Feeling the heat: Preparing Europe's grids for summer

Hello listeners, and welcome to Plugged In - the Energy News podcast from Montel, where we bring the latest news issues and changes happening in the energy sector. It's only early June, yet Europe is once again sweltering under extreme temperatures from record breaking heat waves to growing concerns about grid reliability. The pressure on Europe's electricity systems is becoming impossible to ignore as transmission networks operate closer to their limits and the energy transition accelerates our Europe's power systems prepared for a future where extreme weather becomes the norm rather than the, except.

Last year's blackout across the Iberian Peninsula brought energy security and system resilience sharply into focus. There is growing debate about grid investment, flexibility, reliability, and whether Europe's infrastructure is keeping pace with a rapid transformation of its power sector. So what happens to an electricity system when temperatures soar? Are grids becoming the weakest link in the energy transition?

And what investments are needed to ensure Europe can keep the lights on in a hotter and more electrified future setting? The scene for us today is Julia Demirdag , our Germany correspondent based in Frankfurt. A warm welcome to you, Julia. Hello.

So Julia Europe has experienced several major heat waves in recent years. Are electricity systems now facing a fundamentally different operating environment than they were a decade ago? Yes. Definitely I would say.

So a decade ago running a grid was a relatively predictable business, and today it's a more like a high stakes balancing act, basically. 'cause we have several factors that have changed over the past years. One is obviously the build out of renewable power, especially solar, which in the summer is flooding the grids during midday and then is flooding out of the grids in the evenings. So we now see maybe during one hour we see 10 gigawatts of a power drop in power generation, which 10 years ago would've been maybe equivalent to 10 nuclear plants leaving the grid within one hour, which would've been unimaginable almost.

And so that's obviously a big difference. If you look 10 years ago we've seen a lot more arctic ice, and this obviously now is melting with climate change. So we are currently near a record low, and the arctic ice is something that has provided cooling for Europe, but right now Europe is the continent that heats up fastest with climate change. So we see more heat waves, they're more pronounced and they last longer.

So yeah, we see just more heat than a decade ago. And yeah, also drier weather. Yep. And that's obviously I increases the demand for air conditioning in certain markets.

But when people think about extreme weather and energy, they often focus on a power production or generation Julia but why are grids and transmission networks increasingly becoming the critical point of vulnerability? Yes, I would say the main point is that the wind and solar power has been expanding massively over the past year, and that's something, a solar plant is something that can be built really fast. So say, I don't know, a few months maybe while a grid takes decades to build and to build out.

So they're just not keeping pace with the expansion of renewables. So it's like we've built all the cars, but we forgot to build the highways that they can use. Yeah. Julia, thank you very much.

You are welcome. Thank you. As renewable generation expands and extreme weather becomes more frequent, keeping the grid stable is becoming just as important as generating enough electricity. So what does that mean in practise?

I'm joined by Guy Nicholson, head of zero Carbon Grid Solutions at Statkraft. Guy, a warm welcome to plugged In Podcast.. Thanks, Richard. Great to be here.

Great to have you on board. I think we're here to talk about heat waves, blackouts and grid resilience. Now they're often discussed as a challenge for grid operators, but from your perspective, how do periods of extreme heat affect the wider electricity system and marketing more in general? Yeah, so I think it probably comes down to the laws of physics.

You know, heat creates warmer temperatures, things have greater resistance at higher temperatures. And with the old Ohm's law, we got more resistance means more heat. So you can get into a vicious circle. So how does that play out really in terms of practicalities?

It means that terms of high temperatures, you're gonna have more forced outages of plants and therefore grid operators would probably, move away from, move to a more secure system, perhaps restrict outages that might be needed to connect a new generation and new projects, new data centres, grid reinforcements and all that. So it restricts the landscape, if you like for new connections and grid developments by having to effectively operate the grid to be resilient to these forced outages of plant in these high temperature conditions.

So it's a kind of double whammy on top of what we're trying to do. Just makes what we're trying to do even harder. Yeah. And get to net zero.

