Feasibility of Germany’s newly proposed RES targets
Background and overview
Meeting the climate targets under Paris Agreement (i.e. limiting the temperature increase to 1.5-2°C) requires rapid and massive development of low-carbon technologies to decarbonise the energy system, where wind and solar power in particular will play a significant role. POLET’s recent research, however, finds that these technologies are not growing fast enough to meet the climate targets, partly because the growth in the early adopters including Germany has stopped accelerating or in some cases slowed down. It is thus timely that the newly formed government of Germany, a global leader in both technologies, now aims to strengthen their renewable targets and re-accelerate the growth, particularly onshore-wind and solar. In this post, I analyse how challenging these newly proposed targets are, what would be necessary to achieve them, and what has been proposed by the government so far.
I find that following the long-term trend of the country in developing onshore wind and solar would result in missing both targets in 2030 (particularly solar by a big margin). However, achieving the new onshore wind target would be within reach if Germany restores its maximum growth speed achieved in 2014-2017 and sustains such speed for about three times longer than the historical max duration. In history, only Spain achieved such speed and duration. Achieving the new solar target, on the other hand, would require establishing new and stronger growth mechanisms for which there is no room for delay to implement, as no country has ever achieved such speed even for a short period of time.
Germany’s current and new solar and wind targets
In 2021, Germany had about 64 GW of wind power (56 GW onshore) and 58 GW of solar power installed. The current renewable targets of the country, set in EEG2021, are to have 91 GW of wind (71 GW onshore) and 100 GW of solar by 2030 to supply more than 65% of electricity (total demand 658 TWh) from renewable sources. The newly formed government is planning to increase these targets to 124 GW of wind (94 GW onshore) and 200 GW solar to supply 80% of electricity (total demand 725 TWh) in 2030, according to the coalition agreement (in German) as well as EWi’s analysis (also in German).
How challenging are these targets?
I answer this question in two steps. I focus on onshore wind because it plays a major role while its growth has recently slowed down thus re-accelerating the growth is particularly important.
First, I use the method developed in POLET’s recent research to estimate the maximum growth rate “G” (for Growth) of these technologies in Germany, which takes into account their projected future growth based on the long-term historical trend by using two S-curve models:
Logistic, which is symmetrical around the inflection point meaning that it takes the same time to grow from 10% to 50% as from 50% to 90% of the eventual market size.
Gompertz, which is a long-tail model, where growth continues for longer after the inflection point.
(On POLET Resources page we have the code for model fitting as well as model curves not only for Germany but for 59 other countries as well!)
Secondly, I analyse whether the growth rates required by the proposed targets have been achieved for a shorter period of time (3 years), and whether such rates have been sustained for more relevant duration as 10 years in Germany or any other comparable country. In order to compare capacity growth across countries, the data is converted to MW and normalised to the size of the electricity system (i.e. MW/TWh). I also omit countries whose electricity demand is less than 10% of Germany (approx. 60 TWh).
Onshore wind
As left figure shows, the two models estimate the maximum growth rates of onshore wind in Germany at 2.7-3 GW per year, with inflection points located in the mid-2010s, which means that the models detect a gradual slow-down of capacity additions in the recent years. While Germany would be able to meet the current target by following the Gompertz (long-tail) curve, it will miss the newly proposed target even if these rates at the inflection points are immediately restored and sustained over the coming years (dashed “what if” lines).
Instead, meeting the new target requires Germany to re-accelerate to the speed of capacity addition in the fastest 3-year period between 2014-2017 (about 4 GW/year, see the left table*) and sustain this growth for a decade.
*For the historical periods in the table, 3 year moving average data is used to better reflect trend of growth and to be compatible with the below country comparison analysis.
Has any country achieved such speed and sustained it for a decade? Fortunately, the answer is yes.
The above figure shows top 10 countries with highest growth speed in history, where the left panel shows the historical max annual growth of onshore wind in 3 years moving average, and the right panel in 10 years moving average. As mentioned, Germany for a short period of time achieved the speed necessary to meet the newly proposed target (in 2014-2017, Germany added about 4 GW/year, which is 4000MW, divided by the system size/approx. 640 TWh at that time = 6.3 MW/TWh as shown in the left panel). However, this speed did not last as long as 10 years (right panel) which is exactly what is necessary in the future. Only Spain and Romania in the world achieved higher rates than Germany, in which Spain sustained such high speed over a decade. This means that Germany could achieve its new target if it develops onshore wind as fast as Spain did in 2000-2010.
Realising it may nonetheless be challenging as it requires, according to the coalition agreement, securing 2% of the land area for onshore wind installations and significantly shortening the approval process by prioritising wind over other interests such as natural conservation. Even more radical measures such as designating wind power construction a matter of public security and expropriating land for wind development were proposed by wind industry groups, according to Clean Energy Wire.
Solar
The two models estimate the maximum growth rates of solar in Germany at 5.3-5.7 GW per year, with inflection points located in the early 2010s (left figure). While the models detect a rapid slow-down of capacity additions after these points, solar started to grow again in the recent years though at a slightly slower rate than in the early 2010s. Restoring this max speed and sustaining it until 2030 (dashed “what if” lines) would be enough to achieve the current target (100GW), while the newly proposed target would still be missed by a big margin.
Instead, meeting this new target would require adding about 15GW/year between 2020 and 2030, a very rapid speed which has never been achieved in Germany (See the left table*).
*For the historical periods in the table, 3 year moving average data is used to better reflect trend of growth and to be compatible with the below country comparison analysis.
Has such speed ever been achieved in other comparable countries? Unfortunately, the answer is no.
Once again, I normalised the data here to compare Germany with other countries (e.g. in 2009-2012, Germany added 6.9 GW/year of solar. This is 6900 MW, divided by the system size/620 TWh at that time =11.1 MW/TWh as shown in the left panel). I do not find any country that has achieved the growth speed necessary for Germany’s newly proposed target (200GW) in 2030. So far, no country achieved even the rate required for the previous target over 10 years, let alone the rate for the new target (right panel). This indicates that achieving such speed (i.e. quadrupling the maximum growth level observed in Germany over 10 years in 2009-2019) requires new and stronger growth mechanisms rather than incremental improvements (such as shortening the project approval process in the case of on-shore wind) in existing ones.
We are yet to see whether and when the planned federal mandate of installing solar on a large part of buildings can be implemented in Germany and whether it would be enough to achieve the new, significantly more ambitious target. Needless to say, should there be any delay in establishing such mechanisms (technically, we are already in delay), achieving the target would become even more challenging.
Conclusion
Mitigating climate change requires ambitious and often unprecedented level of efforts. POLET research group contributes to realising such efforts by analysing the conditions and capacities necessary for them.
This post analysed the feasibility of Germany achieving its newly proposed renewable targets and identified what has been proposed to achieve them. I find that following the long-term trend of the country in developing onshore wind and solar would result in missing both targets in 2030 (particularly solar by a big margin). However, achieving the new onshore wind target would be within reach if Germany restores its maximum growth speed achieved in 2014-2017 and sustains such speed for about three times longer than the historical max duration. In history, only Spain achieved such speed and duration in 2000-2010. Achieving the new solar target, on the other hand, would require establishing new and stronger growth mechanisms and there is no room for delay in implementation, as no country has ever achieved such speed even for a short period of time.
As a front runner in ratcheting up climate policies in particular regards to accelerating the growth of renewable technologies, Germany will continue offering great insights into whether and how much the historical frontier in the speed of developing renewables can be pushed forward.
