Stumbled upon this tweet of Damien Ernst on solar energy:
The text of the tweet:
The map that shows that if Europe can quit fossil fuels thanks to solar energy, then the US can do it too. #ParisAgreement
That map shows the sunshine hours in Europe compared to the United States and it is clear that the Americans enjoy more sunshine hours than the Europeans. I live in a region with an frisky blue color (1200 – 1600 hours) and, looking at the institute that the twitterer works for, he is living in this region too.
I understand that this statement is conditional. If Europe can quit fossil fuels thanks to solar energy, then according to this map, the US could do it too. Could even do it much easier.
So far so good.
The big question that is burning on my lips: can Europe actually/eventually quit fossil fuels thanks to solar energy?
The first part of the puzzle is how much solar energy is consumed in Europe and the US? There are many sources spreading around graphs and individual numbers. The most detailed data that I found (without having to reach for my wallet) comes from the BP Statistical Review of World Energy 2017 report, with detailed data on primary energy use worldwide. Unfortunately, they only go to the level of “renewables”, so lumping together solar, wind, biofuels and so on.
Luckily, they also have a BP Statistical Review of World Energy 2017 Renewable Energy report, which is the break-down of the numbers in the Statistical Review of World Energy report. This report also has detailed numbers for the renewable fraction from 2006 until 2016.
It is not clear what the twitterer meant by “Europe”. It is most likely that he meant the “European Union”, since the EU is doing the most effort on renewable energy of the countries on that map. So for the calculations ahead, I will take only the countries in the table that are members of the European Union (there are 22 EU member states in that table). This selection is the most favorable for the theory of twitterer. I will also exclude the category “Other countries”, since I don’t know whether these are from “Europe” or “Eurasia”.
According to the renewables report, the US consumes 12.8 million tonnes of oil equivalent (Mtoe) of Solar energy and the 22 EU member states 24.9 Mtoe.
Only 5 countries of those 22 account for most of the solar energy use:
- Germany (8.6 Mtoe)
- Italy (5.2 Mtoe)
- Spain (3.1 Mtoe)
- UK (2.3 Mtoe)
- France (1.9 Mtoe)
That is 85% of the solar energy use among them.
So far so good. Europe certainly has the lead over the US on solar energy. Despite it is receiving less sunshine than the US (it even has 2 of the 5 lead countries in the blue and turquoise regions), it still manages to have a consumption of solar energy of almost double that of the US.
However, when we look at the annual growth rate, then we notice that the US has a growth rate of 43.6%, while Europe/eurasia group only has an average growth rate of 3.6%. When I make the comparsion of the trends from those 22 EU member states and the US, this is the result:
The growth of solar energy in Europe is slowing down while the US is still going strong. This could change with Trump as president, but in the media there were pledges from activists and companies to fill in the gap, so this growth could keep on going for a while (unless those pledges were only virtue signaling of course).
Among the European countries that contribute to the slowing down of the growth rate, there were even 3 from those 5 lead countries: Germany (a “growth” of -1.6%), but also Italy (-0.5%) and Spain (-2.6%). The UK is however still going strong (+35.7%). There are some smaller countries that have huge increases, but they came from next to nothing. Resulting together in just a tiny growth.
The small country that I live in, Belgium, has a growth rate of -4%. It has to do with the lowering and then finally the cancelling of the feed-in tariff (“green certificates”) for small installations in 2014. That had led to a nosedive in the number of new small installations and many solar panel installers went bankrupt. It shows in the figures from 2015 on: these stayed at 0.7 Mtoe in 2015 and 2016 (with the small loss in 2016, not visible in the number probably due to rounding).
The feed-in tariff is declining in Germany and the same seems to be happening there too.
Back to the original question: can Europe quit fossil fuels thanks to solar energy? That seems to imply that the share of solar energy is/would be high enough to be able to quit fossil fuels. So how much is the share of solar energy in Europe? I can go back to that first report of BP, which also has the figures of all power sources.
This is the primary consumption of 22 EU member states:
A whopping 75.5% of the energy use in those 22 EU member states still comes from fossil fuels (oil, natural gas and coal), compared to only 8.2% of renewables. Included in those renewables is the 24.9 Mtoe solar energy. This means that the share of solar energy is 1.5% of the primary consumption. That is more than what I expected (I remember that the IEA expected 2.4% of the worldwide energy demand in 2040 will come from solar (only PV though) plus wind).
There is no way that this share of 1.5% is going to make much difference in quitting fossil fuels. Let alone that Europe could quit fossil fuels thanks to it.
Another question: is it even possible to completely quit fossil fuels thanks to solar energy? Solar energy is an intermittent energy source. Its production depends on whether the sun shines and how much. During the night no energy is produced. During the day energy is produced (depending on things like clouds, season,…) with a peak around noon. During summer a lot of energy will be produced, much less in winter (about 6-7 times less, when in fact consumption is highest). To illustrate that with a life example from winter 2016-2017, let’s look at a worse case in winter in Germany (January 8, 2017 via the Agorameter):
During such a day with few sunshine (and few wind), something else will need to jump in and produce that energy. At peak demand (18:00), the capacity of solar was exactly 0 GW, onshore wind 0.365 GW and offshore wind 0.149 GW. Together, the intermittent renewables accounted only for 0.51 GW of the needed 63,108 GW at that moment. January 8 was luckily a Sunday. If this happened on a workday, the discrepancy between renewable production and total demand would be even higher. In this case the backup power sources had to fill in 62.60 GW (or 99% of what was needed).
This shows that solar energy alone is not a good energy source to replace fossil fuels, even not in combination with wind energy. Backup infrastructure with dispatchable energy sources is needed with almost the same capacity as the share of those intermittent sources (not necessarily always spinning, but available during winter → a double infrastructure should be build/maintained).
How was that 99% filled in? There was some hydro (1.455 GW), some biomass (5.372 GW) and pumped hydro had a short boost (3.65 GW). The brunt of the demand was filled in by nuclear, natural gas, hard coal and biggest share was lignite (in that order), so 83% of the demand was filled in by conventional power sources.
In the current situation, fossil fuels are still needed to balance the grid. Maybe it is possible to balance it with large amounts of pumped storage in the future, but this will be very expensive and Germany already has the second highest energy prices in Europe.
The twitter tag “#ParisAgreement” is a bit of a mystery to me. As far as I know, the Paris agreement is a non-binding agreement in which expectations were dropped to the lowest common denominator and no pathways were imposed or enforced. By the way, nor Europe, nor the United States mentioned solar in their INDC (Intended Nationally Determined Contribution) declaration. From memory, only Nauru did. So I am not really sure how the Paris Agreement tag would fit in here.
Concluding. On the one hand, I acknowledge that the statement, as made in the tweet, is logically correct: if a region with less sunshine hours is able to quit fossil fuels thanks to solar energy, then yes, it follows that another region with more sunshine hours can do the same much easier.
On the other hand, I doubt the significance of such a statement, knowing that this region with less sunshine only has a share of 1.5% of solar energy (compared to the fossil fuel share of 75.5%) and solar energy is expected to stay in the single digits in the next decades.
Not sure whether I have to classify this tweet under the category “motivational messages” or the category “wishful thinking”.