Absolutely. So what kind of infrastructure is largely affected by this extreme heat? I mean, you met obviously grids, but what kind of power plants and what kind of production or generation units? Yeah, so I guess if you go to the power plant side, then you know, you've got things like, remembering the, you last heat wave in France where lots of the nuclear were switched off because the cooling water's too hot.

They're having to break environmental laws to discharge hot cooling water into rivers and lakes, with impacts on wildlife. And eventually turn plants off. So then that restricts the amount of plant available, and again, that creates additional, stresses on the system. And then fossil plants as well, higher temperatures become less efficient to the thermodynamics.

So it's it compounding the challenge of high temperatures. I think, the other thing people will say is yeah, solar is less efficient at high temperatures as well, but then we have more solar available, so that's counted to a degree. And obviously air conditioning demand is going up with higher temperatures, but we've also got more solar and particularly more embedded solar and distributed solar, that, that helps to counter that and reduce the load on grid. The renewables are definitely helping resolve this situation in many ways.

And that solar air conditioning, cooling match is very helpful in that regard. But what about wind, for example, when there's a lot of times of extreme heat is often not very windy. I mean that, that's a sense. Anyway, it's all quite sticky or muggy or very dry and hot.

I know that the Germans have introduced this word into the English language called Dunkelflaute. Yeah. But also you have this thing called Hitzeflaute as well. So when, when there's very little wind, when it's very hot, is that a fair new addition to the English language Guy?

I'll take it away. And thanks for introducing me to Hitzeflaute. Richard obviously Dunkelflaute, as you say, is well embedded now and, a useful term. But I think at the end of the day the point of renewables is to displace fossil fuels from the day-to-day generation mix.

It's not necessarily to get all fossil fuel plants shut down we will still need fossil fuel plants, therefore the Dunkelflaute, so they can still operate in the Hitzeflaute, if I got that right. Probably didn't. But yeah. The fossil fuel plant is there just means we have to run it more, which is not a good thing.

But yeah, the mission for renewables is actually getting fossils off the grid most of the time. Yeah. Getting to the zero carbon operation of the grid. And if we have to run fossil fuels occasionally when there's a Dunkelflaute or otherwise, that's not big issue.

The big issue is getting the fossils off the grid by having lots of renewables there and a, a good stable grid to run with those renewables to allow them to operate. And that's, I think should be the key focus at the moment. For sure. You mentioned cooling demand and that's growing the demand for air conditioning as these, as we enter these various sort of periods of extreme weather or extreme heat.

Are we seeing a fundamental shift in, in electricity consumption patterns? And what does that then mean for system planning? Yeah. If I go back to working on first wind projects in South Australia, in around 2000 and South Australia, the end of the nineties was transitioning from winter dominated peak demand to a summer dominated peak demand.

And that happened very quickly as people got air conditioning and so on, driven by the availability and climate change. And we're gonna see that happen more widely. But again, with solar matching very well with that, I don't see that as any big issue. I think, we have seen demand flatten and even fall in, mature grids in, in Europe and the US Yeah.

And that has been down to a lot down to energy efficiency, things like LED light bulbs. We used to use 10% of our GB electricity on lighting, and that's just smashed to bits by led. So the whole efficiency process has helped reduce demand and now we are gonna see demand go up as we get electrification of vehicles, electrification of heat. That dip in electric consumption is starting to reverse.

Plus, yeah, all the talk about AI data centres as well, so drive, driving up demand. So we're seeing a rise in demand from now on is how I look at it. I mean if we go back to these kind of periods of extreme heat as well, I think they used to happen every three years or remember going back I've been in this market a well, so not quite 2000, but 2003, 2006 were key area then also a few years ago. But it seems to be happening every year now or certainly on an annual basis, but also earlier in the year.

So we've had this extreme, this period now in May rather than in July and August. Is this, are there different patterns emerging here? Guy? I dunno if you've modelled this or looked at this in any way.

