Headlines this week about US and China goals to triple renewable deployment globally by 2030.
With nuclear stumbling, it’s never been more clear that any zero carbon scenario requires a LOT of wind and solar. Solar is easiest to build, but as a new report makes clear, a balance of generation makes most sense.
The global average capacity factor for solar in 2022, according to BloombergNEF data (which may well exclude some small-scale generation), was 13.2%, assuming the average new solar farm came online mid-year. In contrast, wind farms had a global average capacity factor in 2022 of 27.2% by the same methodology. Hydro plants ran at a global average of 40% in 2022, and geothermal at 68%. While new wind and hydroelectricity plants are likely to produce more electricity per megawatt due to technology improvements, low capacity factors are a structural feature of solar.
Solar is cheap (it is usually the cheapest source of bulk electricity) and easy to site, making it a quick technology to deploy. Tripling global renewables capacity by 2030 could be achieved with solar alone. However, because of solar’s low capacity factor and high seasonality, a rapidly- decarbonizing world that is overly reliant on solar while tripling renewables capacity will not see the same impact on electricity generation, nor emissions reductions, as one with a more diverse fleet of renewables.
There is even some danger that high solar generation in the daytime and in summer could cannibalize the returns of other clean power plants such as wind farms, preventing build and driving more fossil fuel use at night and in the winter. Addressing emissions requires a balanced deployment of clean power technologies, and consideration of the time of day and year when different sources are likely to be available – not merely tripling the capacity deployed. Wind and solar often have complementary output profiles, and solar generates more at times of year when hydro generation is often low. A mixed portfolio will also make it easier to remove the last 10-30% of emissions from the power sector.
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Dark Horse? Enhanced geothermal – see below:
German Chancellor Olaf Scholz together with the state premier of Bavaria, Markus Söder, during a visit to the construction site of the pioneering Eavor Loop ‘closed-loop’ geothermal plant in Geretsried near Munich, has pledged to give a boost to the technology.
The plant that is scheduled to partially start operations next year will generate about 64MW of thermal power for heating and 8.2MW of electrical power, from four of the closed loops by Canadian start-up Eavor, saving approximately 44,000 metric tons of CO2 equivalents per year.
Eavor, which has secured backing from the likes of BP, Chevron, and Japan’s Chubu Electric, in 2020 presented its technology based on a closed loop in which cold water — or a similarly behaving working fluid — travels down a 3-5km pipe, then underground horizontally through hot rocks for a few kilometres, up another pipe and along the surface back to the start. The heated-up liquid at the surface can be used for district heating and power generation.
“To use this heat also above ground is so obvious as this heat is always there, independent of wind and weather, independent of the seasons,” Scholz said.
The Chancellor stressed that Bavaria is the focal point of geothermal drilling in Germany, with much of Germany’s 42 deep geothermal plants located in the state. Another 12 are being built, and 82 more are in planning.
But much more is possible, he added, pointing to studies that geothermal could cover a substantial part of Germany’s heating needs.
“Our goal is to tap as much geothermal energy as possible by 2030 and to feed ten times as much geothermal energy into the heating network as today,” Scholz said.
“With nuclear stumbling, it’s never been more clear that any zero carbon scenario requires a LOT of wind and solar.”
And storage (that’s cheaper than peaker plants). Never forget the storage.
The demand curve follows industrial and residential behavior, and even nuclear has needed lots of grid storage (pumped hydro) to make it cost effective to get the most out of its flat production overnight. Shifting grid energy to follow times of demand makes the difference between which power plants are cost effective or not.
We had record high demand for months in Texas under the 2023 heat dome, but between the advantage of having solar farms to the west of our high demand population (peak heat comes hours after peak sun) and the grid storage shifting more power to the evening load we didn’t have to face the expected rolling blackouts.
Engineers appreciate the power of buffering.
The six nuclear plants that Scholz’s government is refusing to turn back on would provide almost exactly as much power as a thousand of these geothermal units – and could easily be tapped to use the cooling water for district heating as well. It’s already being done in Switzerland, and tbe hot water can be piped ~100 km. The 2 US-designed AP1000 reactors in Shandong province, in China, are being linked to heating for a whole city.
“The six nuclear plants that Scholz’s government is refusing to turn back on….”
I’ve long thought that shutting down operational NPPs where no problems have been found was a grossly stupid mistake in the face of global warming. I’ve learned, though, that turning old plants back on is an elaborate and expensive project in itself.
“…and could easily be tapped to use the cooling water for district heating as well. It’s already being done in Switzerland, and the hot water can be piped ~100 km.”
Although I grew up in hot New Orleans (and now live in central Texas), having lived at a school in New England for four years, I appreciate the cost-effectiveness of shared underground heating during the long winters.
