Since this is GQ and not IMHO or GD, let me just say that not everyone thinks that nuke power is the solution to everything. While it does help significantly with global warming, it creates nuclear waste for which there is no good solution. Also, while I do agree that we have improved nuclear tech immensely, as long as we have nuke power we are going to have nuclear accidents. Just because France has managed to go a few decades without one doesn’t mean that they can’t happen.
So in some ways it’s a choice between ruining the atmosphere now or poisoning parts of the earth for tens of thousands of years.
That’s about as far as I want to go in GQ with this, just stating that there are differences in opinion as to whether nukes are actually a good solution or not. Anything beyond that is a topic better suited to IMHO or GD.
Although batteries get all the publicity, when I looked a couple of months ago to see what frequency stabilization was in use, I found what appeared to be several flywheel sites.
Since the mid 80’s, our providers have been very secretive about transmission lines and infrastructure. My working theory is that I never heard about flywheel installations because they didn’t want to talk about it.
A significant problem with nuclear power is that although it is generally very safe, when a disaster does happen the cleanup and other costs are extremely high.
So high in fact that they can’t be insured in any normal way. What private insurer would cover something that could cause a half-trillion dollars in damages, even if the event is rare? They couldn’t cover that even if they wanted to.
The government ends up being the insurer. In the US, this takes the form of the Price-Anderson Nuclear Industries Indemnity Act. Other nations surely have their own equivalents, but even if they didn’t, the government would still act as the insurer under the guise of disaster relief.
There is not yet evidence that improved tech can lower these costs. There are systems like liquid fluoride salt thorium reactors which are, in principle, totally fail safe. But the designs are still decades away from production.
We don’t have time to wait for these advanced nuclear technologies. Fortunately, solar+wind+storage are cheap, don’t have rare-but-expensive failure modes (well, aside from some pumped hydro storage installations), and work today. There will be some adjustment necessary but overall will be a net positive from the current situation. We just need to push on it as hard as we can.
But I’m still a fan, especially since I have some colleagues who are working towards superconducting turbines for wind power, which, among other advantages, would significantly reduce the potential for these kinds of “mishaps”.
My point is that scale matters. The failures here cost a few million bucks. If some worker happened to be unlucky enough to be on the turbine at the time, add another $10M or so. These costs are easily managed by normal insurance, which wind farm operators are already paying.
It’s not possible for a wind farm to fail in a way that it costs hundreds of billions of dollars. The same is not true of nuclear power. Therefore the government acts as the insurer of last resort. Which means the taxpayers are really shouldering the risk burden here, not the nuclear plant operators.
I had skimmed the Wiki and was left still not understanding why they are not used at utility level more frequently. The quote from the link refers to smaller flywheels with lighter mass, not utility application ones. From the Wiki for utility applications what’s not to like?
On preview, maybe they’re used more than I appreciate.
They aren’t that secretive. I’m aware of one in New York and another somewhere in Europe.
They don’t get as much press because they are only used for stabilization. They aren’t used for longer term storage like pumped hydro storage. Flywheels can handle things like the variations in wind speed that give wind farms such variability, but they can’t handle things like solar power only working during the day.
If they can develop better flywheel systems that can compete with things like pumped hydro, then you’ll definitely start hearing more about them. Pumped hydro isn’t practical in a lot of areas.
Poor energy density, mostly. As it turns out, the maximum possible energy density of a flywheel is equal to half the specific tensile strength of the construction material. Carbon fiber has a specific tensile strength of about 2500 kN-m/kg, and half that is 1250 kJ/kg.
That compares to around 875 kJ/kg for lithium ion cells. But it’s only counting the outer hoop of the flywheel, and ignores:
The rest of the rotor, specifically the hub and “spokes” (whatever we call the support between hub and hoop)
The casing, which has to hold a hard vacuum and contain a failed rotor
A bearing system, which will almost certainly have to be magnetic
A generator, needed to actually turn the kinetic energy to electricity
In practice, these elements add up to a large factor, >>10x. So compared to batteries they do very poorly. Flywheels do have the advantage of high power density, but a large enough battery bank has a high power capability as well. Maybe when carbon nanotubes are cheap and ubiquitous, flywheel storage can be reevaluated.
Slightly larger footprint compared to some battery technologies. A 20 foot container can hold 60kW/240 kWh storage, and generally this is placed in a concrete vault for safety
Risk of mechanical failure – though insignificant, there is a risk of mechanical failure. Our technology uses all-steel construction using appropriate alloys to ensure that the components do not disintegrate under use and stress, unlike carbon-fibre alternatives
Lower peak power rating – the technology is currently standard with a peak 30 kW power rating, reducing its effectiveness as a short-term peak power support case
Relatively higher self-discharge – although the charge can be stored for hours, not minutes like other mechanical solutions, it is not a medium or long term storage solution for weeks without use.
Heavy – these units are heavy at over 10 tonnes each and therefore are only suited for stationary applications
Short answer- they are still a little bit worse than batteries for applications like evening out solar power. At scale, a little bit worse can translate into a big cost.
When evaluating energy storage technology for a given application, the primary considerations are:
How much energy can be stored (per kg and/or per cubic meter)
How fast can energy be taken in from a source
How fast can energy be supplied to a load
What is the cost of the technology when scaled to the application
The constraints of the application will determine the “goodness” of the technology. There really aren’t very many “always bad” technologies out there. That’s why there are compressed air facilities in caverns for huge, relatively cheap energy storage with long, slow time constants.
And I’m aware of Transmission lines around my state, as well as close to my home. But my state electricity commission hasn’t issued a map showing transmission lines since the the early 80’s, and they don’t issue press releases about critical grid infrastructure.
What I was not immediately getting is how the installation costs increased with the disadvantage list of flywheel storage for some applications.
FWIW I’ve found the following which is amazingly detailed discussion of the various alternatives, current state of the art, and prospects in the near term.