Not my fault, I have to say in terms of, what is the trend in this area? So as someone else on that, I think my focus is really on how we deal with it wherever it happens, whenever it happens and there's always something different and new happening with demand, with generation, with the weather, whatever it is, with cybersecurity, there's always changes, there's always threats, there's always new challenges. And I think my focus really is how do we build, operate, and run a grid that is resilient to whatever gets thrown at it from all these different aspects rather than focusing on is one pattern Absolutely fair.

Fair enough. I just jumped into my mind for whatever reason. But I, if we look at, system resiliency and that, I think flexibility is often described as one of the key tools for managing, electricity system stress. How can batteries, demand response and other flexible resources help maintain that reliability and that resilience during these periods of extreme weather?

Yeah, so I think there's that, what I might call adequacy of the system. Do we have enough generation to meet demand? Do we have enough network to get the generation to where it's needed? And I note that Entso-E have called out a couple of island systems in, in Europe in their summer outlook if you to say resilience adequacy issues and where you've got a, an island with limited interconnection like the island of Ireland.

If you have a lot of outages of plants, if you have high demand 'cause of. Air conditioning load. I don't think it's quite got there in Ireland yet, but it will do then, do you have enough plant interconnectors and so on to, to deliver that? And things like batteries come in enormously to that providing that, that lump of energy.

And we've seen, the battery durations that we deal with when we put our first battery systems in, 10 years ago, we're talking about a half hour battery, and it was focused entirely on frequency response. And we've now seen in our recent batteries, four hours duration, we're looking at long duration energy storage with eight hours and more duration. So that, lowering cost of batteries has enabled us to put in larger and larger duration systems. They can have a massive impact, not just on a sort of an event where there's a sudden loss of demand, a loss of an interconnector, a trip of a big power station, and batteries can easily jump in and fill the gap, but also with the evening peaks and so on.

Or even a longer period of high demand or, yeah, a loss of particular generation sources for particular times or, the reduction in efficiency of fossil plant during hot weather, for example. That storage is transformational, making a massive impact on grids worldwide. Some ahead of others, obviously, but everybody's moving in the same direction on this stuff. I think the other thing is, with.

What I call stability. And if you're like what happened in Spain? We had an in stable grid with, from a voltage instability point of view in Spain, then, that's the kind of lack of ability to manage voltage. We can have similar things with inertia and so on.

So having equipment in the grid to provide services to manage these new challenges, that it's really a great opportunity. The technology's there, it's just about deploying it and getting it in place and, stack we're putting in batteries for which, which provide things like frequency response, moving into things like inertial response from batteries. We've already got synchronous compensators, which provide excellent voltage stability, inertia, system strength, f current, things like that.

So all these services that have to traditionally been supplied by fossil fuel generators, when those fossil fuel generators aren't on the grid, they can't supply the services or so, so we can provide those services with these new technologies or new embodiments, if you like of existing technologies or new refinements that enable us to run a grid with a hundred percent renewables without any fossil fuels running. So that's the, that's once we can do that, we can be also resilient to a lot of stuff that the weather can throw out as, or cybersecurity can throw out as or whatever.

So you mentioned eight-hour batteries or even larger ones, are they already commercially viable 'cause, I would say not generally commercially viable in, in the markets I'm in. There may be some markets where they're, but it's coming. And in, in UK we've got the long duration energy storage scheme, a cap and floor scheme to support that kind of duration. We batteries or pump storage as well.

New pump storage projects as well. So envisaging that world where we, need more of that longer term storage to help us out with the surplus renewables that we're gonna have on the grid. And rather than throw it away, can we put it into storage and then use it later in, in when it's needed? Absolutely.

These are valuable electrons and generated or green electrons even. So we don't want to waste them. That's very important. But Guy, where do you think the biggest gaps remain when it comes to building a more resilient power system?

Yes, I think it's about speed of delivering these, grid services, ancillary services, system services. People call them different things. We, which don't need the, therefore we don't need gas or coal or whatever to deliver them. And if we go back to COVID, then in, in GB, like call, one afternoon in, in, in spring where we had lots of wind, lots of solar, very low demand, 'cause COVID shut down and the market said, we don't wanna run any fossil fuels.

