They have the advantage of being much cheaper to manufacture, but I don't know how their energy density stacks up.
Also, Donald Sadoway is a great teacher.
The problem, near as I can tell, is that even with the benefits, vanadium is still too expensive. It would cost ~$80,000 or more in conc. vanadium for storing 100 kwH - just enough energy to keep a house safely off the grid.
To that price you have to add the solar system to charge it, the cell stack, the conc. H2SO4 you have to dissolve the vanadium in etc.
We need to get way cheaper then that before we can get serious about this - ideally cheap enough that we can encourage everyone to have a cell stack in their house that offsets their peak loads. That would open up some real options.
“The juvenile sea squirt wanders through the sea searching for a suitable rock or hunk of coral to cling to and make its home for life. For this task, it has a rudimentary nervous system. When it finds its spot and takes root, it doesn't need its brain anymore, so it eats it! It's rather like getting tenure.”
Why is yet another mineral we have to mine, then presumably buy from an industry that will become another iteration of today's energy giants, the solution?
What is wrong with present methodologies of energy storage? For example using surplus power to pump water up hill, to later recuperate during peak hours? Or heating water? Things of that vein that're obviously not efficient, but trivial enough to implement for single buildings (whether a house or a sky scraper) without needing any change to infrastructure.
To be clear, what I'm against here is the creation of demand for yet another substance we'll despoil the planet some more for. Mines are festering wounds upon the planet. And I seriously doubt harvesting sea creatures will lead to anything more than the same sort of damage inflicted upon a seabed already scarred by dragnets.
Edit: From reading further, and to answer my own question, the problem is that all research in this field is geared towards the identification of materials or energy sources that can be commoditised.
Say you want to store 1 kilowatt-hour of electricity (most places in the United States, about $0.12 worth). That's 3.6 million joules of energy. The potential energy gained by moving an object away from the Earth is approximately m * g * h, were m is mass, g gravity, and h height. g is approximately 10, and in a home system let's say h is also approximately 10. Probably less. Then the amount of water you need to move is approximately 36,000 kilograms. At 1 kilogram per liter, that's 36,000 liters or approximately 9,000 gallons. For comparison, that's roughly the size of a moderate swimming pool.
And of course, there are many other problems: converting electricity to pump action to water movement to potential energy back to electricity is not 100% efficient. That much water is extremely heavy; there's a reason swimming pools are often built in the ground. Etc. And all that for just 1 kilowatt hour!
My urban apartment uses O(10) kilowatt hours per day, so even if only a small fraction of that must be stored, my roommate and I would require a swimming pool or three. Hard to find space in a city...this could all be done remotely, but then transmission loss cuts the efficiency further.
O(f(x)) denotes a function that is bounded by a constant multiple of f(x), and really only makes sense in the context of a dependent variable x. (e.g. O(2^x) denotes an exponential-bounded relationship with x).
So O(10) in the above context effectively means your apartment uses some unknown number of kWh.
Key to understanding this: Note that if you graphed out all the above as functions, they would all be horizontal lines.
O is about the kind of function something is, specifically relating to how fast it expands.
Most people use it a little more loosely in conversation. More than 1, not 100, etc.
(Note that I'm certainly familiar with orders of magnitude, just not this notation for them.)
"The detector is measuring eV, but this effect is ~ meV |O(meV) so we won't see it."
I don't know a better shorthand for "of approximately the same order of magnitude." There's ~, but it also has its problems...if I say "I am ~175cm tall," I am not allowing for the possibility that I am 100cm tall or 500cm tall.
Is there an established convention?
So basically the point is that Vanadium presents the most efficient method of power storage we know of to date?
About the only problem with PSH is need for a reservoir and hence site selection. In Europe, it is said that Norway, which has lots of good sites for PSH, alone, can support entire energy storage demand of Europe. As I understand it is more problematic in US.
someone has already had the idea:
oh here's another one - might be interesting to strap two of these together:
> The low compressibility of water means that even in the deep oceans at 4 km depth, where pressures are 40 MPa, there is only a 1.8% decrease in volume.
With some simplifications, the stored energy is approximately P*deltaV/2 (when P>>1atm), where P is the pressure and deltaV is the volume change. So in 1 litter (1/4 galon) at -4Km, the energy is only 400J (.1Wh), and you need submarine grade technology to store it.
The potential energy of 1 litter (1/4 galon) of water at 40m (130 ft, a 15 story building) is also 400J (.1Wh) and is much easier to build.
Inefficient storage is pointless. If it ends up being cheaper to throw the surplus away and then later run a fossil fuel generator, people will do that.
Time-shifted heating has long been a thing in the UK; "Economy 7" electricity is cheaper at night, used in conjunction with oil-filled storage heaters.
"Pump water up hill" requires a suitable hill. There are not nearly as many of these as you think, and flooding them is environmental damage of its own.
There's also a difference between using a substance re-usably for energy storage, versus extracting a non-renewable resource and burning it.
Grid-scale batteries are key to getting to a situation where most energy is renewable. The other tech that might work here is the molten salt battery, but that's harder to handle and doesn't scale down well.
The case for small scale electric storage seems less obvious to me https://en.wikipedia.org/wiki/Molten_salt_battery#Vehicles but lithium ion seems to be working for now.
Vanadium is also present in bauxite and in fossil fuel deposits such as crude oil, coal, oil shale and tar sands. In crude oil, concentrations up to 1200 ppm have been reported. When such oil products are burned, the traces of vanadium may initiate corrosion in motors and boilers. An estimated 110,000 tonnes of vanadium per year are released into the atmosphere by burning fossil fuels. Vanadium has also been detected spectroscopically in light from the Sun and some other stars."
