Heat maps on Germany: renewables and prices
Heat maps on Germany: renewables and prices
A post with colorful charts on renewables and market prices in Germany in 2023
In this post, I will present some heat maps of Germany for the year 2023. Heat maps are an interesting way of presenting visual information, as colors help us to distinguish patterns. There is nothing really new in this post, only another way of looking at data. If you want to dig deeper, you might be interested in these earlier posts where I discuss topics in more depth:
Impact of solar on electricity prices: focus on Germany and Spain.
Some data and thoughts on the complementarity between wind and solar
Do not hesitate to share with me some thoughts on what could be interesting to present in addition to these graphs.
Daily generation of wind and solar
Let’s start with the generation of renewables. Hereunder are the daily generation of solar and wind as well as their combination for Germany in 2023. We can conclude the following from this heatmap:
Solar and wind are complementary to some extent, at least on a daily level.
Week 4 was bad (lowest with 166 GWh/day) as well as week 48 (262 GWh/day) but there were some relatively poor consecutive weeks at the end of the summer as well (weeks 33 to 37 all below average).
The best weeks were in winter (especially 51 and 52), thanks to high wind generation.
Wind generation is lower on Sundays (92% of the average), suggesting economic curtailment or redispatch due to congestion.
Onshore and offshore wind
On the following heat maps, we can see the separation between onshore and offshore wind. Interestingly, the observation of lower wind production on Sundays are only due to onshore wind and not offshore wind.
Prices, solar, and capture prices
Moving on to prices and solar, hereunder is the heat map of the prices per hour and per week1.
We can observe various elements from the above heat map:
Solar is making an impact as we can see the green rectangles during the afternoon in spring and summer.
Prices at the end of winter 2023 were more elevated compared to the winter 2023/2024.
The last weeks of winter exhibit lower prices due to good wind generation and low load.
Some of the highest prices were reached during evening peaks in the weeks at the end of the summer, corresponding to weeks with low renewables generation (as presented in the heat maps on renewables).
The following heat map shows solar generation in Germany with the same granularity (per hour and per week). We can observe the large variations between the winter weeks (with average generation at 1 GW) and spring/summer weeks.
By combining the day-ahead prices and the solar production, we can compute the capture price of solar2. The capture price is the market price weighted by the solar generation. As solar is lowering market prices, the capture price is generally lower as more solar is in the mix.
We can observe that the capture prices are lower in the middle of the day, which could justify to some extent, placing solar on less optimal orientations, such as vertical East-West3. In addition, some hours in spring and summer have extremely low and even negative capture prices (even if each rectangle is an average of one hour over 7 days). Such variation of solar capture price should change our view with regards to renewables support by shifting from maximizing total output to maximizing total value.
France - Germany: difference of day-ahead price
Heat maps can also be used to present the difference between the day-ahead prices between two countries. Here we present the difference between the two largest EU countries: France and Germany. Blue rectangles mean that French day-ahead prices were higher. Two observations can be made:
In the orange rectangle, we see the higher prices in France during the last winter (nuclear availability, poor hydro).
Inside the yellow rectangle, we see lower prices in Germany during the day, suggesting a more pronounced effect of solar in Germany. And, right on the outside of the yellow box, we see higher prices in Germany, suggesting that prices evening prices as well as during the night are higher in Germany.
A last word
I do not have a conclusion except maybe that heat maps are a great tool to visualize data. I hope that some people could get inspired by this work.
If you have any comments, recommendations or ideas concerning these heat maps, please let me know.
Thanks for reading.
Week 53 has not been displayed as it contains only one day. Each rectangle represents one hour of one week, i.e. the average of 7 hours from Monday to Sunday.
Of course, this is not the case as long as remuneration is not aligned with market prices, as is generally the case in many instances.