One of the things many environmentalists have seized on with excitement in recent years is Germany's announcements about phasing out nuclear power in favor of wind and solar.
After beginning this "Energiewende", we immediately saw some years with high German CO2 emissions, though just recently, in 2014 there was a drop (and that was apparently due to a mild winter, leading to a reduction in use of coal for heating).
Many pro-nuclear people like myself have been presuming the case in Germany is much like the case in Japan, where suddenly shutting down all of their nukes at once immediately jacked up their CO2 emissions.
The German case, however is different in that they're still running a number of nukes, they're just planning on shutting them all down by 2022: this is a more gradual phase-out. And German CO2 emissions aren't dominated by the power-sector (which only make up around 20% of the total) though the announced figures CO2 emissions that you hear are typically for the country as a whole, not just for the power-generation.
So, if we're interested in what the German example shows about substituting renewables for nuclear power, we need some more information. Let's see what's out there...
There's this chart from the wikipedia page Electricity sector in Germany:
This is a graph of data available from the
U.S. Energy Information Administration (EIA). This graph only goes up to 2012, though the EIA now has data up for 2013. And some numbers have been announced for 2014, but they haven't made it into the EIA dataset as of yet.
I haven't crunched this information yet myself, though there are a number of posts out there by other people, such as this fellow who seems very pleased to announce that the CO2 emissions from the German power sector has declined slightly in 2014 (whereas someone like myself would've expected them to go up)-- but it appears that the main reason they came down is that Germany burned a bit more of a cleaner variety of coal and less of the really dirty stuff. That may count as progress but isn't anything to get excited about if you're interested in the Nukes vs Renewables question.
Anyway, back to that chart of EIA data. The anti-nuclear folks point to this data to show that Germany was able to reduce it's use of nuclear, and replace it with wind and solar without increasing their CO2 emissions. You might look at this the other way around, however: Germany hasn't made any progress in reducing their CO2 emissions. If only they'd replaced coal generation with renewables (or for that matter, nuclear power) then they could've gotten their CO2 emissions to actually come down, and that really would be something to celebrate in the fight against global warming.
The standard Green position on all this is that we need to push "renewables" and scale down nuclear power at the same time, and this really does seem completely crazy. They want to fight a two-front war, where one of the fronts might make some sense, but the other looks pointless, if not completely counter-productive (you know, I keep noticing analogies between self-described environmentalists and conservatives...).
In any case, there's a number of things to remember about this data we're looking at there: it's just for electricity generation, and around 80% of Germany's CO2 emissions are from other sources, And Germany itself, while one of the top ten CO2 emitting countries is only ranked around number 6, and the total emissions are dominated by the top two, the US and China. Whatever happens with renewables vs nuclear in Germany, it's significant mostly as an example of what can be done, rather than in absolute terms.
And as you can see in chart of EIA-data, power generation in Germany is still dominated by the fossil fuels, which are the worst from the point of view of GHG (and pretty much any other environmental issue). See my earlier piece Going Nuclear on CO2.
Or consider this piece by Robert Wilson:
An even more sobering comparison, given Germany's much trumped green credentials, is with the growth of coal power plants this decade. At the end of last year Germany had a total of 36 gigawatts of installed solar capacity, and this produced 28.3 terawatt hours of electricity. However, between 2011 and 2015 Germany is opening 10.7 gigawatts of new coal power plant capacity. The consulting company Poyry projects that these new coal power plants will have average capacity factors of 80%. If so, they will have a combined average annual output of 75 terawatt hours. In other words, in five years Germany is opening coal capacity which will have an annual output of more than double that from all of its solar panels. However, this comparison is perhaps too generous. Solar panels typically last twenty to twenty five years, but coal power plants easily last twice that long.
What we are seeing in Germany, then, is much more of a coal lock-in than a solar revolution.
Low Carbon Power
Just to emphasize the point that nuclear power is a very clean, major power source as far as global warming is concerned, here's a report on some work by the Center for Global Development, from 2007, Carbon Dioxide Emissions From Power Plants Rated Worldwide:
Low-carbon power comes mostly from nuclear and hydro plants, which do not emit CO2, but do pose other potential environmental problems.
(Please don't shoot us, we're making appropriate environmentally correct noises.)
The largest U.S. power plant to win a green rating for nearly zero CO2 emissions is the Palo Verde nuclear plant near Phoenix, Arizona; it produces about 26 million megawatt-hours (MWh) of electricity per year. Other large plants that are emitting zero CO2 but produce substantial electricity are:
The South Texas plant in Wadsworth, TX -- 20.9 million MWh
The Limerick plant in Pottstown, PA -- 20.8 million MWh
The Vogtle plant in Wanyesboro, GA -- 20.1 million MWh
The Byron plant in Byron, IL -- 20 million MWh
The Braidwood plant in Braceville, IL -- 19.8 million MWh
All are nuclear power plants.
Total German CO2 in 2014
At first glance, this looks like really good news: Germany's CO2 Emissions Decrease for the First Time in 3 Years:
In 2014, CO2 pollution dropped by around 41 million tonnes, a 4.3% reduction compared to 2013, according to an analysis by the Federal Environment Agency (UBA) from Tuesday (31 March).