And the system operator said, hang on a minute guys, let's just stop there. We can't run the system stably without all these fossil generators. Not 'cause of the energy, but 'cause of the voltage control, 'cause of the frequency control, 'cause of the inertia, 'cause of the fault current or short circuit current. And so they switched off a load of renewables and turned on 17 Gasified power stations.

So we were in a position to run a zero carbon grid, but we couldn't do it because of the ancillary services, the system services. And we still, NESO, the GB system operate has this target to operate a zero carbon grid for the first, half hour or hour. Still hasn't quite got there because we're too slow in delivering these new services and these new technologies. And part of that challenge of that is actually just getting access to the grid.

So the grid is so congested in terms of outage planning. We need to take, switch things off to connect new stuff up to reinforce the grid. We wanna keep an intact grid to maximise the flows of renewables and so on that we've got, so all these tensions work out that it just become challenging to actually connect new stuff to, to en enable these zero carbon operation to happen. But yeah, we've got very close this year.

We haven't quite got there yet, but I'm sure we will. And then from, the initial hour, which you've cracked that you just do more of the same. So it's getting that first hour of zero carbon operation on the grid and a very much happened with coal. You've got a first coal free hour, the coal free afternoon, coal free day, coal free weekend.

And it'll just grow and grow like that so that we can operate our grids without any fossil fuels for, 90% of the time. That's the ambition. Anyway, that's gonna be the, that's the sort of one hour sweet spot. Once you hit that, then, oh, big celebration.

Yeah. I'll be getting there. The beers out. Yeah.

For that. Yeah, that'd be great. Fantastic Guy. Thank you very much for being a guest on the Plugged In podcast.

Thanks Richard. It's been a pleasure. While technologies such as batteries and flexibility services are helping to make power systems more resilient, the bigger question is whether Europe's grids and policies are keeping pace with the challenges ahead. To explore that, I'm joined by Paweł Czyżak Europe Programme Director at Ember.

Great to have you on the show again, Pavel. Hi Richard. Looking across Europe, how vulnerable are electricity systems becoming to increasingly frequent and intense heat waves? It's becoming more and more vulnerable because they do happen more often and they are also happening earlier in the year, so we just had a heat wave, a week, two weeks ago.

That was a bit unexpected because it was still may so it used to be more in the summer months and it's definitely a theme over the summer and it's definitely repeating itself in terms of the impact on the power system. So increasing prices, problems with balancing, problems with cooling, the thermal plants. It's a thing that will keep happening every year basically from now on. Do you, I mean you are based in Poland, Pawel and Poland is quite reliant on fossil fuels, especially cold.

How was, in terms of the waterways, the rivers in Poland, how are they being heat impacted by these kind of heat waves and for example, the Vistula a few, we, a few months, a few years ago, levels dropped very low, right? Yes. Poland like a few other countries, has this problem of heat cooling the thermal plants with water. If the water is too hot in the river, it basically, it can't be used for cooling the thermal plants, so they have to ramp down.

And that keeps happening in, in Poland and France and Germany. And it happens to nuclear plants, to coal plants mostly. There are some remedies, but that's one thing. The other problem is just drought, so that on the other side of the spectrum, we have the hydro fleet still a big part of Europe's power system, and we consistently see low production from hydro power plants due to droughts pretty much every year as well.

Absolutely. And I think, sometimes when we talk about blackouts or system stress, specifically for grids and transmission and distribution networks, renew energy seems to take some of the blame. Do, is that a fair assessment or does it overlook deeper issues within the power system across Europe? I don't think that's a fair assessment.

And in fact in the last heat wave last year, it was mostly solar energy that saved us from trouble because the nuclear fleet in France had to ramp down so much that it was pretty much only solar, that kept producing power during the hot days. So I wouldn't say that they are to blame. There's many things in the European power sector that just, or system that just are quite old. So the grids are quite old.

The centralised power plants, even the, we keep mentioning the French nuclear fleet, that's 40 years old, right? So a lot of that equipment just is ageing and that means also the grid infrastructure, so the lines, the substations, the transformers. And that also means that they are impacted by the heat. So if you have very high temperatures, the basically the lines can carry that much power and they're more, more prone to failure and they are, they just have lower.

