Grid reliability: Is nuclear the stabiliser we’ve been looking for?

Grid stability is consistently brought up as a key puzzle that needs to be solved to reach our net zero targets. One often overlooked piece, states Bernard Salha, group technical director and R&D director for French energy giant EDF, might be found in nuclear power.

Although the volume of renewable energy sources coming online is an accolade worth touting, the issue behind intermittency persists.

However, an answer might just be found in the role of nuclear and Salha, in an Energy Transitions Podcast episode, stated his confidence in this being the case:

“Nuclear is clearly an asset to cope with the question of overall intermittency and, let me also say, the question of global stability of the grid.

“The big question with renewables is that you have electricity (only) when you have wind or when you have sun…”

The go-to answer for this intermittency conundrum is the use of storage systems, whether battery or long-duration, which can be co-located with renewable power plants to store energy when generated and discharge back to the grid during peak hours of demand.

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However, states Salha, storage technology is not yet at a level where it can be fully relied on to keep our grid in check for the foreseeable future:

“…the development of storage, at least of big (enough) volumes of storage, is not yet here, and is probably not going to be here for a very long time.

“There are technical devices, which allow us to have stability on the grid – grid forming systems for example – but nuclear could help also in that respect by its natural inertia. And nuclear is flexible – that’s a key element I really want to stress; nuclear is flexible.

“On our French fleet, we have reactors, which can increase (…) or decrease power very fast; the technical spec, with grey rods to which the reactors are equipped, is of 3% full power per minute.

“Nuclear power plants can follow the load, and consequently, they can help to bring stability on the grid.”

According to Salha, ensuring the stability of our grid systems needs to be recognised as a crucial element for the success of the energy transition as, with increasing shares of electricity and renewable energy coming online, its functioning will need to be maintained throughout.

“As each share (of energy) is going to be larger and larger; we need a strong grid and a stable grid.

“And in that respect, a nuclear power plant with the flexibility and capacity to follow the load is clearly an asset in this global, complex landscape.”

Smart grids on the case

According to Salha, a way in which the integration of nuclear, as a decentralised flexible load, can be efficiently coordinated is through the use of smart grid technologies.

In fact, it is not a way, but rather the way:

“The question of this very big increase in electricity means that we are going to have a lot of different demands – (from) EV charging stations, heat pumps, industrial customers – and we will have to manage the global stability, the global frequency, of the grid…

“It means that all these global systems have to use digital tools. Digital tools in that respect are mandatory if we want the system to be able to operate. All the AI techniques, all the tools which may help the global operators in charge of the management of the grid to work are going to have a great effect and are completely necessary.

“We have to take into account that this global system is going to be more complex, more decentralised with several actors, and that the stability is going to need to have all these actors, all these different players working together.

“In that respect digital systems for grid management are abgsolutely necessary.”

Make sure to listen to the full interview with Bernard Salha on the Energy Transitions Podcast