I read about that about four days ago in a Swiss online newspaper [1] (German). The Lake Constance is a large lake (length 64km / 39mi) carved by the Ice Age Rhine glacier shared by Germany, Switzerland and Austria.
Since November last year a hollow concrete sphere with the weight of 20 metric tons has been sitting on the lake bed at a depth of 100m / 300ft. In times of excess power water is pumped out of the sphere and power is regenerated by inflowing water powering a turbine.
Now they are going to experiment with an even bigger sphere in the sea. Perhaps there will be some differences because of the salt water environment.
These sorts of design would generally cover short term demand as they can be started and stopped very quickly.
Really I think if we were developing an energy mix now, and we had a blank piece of paper, it would read as:
- Modern nuclear for base load
- PV/Wind as much as possible
- A mix of things like this article, vehicle to grid, utility battery etc to cover peak demand
- Back up of gas turbines to be used as last resort
The main problem IMO is that nuclear power was extremely badly managed historically:
- Countries used it as a cover to generate weapons grade fissile material
- Modern designs were not invested in and developed sufficiently
- People have irrational fear of nuclear disasters when, actually, coal kills way more people than nuclear power ever has
As an aside, I went to visit the Dungeness nuclear reactor a couple of years ago, and I strongly recommend going if you live in the UK. It cost nothing and was incredibly interesting/a great experience.
I would also add a note on the bottom of the page to time-shift industrial electricity use to take advantage of new peak energy availability.
If you're going to use a great deal of electricity from the grid but don't particularly care about when, right now it makes sense to shift your use to the night-time, when electricity is cheaper. Solar power inverts this, and encourages more daytime use, and even waiting for sunny days if you have enough flexibility in your schedules. There is an inflection point in the difference between daytime and night-time cost (which we might not ever reach) where it stops being worthwhile to run a third shift at a factory, because the difference in energy costs is more than the cost of just building another factory, in the long term.
So if we rebuilt our civilization to take advantage of renewable energy and solar power in particular, we might find ourselves needing less base load power than we do now.
For storage, PSH[1] while obviously not lossless can deal with excess peak capacity -> cyclical demand in a fairly scalable way and unlike lead-acid, LiCO2/LiFePO4/etc, don't suffer from anode dendrite formation.
I have extreme reverence for Bill Nye as a voice of rationality[0], so when I heard him on a talk show nay-saying nuclear power with his prime argument of 3 failures against ~400 I poked to see what sorts of impact it had. At first glance, a failure rate of of almost 1% is absolutely insanity. Things have significantly changed, however, since the design of Chernobyl. Control technologies had progressed in modern (3rd and 4th generation) nuclear power plants, which are safer and cleaner by quite a bit compared to what the 60s hippies were riled up against. (In fact, there are 3rd generation plants that can be powered solely off of the waste-materials of ~7 older plants, providing an auxiliary benefit of consuming spent-fuel rather than having to can->seal->bury). The important thing to consider is that as technology progresses, we (humanity as a collective) should revise our expectations. After all, we don't factor the failure rates of Wright brother era endeavors into Boeing numbers.
Either way, seeing that segment got my curiosity fired up enough to begin some inquiry. (Standard caveat of "everything that follows is armchair"; this isn't even close to the field of study I'm well-versed in. The closest I get to energy professionally is low-voltage/low-amperage li-ion power control, spun such that units pass UL/CSA.) Were his fears founded/relevant to modern nuclear power sources? Were his fears a product of him living through the Cold War as well as living through all 3 of the major disasters that made his fears more emotional than my own? (I.e., he's in his early 60s and lived through the media coverage of 3 mile, Chernobyl and Fukushima[2] which would have impacted his opinion; I'm about to hit 30 and only Fukushima impacted my perception so my fears might be assuaged easier than his.)
I turned to full-cost accounting (from drawing board to decommission; factoring materials sourcing and the ecological impact (e.g. Aluminum takes a lot of power to produce); factoring in transport of sourced materials; maintenance (operational/preventive and modeled failure red-tag fixes); waste disposal) makes nuclear look somewhat appealing, even compared to PV/wind (typically deemed it's closest competitor). As one would expect PV/wind/hydro/thermal/nuclear all score about the same (give or take 50% for all of those technologies), while conventional non-renewable hydrocarbons operate within the next order of magnitude up.
So where does this leave us? Well, certainly there's agreement that fossil fuels/hydrocarbons should be phased out sooner rather than later[4,5,6]. From the damage done to the coal miners lungs, to the carbon impact they're about an order of magnitude less efficient (half-an-order with newer processes to reclaim heat excess and spool up turbines, not unlike using your cars' exhaust volumetric flow to spool up turbos as a form of auxiliary power).
Similarly, those super-tankers that get our iPhones from Foxconn to California off of diesel are doing quite a bit of damage[7] as well. Russia is still using nuclear power for their ice-breakers in the Arctic without incident. I'm not sure how close to catastrophe those units are, but all of the active US Navy combatant submarines are nuclear powered. I'm sure those sailors are thankful they don't have to drink water tainted with diesel as they did in years-yore. I wonder if anyone has conducted viability studies re: utilizing the same power mechanisms that fuel the sub props for those super-tankers (genuinely not sure - if anyone has more information, hit Reply).