“The 2 US-designed AP1000 reactors in Shandong province, in China, are being linked to heating for a whole city.”
I always wonder about the challenges of cooling technology for thermal plants in a warming world, as with how reliable externally-cooled NPPs are doing the increasing heat waves. (Older French nuclear plants had to be shut down when most needed during a heat wave because of overwarm cooling water, for example.)
In today’s crisis, time-to-deployment and carbon payback periods matter a whole lot more than long-term cost-effectiveness. We’ll see if the new German geothermal meets schedule for starting next year (promises, promises), but it seems the carbon payback period would definitely be much shorter than for new nuclear power plants.
There are actually eight plants that could be restarted, from 1200 to 1400 MW each, so considerably more than a thousand of those geothermal plants – and their construction carbon debt was paid off long ago.
The German government claimed that relicencing them would be too difficult, that fuel could not be obtained at short notice, and that they weren’t useful for winter, as gas was needed for heating, not power – all untrue. The regulator declared the plants sound, and one of the operators offered to keep a plant running to provide power for hydrogen, at a kWh cost well below the German mean.
https://www.radiantenergygroup.com/reports/restart-of-germany-reactors-can-it-be-done#:~:text=The%20most%20immediate%20question%20fo
Again, I am for the restarting of functional nukes.
Not sure I’m impressed by Radiant Energy Group (which dances around the fact that it is a pro-nuclear power group, emphasizing “intermittent renewables”) as a source, though. 😉
Even the best-case reactor, as they describe it, will have to start shopping for more fuel pretty quickly. (I didn’t check what flavor of fuel it needs or its current associated supply chain.)
Isar 2 has the most potential for being restarted given its location in a politically supportive region, being owned by operators in favor of life extensions, and currently still holding an operating license. Furthermore, the Isar 2 reactor is reported to have approximately 6 months of full power operation and 3 months of stretch operation left in its current fuel element, with Westinghouse reportedly capable of delivering new fuel elements within 6 months. Without any cause for concern about Isar 2’s fueling its timely restart can be de-risked and the financial cost of restart reduced.
Exactly what diagnosable non-functional problems existed before the disasters at Fukushima, Chernobyl, TMI, Brown’s Ferry, Kyshtym, Tokaimura, Windscale, Indian Point, Hanford, and the hundreds of other disasters and near-misses of all imaginable kinds?
Were there visible foreshadowings ignored by workers or management so we can never trust the nuclear industry’s honesty, integrity, or humanity again? Or were there no signs so we can never trust any reactor or nuclear facility of any kind ever again? Those are the only 2 choices.
A sample: https://en.wikipedia.org/wiki/Nuclear_reactor_accidents_in_the_United_States
Sorry, i just couldn’t ask any of those questions with a straight face.
No, I don’t automatically accept the claims of safety of any industry made by the public relations people, and certainly none from China or Russia, but I’m also aware that a lot of industries have death and destruction rates that blow the doors off of the nuclear power industry, they just don’t make the news. And I don’t know what you’re asking about “diagnosable non-functional problems” since there is extensive analysis of what led to all of those failures.
Also, the fact that you list all of those different designs suggests you think they are all the same technology, when in fact they vary widely, and note that people don’t use candle flames to check for leaks in modern plants. A better argument against restarting the German NPPs would be to compare them to similar designs, and ensure that obsessive-compulsive skeptic engineers are part of the inspection teams.
You should check out the table of “Nuclear and radiation accidents and incidents” sorted by date or deaths:
https://en.wikipedia.org/wiki/Nuclear_and_radiation_accidents_and_incidents
https://www.researchgate.net/profile/Jozef-Misak/publication/272406182/figure/tbl2/AS:668997552984095@1536512854897/rates-for-each-energy-source-in-deaths-per-billion-kWh-produced-Source-Updated.png
I’m just waiting for the massive explosion at the quickly-built LNG port first.
Closed loop geothermal, whatever works. Really whatever works!
Be aware that heat transfer thru rock is slow, relative to human life span, and this system is limited to hot rock around the pipes rather than a larger volume that water can be pumped thru. So, wondering what the efficiency over time drop is.? Did refer to my old thermodynamic text books but found they were now written in sanskrit rather than the original English and am still wondering. Expect the thermal heating value would last along time.
Current geothermal seems to be tailing off over 50ish years – same order of magnitude as many dams silting up, and reactors reaching eol. Reactors should be easier to refurbish though – the pressure vessel can be annealed, the containment is under zero stress, and other components can easily be replaced.
The situation is critical, there is no silver bullet. For reliable power supply a 40% dispatchable level is required, depending on multiple factors. So what works is good, meanwhile, stop pissing & moaning around and build the required nukes.