making towards decarbonising the grid, but it is also fundamentally unsustainable unless the progress in bringing renewable sources online is matched by progress in managing their variable output.

A new way of managing the grid?

In the past, energy suppliers were able to forecast demand and then accurately plan several months in advance to produce the right energy supply to match. For instance, energy suppliers and the grid operator have historically planned in advance for half-time in the FA Cup final when millions of households were likely to get up and put the kettle on – dramatically increasing demand for energy.

Far-sighted planning of this nature isn’t likely to be possible if the grid is powered entirely by renewable sources, at least with the current technological constraints. This creates the risk that, should the wind die down suddenly, the resulting changes in frequency could cause the grid to become unbalanced, risking damage to infrastructure and even blackouts.

This may at first glance make the outlook for the UK’s energy transition appear gloomy. However, the challenge posed by intermittency can be managed and the result of the UK’s heavy investment in wind power has been matched by efforts to upgrade its power network, adopting an innovative approach to supplementary infrastructure and other solutions to mitigate the risks of intermittency.

One of the key elements of maintaining a balanced grid is inertia, which essentially acts as an equal and opposite reaction to a sudden drop in frequency on the grid, such as one that may be caused by a sudden drop in the wind. Traditional energy generation creates inertia as a byproduct of generating power, so if a power source experiences a fault, there would be enough inertia on the grid to absorb the sudden impact of the fault.

The same is not true of renewable energy sources, and so the UK has by necessity developed technologies and infrastructure to recreate inertia and ensure that circuit breaker protections are connected. This chiefly takes the form of synchronous condensers, the building of which has formed part of the government’s Pathfinder tenders in recent years. But batteries also play an important role due to their almost instantaneous response times.

Embedding flexibility

The UK has also invested in flexible energy solutions that can ensure energy supply remains undisrupted. Central to this has been reform of how the energy market itself is managed, in particular through the introduction of the Capacity Market, which provides for a guaranteed revenue payment in return for a requirement to deliver energy at times of system stress. This gives suppliers scope for ongoing investment whilst providing the grid with a failsafe if needed.

We’ve also seen a growth in the importance of flexible generation assets, such as smaller gas engines and batteries. These can quickly switch on to make up the shortfall in energy supply when required.

Ongoing technological advancements have also helped the UK market adapt including new software solutions to ensure that a diverse range of energy assets are run with maximum efficiency both from a cost and carbon perspective.

How the UK is leading the way

Overall, the effect of these developments is that the UK is able to continue to connect more and more renewable energy to the grid, whilst being more confident that intermittency will not hamstring the transition or cause instability in the UK’s power networks.

Of course, as renewable technologies continue to develop and the share of clean energy on the grid grows, so too does the challenge posed by intermittency. That’s why technology and infrastructure need to continue to develop alongside the transition. In some ways, we are learning as we go as the energy sector landscape evolves. Nonetheless, the UK’s efforts to decarbonise the grid whilst maintaining supply and grid stability, for instance by embedding flexibility and investing in new software solutions to boost efficiency, has seen the UK carve out a position as a world leader on grid management.

Indeed, a number of other countries around the world are watching and learning from the UK on how to upgrade their own grids to accommodate more renewable energy, whilst minimising the risk of blackouts as far as possible. The result of these efforts is that the UK is now well-placed to capitalise on its heavy investment in wind and solar power, whilst providing a route to navigating the intermittency challenge for others to follow.