The trouble is when you look into the cause:
According to the UBA, the “trend reversal” can likely be attributed to an extraordinarily mild winter. Because temperatures were not as low, less fossil fuels were burned for heating.
We've been seeing an awful lot of triumphalist green-headline writing of late, but as is typical if you look into this one for just a moment, it's hard to see what's so exciting about it.
It might work as a rebuke against a pro-nuclear person like myself who's first guess probably would've been an increase in CO2... but it's not a terribly strong rebuke: Germany may not be an example of a country going in the wrong direction, it is however, an example of a country going nowhere, phasing out one clean energy source and replacing it with another isn't doing anything to restrain burning coal...
I'm still trying to sort out exactly what's going on here... as one might expect, whatever happens with fossil fuels dominates the CO2 emissions.
The decrease was particularly significant for natural gas and hard coal. Natural gas emissions fell by about 12.9%, and hard coal by 8.2%.
Lignite-fueled power, on the other hand, only saw a 2.2% reduction in CO2.
Pumped Hydro Storage
I've seen some recent mentions of the use of Pumped Hydro Storage in Germany, such as this news from February 19, 2015:
Study concludes hydroelectric pumped-storage development should expand in Germany:
Germany’s pumped-storage power plants have a combined capacity of about 7 GW.
And according to this study: Prospects for pumped-hydro storage in Germany published in Energy Policy, June 2012:
Motivated by an ever increasing share of intermittent renewable generation, a variety of energy players considers new projects, which could increase the available capacity by up to 60% until the end of the decade.
So that would take it from 7 GW to 11.2 GW.
I think there are good reasons to be skeptical about claims in this area, but these are at least a sign that they're aware of the main trouble of relying on wind and solar and are looking into solutions.
The magnitude of storage being discussed (only around 11 GW) isn't very impressive though. That doesn't look sufficient to smooth out the power produced by the present-day level of renewables let alone allow for continued growth.
Daily Variations
This is a fun tool that lets you look at the breakdown of power used at every moment throughout a week: https://www.energy-charts.de/power.htm
The days of the week appear immediately as seven humps, where it's not unusual to see solar peeking mid-day, wind making a small constant presence throughout... and most of the power coming from "conventional" sources, fossil fuels and nuclear.
One thing that had never occurred to me before is that wind and solar can roughly compensate for each other: on a clear day, the sun shines, during a storm, you lose the sun but the wind picks up. I think you can see that happening near the end of week 36, for example.
But if you go back to the beginning of the year, around week 1, you can see that solar power doesn't do you much good in the middle of a German Winter. Then it's all wind plus conventional.
One thing I would've expected to see is that solar power would have an advantage on the leading edge of a peak, but decline on the trailing edge... but I don't see any visible symptoms of this in these graphs.
There are some peculiarities about the German energy market that might very well effect this usage pattern though...
Mandatory Purchase
An article at The Economist (yeah, I know) talks about current German energy policies:
The Energiewende has two main policy tools: generous support for renewable sources of energy, and an exit from nuclear power by 2022. The government supports renewables by promising those who install solar panels or finance windmills a fixed, above-market price for each kilowatt-hour of energy they feed into the grid. Those renewable sources have grid priority, meaning they must by law be drawn upon before other energy sources, like electricity from coal, gas or nuclear plants.
... the prices paid by consumers have been rising. This is because of the above-market prices guaranteed for renewable energy. On a sunny, windy day, a flood of renewable energy surges into the system; it must be, by law, bought by grid operators first, with the producers paid those above-market rates. Those rates are subsidized by a surcharge on customers, and the surcharge must go up when more renewable kilowatt-hours are poured into the system.
They then go on to talk about how this lets wind under cut natural gas and encourages utilities to burn more coal, but if that makes any sense, The Economist did not succeed in explaining it to me. I don't think we're seeing any overall increase in coal burning at present.
Update: Why are they doing this? What should we all do?
Why are they doing this?
The social backdrop behind Germany's turn against nuclear includes some massive public protests in 2011, right after the Fukushima accident:
There were some really remarkably alarmist headlines in those days. Consider this one: Severe nuclear reactor accidents likely every 10 to 20 years, European study suggests.
This story is based on a study from the Max Planck Institute, which counted Fukushima as three incidents-- even though the source of the problem was a single design flaw in the backup power supply shared by three plants at one site.
And I can't say I understand why someone living in Germany wouldn't regard the French experience with nuclear as being more directly relevant.
What we should do...
I was asked what I think we should do considering the (relative) lack-of-interest in expanding nuclear capacity at present:
(1) We need to stop giving fossil fuels a free-ride, and hit them hard with a carbon tax or a cap-and-trade scheme-- it looks to me like Obama's Clean Power Plan may be an excellent first step (see my earlier piece).
(2) Nuclear power continually gets sand-bagged by protests from very alarmist environmentalists, and we're going to either need more intelligent environmentalists, or a more intelligent public that ignores them when they're being irrational.
So, all we need to do is increase the collective intelligence of humanity.