Say you can only flow less power through them. So a solar system becomes more congested and generally more stressed. So it's not so much, if I understand you corrected Pawel, that it's not so much that solar and essentially wind their input or their feed into the grid is a problem. It's also the grid itself that's not actually fit for purpose in the sort of modern 21st century power system.

Would that be a way of looking at it? Yes. There, there are challenges of course, in balancing and integrating wind and solar into the grid, so that, that's why we need more storage, for example. And then that's why we keep building more storage.

But what I'm also saying is that just the grid is old. Wow. So regardless of the power mix and the generation side, we have these, 40, 50 year components that, that are just ageing. I think I, I recently read about transformers in the uk.

I think the average age is like 57 years old or something like that. So that's just a system that was built in a previous era. That ageing infrastructure built for Exactly. These sort of very, this very centralised power system with big blocks of generation.

Absolutely. But what do you think the Iberian blackouts revealed about European electricity networks and you think, are there lessons that apply beyond Portugal and Spain, Pawel Definitely one lesson is that if you lack interconnection, it's much more difficult to handle any types of disruptions or disturbances, even. So the Iberian blackouts, a lot of it is because the peninsula is separated from the rest of the power market in Europe because there's just not enough interconnection capacity with the neighbours.

So normally if you had a similar situation like that in say, Germany, a disturbance in frequency may be a few power plants coming offline. That would all be buffered by the wider system. So you would have some more imports from France, more imports from Poland, from Denmark, and it would all level out in Spain and Portugal, it's different because they don't have that much connection with the neighbours for those buffers. So I think lesson one is you need the interconnection.

And then lesson two is there were a few maybe inefficient solutions in terms of market design and power balancing that are actually being fixed and were addressed very quickly by the government. So they came up with the whole package of solutions, incentivizing storage, for example, or unlocking the participation of renewables in voltage controlled. That was one of the issues there as well. So I think the Spanish government is doing quite a lot to learn from that and apply the lessons very quickly.

And these of course apply to other countries as well. This isn't something that is only possible in Spain. It might as well happen in, any other European country. And I think that's very clear, the lessons learned, inertia, frequency and voltage control are absolutely key issues here, aren't they, in terms of keeping that system security.

But you don't see the same kind of issues that affected the Iberian Peninsula or the blackout that originate in Spain as far as we know affecting other parts of Europe. Certainly like in your part of the world or Central West Europe, central East Europe. I would say there's a lot of change happening in the European power system that is very interesting to watch and that might result in maybe trouble at some point. And that mean what?

What I mean by that is, for example, in France, again just last week, very high solar curtailment that is quite, happens quite quickly. Then the very inflexible and old fleet of nuclear plants that always has trouble during heat waves goes offline, has a lot of outages. So a com combination of those dynamics without the storage that we need. That's potentially trouble.

Then we have the second big risk that is maybe a bit not prominent enough sometimes in analysis is outside sabotage or interventions or disruptions. The types of situations that we saw in Estonia, for example, in Moldova where the link between Finland and Estonia got disrupted by a shadow fleet vessel. And, that cut off basically around half of Estonia's power demand in an instant. Those types of situations, or sabotages in Berlin twice recently.

That type of thing, cyber attacks, those types of things are very difficult to predict. But they keep happening and I would assume they will keep happening. And we need also mechanisms to protect our against those types of threats. What kind of mechanisms are you thinking here, Pawel?

I would split them into two. So one is the, or maybe more, but one is the, say prevention. And for example, I will mention storage. Again, if you have more storage, then you can buffer a bit more.

So you can, if it's if someone takes a power plant off flying, then you have this buffer of power stored in batteries or pump storage plant or even demand response units. That helps you survive the disruption in the short term. Then you have maybe grid resilience, grid protection, so all of the stuff that just makes attacks more difficult. That's can be maybe monitoring or CCTVs in substations or it can be Denmark is, for example, testing drone ships that would, monitor the subsea infrastructure, subsea cables, all of that.

