Pan-Europe wind & solar = stable output

 A most interesting thread from Sarastro on Bluesky.

The past two days we [have] seen something interesting in the European power market: continent wide balancing that is providing security of supply at the lowest prices driven by commercial incentives…

We know that solar and wind and inverse output characteristics. A system that contains both is more secure than one or other alone. This chart from @ember-energy.org makes the point on a European wide scale

 

You can see that on a European wide scale the combined output of wind and solar is less intermittent than solar and wind alone. These charts do not show the risk of hourly balancing though so you still need a source of flexible generation. [Or storage]

This morning we can see that in action. The French grid is importing power from Spain and exporting it to other markets across the French grid in Northern Europe. That’s how you get solar from southern Europe to Northern Europe and wind from the north to the south

 

But take a look at the output of the French nukes: the French have reduced nuclear output in response: they are not just wheeling power across the French system they are managing the French system for cost and using the nukes as a battery

It’s a revelation for those (like me) who have thought of nuclear has inflexible. EDF is showing us that at the heart of the European grid is a huge battery, its nuclear park, capable of firming both south solar and northern wind.

Yesterday we saw something similar with wind from the uk being imported into France and French exports to other European countries

But critically the nukes modulating output…

A couple of points:

1.  I've talked before about how wind and solar tend to balance each other, not just daily, but also seasonally.  It's not perfect, but on a continent-wide grid (as in Europe) the necessary storage/dispatchable power needed (such as gas) is significantly reduced from what would be needed if just wind or just solar was used.
2. Like Sarastro, I also did not know that nuclear could be ramped up and down.  Notice that the percentage moves are small --- roughly 20% --- but because nuclear is so large in European generation, that's enough to go a long way to balancing total grid output.  From the top chart, I estimate the seasonal variability of wind and solar together as ~10% of total output.
3. New nuclear is still much more expensive than new wind+solar combined with 5 hours of storage.  In Australia (without nuclear), 5 hours of storage with 20% overcapacity of wind and solar is enough to provide a stable grid for 99% of the time.    The tricky period seems to occur in July (mid-winter in Australia), when periods of little wind combine with low insolation and high demand for heating, a situation which is called dunkelflaute.  Even though this is a problem only 1% of the time, it would be unacceptable to close down the grid.
4. The solution, until we get better methods of long-term storage, is gas.  Currently, natural gas, but plausibly, in future, synthetic natural gas via the Sabatier process, produced using surplus green electricity.  
5. Alternatively, concentrated solar power (CSP) may do the trick.  Vast Solar, an Australian company, is busy constructing a CSP plant at Port Augusta in South Australia (on the edge of the desert, with lots of sunshine and heat --- CSP doesn't just use light, as solar panels do, it also uses infra-red, otherwise known as heat.)  CSP provides much more storage than batteries (1 hours compared with 4), so is much cheaper for long duration storage.  (Now called Vast Energy, the 30 MW CSP plant is yet to be started, with start-up now planned for Q2/2025.  However, they will now be co-producing green methanol at the plant as well)