"Vanadium metal is obtained via a multistep process that begins with the roasting of crushed ore with NaCl or Na2CO3 at about 850 °C to give sodium metavanadate (NaVO3). An aqueous extract of this solid is acidified to give "red cake", a polyvanadate salt, which is reduced with calcium metal. As an alternative for small-scale production, vanadium pentoxide is reduced with hydrogen or magnesium. Many other methods are also in use, in all of which vanadium is produced as a byproduct of other processes. Purification of vanadium is possible by the crystal bar process developed by Anton Eduard van Arkel and Jan Hendrik de Boer in 1925. It involves the formation of the metal iodide, in this example vanadium(III) iodide, and the subsequent decomposition to yield pure metal."
So not only is extracting this stuff going to involve mining, the process of extraction itself relies on extremely toxic substances, and the most economic areas to mine it are places it's less than prudent to rely upon economically (China, Russia, South Africa)
The big reason pumped storage isn't more prevalent is that it isn't all that trivial to make it economical (you need a big reservoir to have much capacity). You also end up needing a lot of concrete, which also comes from mines (and requires a bunch of energy to produce).
The better tradeoff is probably to examine and carefully control mining practices (as opposed to sort of endorsing the status quo material consumption).
>Or heating water?
This is thermodynamically ridiculous. There's huge energy losses involved, cf Carnot efficiency of such a system.
>From reading further, and to answer my own question, the problem is that all research in this field is geared towards the identification of materials or energy sources that can be commoditized.
Oh please. It's a difficult problem. If there was an easy way to solve it cheaply without consequences it would have been done already. There are problems with dams and hot water and "layman" solutions like those. There are also problems with compressed air, batteries, and molten salts, not to mention loopy stuff like superconductors and nanosprings.
This might be viable for mass-production.
The latter statement is incorrect, but it's an easy to make mistake. What he probably meant was that "in one tank, the vanadium releases electrons, turning from blue to yellow while in the other tank, vanadium accepts electrons, turning from yellow to blue."
One _or more_ are incorrect :)
Peak in the UK is early evening, when people are still working late & also people returning home (electric trains), heating houses, dinner, doing laundry etc.
This means we have to overbuild wind capacity by a factor of about 3 to 4 in order to match nuclear / coal / gas.
Now have a think about how much steel and concrete are required to build 1GW of wind base load capacity compared to 1GW base load nuclear. You need to build, say, 3x 640MW reactors to achieve 1GW continuous output, so 1 reactor can be offline for refuelling or maintenance at any one time, while the other two are run at 80% capacity. To achieve 1GW of base load wind you need to build 3 to 4GW nameplate capacity, and even then the wind doesn't blow all the time, so you need widely dispersed wind, plus storage because sometimes the wind doesn't blow anywhere in the UK for days on end - the currently weekly graph shows this: wind has been producing approximately 0GW output for most of the last week. Also, wind needs long new transmission lines, (large) nuclear can be a drop in replacement for existing coal plants as they are retired, or built next / close to existing transmission lines.
There are plenty of resources on the web that will help you discover the materials inputs for different generating technologies, see bravenewlcimate.com particularly  for example.
Regardless of what technology we choose moving forward, to achieve zero emissions by 2050 would require a war-like rollout, starting now. But wind and solar are at least a couple of magnitudes of order more materials-intensive than nuclear / coal / gas for the same base load output. And there probably aren't that many sites suitable for wind, especially ones that don't require 1000km new transmission lines.
I'm not against renewables per se, I'm just for math. The idea of 'renewable resources' appeals to me. But until the math magically changes, I don't see how wind and solar (with or without storage) is a good idea, either environmentally from the materials-input perspective, or economically from the end-users perspective. What we need to push us forward technologically is large amounts of cheap / free zero emissions -when generating- electricity.
Another strike against wind and solar is this: if either was so attractive economically then large investment funds would have flooded the market with the technology. But it isn't, which speaks directly about the ROI (Return on Investment), which is derived from materials input and running cost per dollar return. The only way it makes sense economically to build wind and solar is if the price of electricity goes up, which is ideal if you want people to freeze to death or die of heat stroke, or make your electric car uneconomical to run.
I think that UK National Grid Status webpage is the best example of wind not working as a solution to electricity supply, unless you define the problem as "how to make expensive unreliable electricity" a la Germany and Denmark , who have the highest wind electricity generation in Europe and the most expensive electricity in Europe .
I may have waffled on more than I originally intended.
Edit: speeling nd grama
What about tidal power? That should work well in the UK.
I recommend reading this book: www.withouthotair.com/ it contains nice estimates of energy used by UK people on the one hand, and energy available from various sustainable sources.
Related video: http://www.bbc.co.uk/britainfromabove/stories/people/teatime...
Yes, it's heavy for the capacity, but this does not matter for fixed installations.
Number of charge cycles & recycle-ability makes an enormous difference to the balance of systems cost for a battery.
Could you charge it up in one location, and truck/ship/pump it somewhere else for consumption? Imagine refitting crude oil supertankers to handle the acidity and ship solar power from some remote coastal desert to more useful places. Other than the headmelting price of Va, it could conceivably be cheaper than building transmission lines & their associated resistance losses.
(I'm probably missing some key fact of why this wouldn't work. But it's a nice idea)