And then you have the recovery. I think that's again, something that's missed often, but in Spain we saw that the recovery of the system was actually quite difficult. And once it's down. You need specific types of power plants to basically put it back up.

And those were hydro plants and interconnectors in the case of Spain. So power from France and Morocco plus a few hydro plants. But if some of them failed actually so restoring such a system is not that easy. And you can again, do it with different measures, but we're not very well prepared to actually do that because it doesn't happen often.

There's pilots projects, there's projects that would use, again, grid forming inverters, solar with batteries to try to do that. You have options like gas and hydro, you have the interconnectors, but we don't test often for that, and we don't really, we not done it often, really in history. So those types of scenarios I think we need to plan for and we need to prepare for. I think those are very important points.

I think the recovery and the prevention are two, two very diff very important factors. Pawel, what I'm also interested in a little bit is, you often you get, the focus on renewal intermittency, and that is very hard for backup once the system goes down or whatever. But it's not quite that straightforward with gas fired plants either, is it? They don't they, it's not just plug and play.

Sometimes they will start up and fail, start up, fail again. Hydro is more stable in that sense, is it not? Yes, definitely. That's, again even in Spain, we saw exactly that.

They do have some gas plants, but the whole system was restarted with hydro units I think around seven of them. And quite a few of these energy islands or power islands how you call them they just failed. So the frequency because they start up a generator, then you start connecting loads and then it might turn out that the generator can keep up and it just goes down again. Yeah, it's a tricky process and the more redundancy you have, of course the safer you can be.

Absolutely. A final question for you, Pawel. So as Europe continues to electrify and decarbonize, you can argue whether it's going too slowly or too quickly, but what should policy makers prioritise to ensure the power system remains both clean and resilient? That's a tricky question 'cause it's definitely not one thing.

But I would double down on storage at the moment because we've managed to deploy quite a lot of solar especially, and there's a long pipeline of project in storage in a few countries. But they need to be built, they need to be connected, they need to be, go through permitting quickly. So I would absolutely focus on that because there's two benefits or maybe more actually, but you improve the balancing situation, you improve the grid resilience, the recovery as well. And then you also improve the business case for solar even more.

The more storage you have, the, the flat, the prices are smoother or there's less negative price hours and all of that. So that just boosts solar deployment as well. So that would be my top one priority. And then you have a long list of course, market measures, grid measures, flexibility measures as well that need to go together with of course renewables and the storage.

But I think for now we're definitely lagging behind on, on batteries. So that's what I would focus on. Yep. That's a very important point.

But I think, but isn't it also the fact that with batteries, it's not just the magic bullets. I mean you need to locate them in the right place, you need to have them starting up, but that at the right moment, it's not just a battery is the answer to all of our problems with the electricity system, eh? Or is it, I dunno. Of course.

I think the biggest point is maybe the, what you mentioned about managing them. So that's still not fully maybe regulated and handled in all countries. So a lot of the storage comes as even household plugin units and they don't necessarily talk to the grid operators, right? They're they dumb units, they just store and discharge.

But what you really need is some type of control over that. So you can manage it. The same actually with solar. So that's work in progress and in, in quite a few countries still.

But in a way they're quite simple devices, so I don't think, it's a matter of standards, maybe of software systems, but it's not rocket science. Definitely. So it's much easier than building a grid, let's be honest. So I think for now, measures like that, plus measures on the demand side octopus energy in the uk schemes where people just shift their demand a little bit within the day, that, that makes a big difference for the grid as if it's a million people or 5 million people, stopping their kettles.

That's quite a few gigawatts that we can shed off the load in stress moments. So solutions like that are pretty simple. They just require maybe a bit of coordination, a bit of regulation, but it's not technically complicated. That, that's exactly where guys like you come in, Pawel, is to make the system more intelligent, more smarter, to move away the dumb kind of systems that we don't really want or are not gonna be that helpful going forward.

But thank you very much Pawel, for being a guest on the Plugged In podcast. Thanks so much. And to you listeners, thanks for listening to this episode of Plugged In. If you enjoyed this discussion, please like rates and follow to make sure you get the latest podcast episodes as soon as we release them every Thursday.

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