Apples to apples (e.g. they both happened within a few years of each other) - the Deepwater Horizon had a catastrophic impact on our ecology. I'm not sure how bad the long-term ecological impact was compared to Fukushima, but I know after a "BP cares" PR campaign, we got right back to business as usual -- we're still pumpin' that black-gold - no one shutdown any hydrocarbon based operations as a result of the catastrophe. The only reason I can think of Fukushima having such a large impact is the historical weight "nuclear power" is burdened with. Someone needs to bring in a PR firm and come up with nuclear's equivalent of "clean coal".
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[0] Shills on Fox News show up as guests frequently and try to attribute climate change to 'natural cycles in the world' using cherrypicked data (say: CO2 statistics from a selected 7 year period). Nye elegantly anticipates these arguments (not too hard, I suppose, since there are a finite number of them) and then contextualizes them (e.g., bringing out a graph showing a 100 year period). Go watch it on youtube, it's quite entertaining and a very elegant way of argumentation that's accessible to the "Glen Beck" demographic [using pretty charts instead of a chalk board].
[6] https://www.brookings.edu/blog/planetpolicy/2014/05/20/why-t... (Standard full disclosure any time I cite a source that's not purely academic/where conflicting interests may exist: Brookings is a "liberal" think-tank. Even though I agree with most of their publications, I don't think they should have an .edu any more than the Cato Institute should.)
[7] https://www.quora.com/Is-it-true-that-the-15-biggest-ships-i... This question was posed in response to a Daily Mail (UK) article that was sensationalist-journalism. The Quora response is of far better quality and addresses the nuances with significantly more insight than the original article.
>I wonder if anyone has conducted viability studies re: utilizing the same power mechanisms that fuel the sub props for those super-tankers (genuinely not sure - if anyone has more information, hit Reply).
They didn't just do a study, they actually built a nuclear-powered cargo/passenger ship many years ago, called the NS Savannah. It was a commercial failure. That's not the only nuclear-powered merchant ship built; Germany built an ore-carrying ship, and it only ran for 9 years. Japan built one too, and it was a failure on its first voyage.
The second article here thinks the Savannah was doomed by other factors, and tries to argue that maybe nuclear-powered merchant ships should be tried again, but there's a lot of problems with the idea. Past ships had problems with radioactive waste being dumped into the sea (which caused fishermen to refuse to allow the Japanese ship to even dock). It takes a lot more crew to staff a nuclear ship, and they have to be highly trained. They'd probably be a terrorist target. The shipping industry (maintenance, etc.) isn't set up to handle nuclear commercial ships. The insurance would be prohibitive. Overall, it's really questionable whether it'd make economic sense to have nuclear-powered commercial ships.
Base load in Germany is about 50GW, around 10GW of which is handled by wind and water. That leaves approximately 40GW to be handled by other means.
At 20MW per sphere, you need 2000 spheres to cover the entire base load. (Not sure where the article gets its 80 spheres number from, did I make a mistake? There's an order of magnitude difference..)
These spheres don't generate electricity, so you still need other (less constant) means of electricity generation. Germany generates solar electricity peaks of 50GW, so perhaps tripling that capacity could get them close.
Wind energy is around 20GW, but way much more constant, so tripling that could also get them close, and you could possibly do with a lot less spheres, perhaps closer to the 80 in that article.
So with a triple investment in green energy and the building of hundreds of these spheres, Germany might be able to make themselves a 100% renewable energy country. (Assuming my assumptions are close to reality)
Don't mix MWh and MW (it's commonly used to mislead, but not here). The article is declaring 20MHh of storage while using 5MW power turbine. 5MW output from 20MWh storage gives you 4h output.
Edit to add: If you want to make proper calculations, don't forget that these types of storages are very inefficient. You can't compare them with pumped hydro.
Ah thanks, I misread that. I get that these types of storages are inefficient, that's the point I was trying to emphasize, a solution like this looks interesting, but it's not a serious competitor to nuclear power, or even pumped hydro (it's basically pumped hydro, but with a human made reservoir).
How can you say that off-hand without knowing what the costs are? It's not at all obvious to me that building 3000 concrete spheres with turbines and a bunch of PV panels is any harder or more expensive than building giant nuclear power plants.
Each sphere is only worth 5 MW (for 4 hours, totalling 20 MW·h worth of electricity). 80 spheres were not meant to cover the entire base load, but just to make them a relevant factor in the grid.
Since November last year a hollow concrete sphere with the weight of 20 metric tons has been sitting on the lake bed at a depth of 100m / 300ft. In times of excess power water is pumped out of the sphere and power is regenerated by inflowing water powering a turbine.
Now they are going to experiment with an even bigger sphere in the sea. Perhaps there will be some differences because of the salt water environment.
[1]: http://www.tagblatt.ch/ostschweiz/Forscher-speichern-Strom-i...