well, assuming scotland doesn't leave...
The United Celtic Republic of Scotland and Ireland (and Wales?) will be more than happy to export angular momentum to its less enlightened neighbors.
Giant flywheel project in Scotland could prevent UK blackouts
31–40 of 113 posts
Re: Giant flywheel project in Scotland could prevent UK blackouts
#32Why do we care about keeping frequency stable when more and more products simply put the power through a rectifier to turn it to DC? The lamps all have LED "bulbs". The computers have power bricks.
Do we really care if the compressors in the air conditioners and the refrigerators turn at a slightly different rate? Okay, maybe a rapid shift in frequency could be damaging, but a slight drift sounds okay mechanically.
Or am I wrong?
Re: Giant flywheel project in Scotland could prevent UK blackouts
#33I don't really know a lot about energy. Is this similar to something like Energy Vault[0] or is stabilizing the frequency different to storing power for later use. [0] https://www.youtube.com/watch?v=gn5AM75AGvw
This energy vault device will not work for a couple of reasons.
Like the astonishingly low energy density of such a structure or the difficulty in running and maintaining the cranes to pull the weights. It is basically a mechanical version of pumped hydroelectric energy storage; just clunky and inefficient.
Flywheels store orders of magnitude more power per ton and have very low reaction times (in the order of milliseconds).
This makes them great for frequency control which just means really short term energy storage.
The power grids frequency is directly co-related with the power throughput. If there is too much demand the frequency will drop.
A flywheel can quite easily buffer very short term demands and flatten the somewhat erratic output of wind turbines or solar.
Re: Giant flywheel project in Scotland could prevent UK blackouts
#34> This is the first time a project of this kind will be used anywhere in the world and ESO believes it could be a “huge step forward” in running a zero-carbon electricity grid. I'm trying to find some stats on this, because flywheel UPS aren't a new idea: https://www.finning.com/en_IE/products/new/power-systems/ele... https://en.wikipedia.org/wiki/Flywheel_storage_power_system#...
What is different in this case is it is not really an energy storage system (at least that is not the main intended purpose), but only to provide stability to the grid frequency. A huge flywheel in a vacuum to provide a reference to millions of distributed PLLs. I don't think the idea is to always have it spin at a fixed rate with minimal losses. In the case where a flywheel is used as a UPS, the rate at which it is…
You can get constant spin rate but variable energy storage / release by adjusting the moment of inertia, e.g. if you have movable weights within the rotor you can move these inboard or outboard, moving it inboard uses energy while increasing the spin rate, and moving it outboard releases energy while slowing the rate. Using this in combination with "conventional" direct axle energy input / release means you can store or release energy from the system as a whole while also keeping a constant rate (within the bounds of the total energy storage capacity of the system).
Re: Giant flywheel project in Scotland could prevent UK blackouts
#35This is a consequence of the UK having little capacity for pumped-storage, i.e. hydro-electric. We don't really have the height, and we have "areas of outstanding natural beauty" that cannot be built in easily, so we need alternatives to store the energy. The rest of the world just builds a dam, creates a new lake, and moves on.
> We don't really have the height, UK is an island, and you have highlands. Why not make some salt water lakes there?
Have you seen how small the UK is vs. our population density? I highly doubt you could find a site big enough and at the correct elevation to make a noticeable difference.
We're the size of Michigan with 67 million people.
Re: Giant flywheel project in Scotland could prevent UK blackouts
#36well, assuming scotland doesn't leave...
I presume an independent Scotland would still be happy selling power to rUK, I believe France does this currently actually
Re: Giant flywheel project in Scotland could prevent UK blackouts
#37This is a consequence of the UK having little capacity for pumped-storage, i.e. hydro-electric. We don't really have the height, and we have "areas of outstanding natural beauty" that cannot be built in easily, so we need alternatives to store the energy. The rest of the world just builds a dam, creates a new lake, and moves on.
As I understood the article, this isn't about storing energy so much as just stabilising the frequency of the grid.
(Yes, if we used more hydro-electric then that would do the job for us, but it's not the case that we need this in order to store energy).
Re: Giant flywheel project in Scotland could prevent UK blackouts
#38Why do we care about keeping frequency stable when more and more products simply put the power through a rectifier to turn it to DC? The lamps all have LED "bulbs". The computers have power bricks. Do we really care if the compressors in the air conditioners and the refrigerators turn at a slightly different rate? Okay, maybe a rapid shift in frequency could be damaging, but a slight drift sounds okay mechanically. O…
A change in frequency generally changes the efficiency of voltage regulators / voltage converters; over a very large network this can exhibit behaviour that looks a lot like negative resistance, this can induce runaway voltage conditions.
Re: Giant flywheel project in Scotland could prevent UK blackouts
#39Those things have interesting failure modes. Will they have to be buried underground, or is this somehow a solved problem?
What happens if the grid frequency disagrees too much with the rotation frequency of the flywheel, too quickly?
The flywheel disintegrates and turns into a massive spherical weapon of mass distruction?
Like this, but 20x worse?
Re: Giant flywheel project in Scotland could prevent UK blackouts
#40Earlier quoted context omitted.
>The rest of the world just builds a dam, creates a new lake, and moves on. Your wording implies this is better than the flywheel solution - can you elaborate for a layman?
I'm just cynically generalising - the rest of world compared to the UK has typically less stringent planning requirements, and more mountainous terrain. To store energy in other countries (except perhaps Holland..!) you build a hydro dam, and pump water into those dammed lakes using excess electricity to store it up for later release. We have mountains (Wales, Lake District, Scotland), but the likelihood of creating…
> the likelihood of creating lakes for hydro use is close to zero
Yes, because they'd be lochs, not lakes :-)
We already have some (e.g. https://en.wikipedia.org/wiki/Cruachan_Power_Station) and are talking about building more (https://www.bbc.co.uk/news/uk-scotland-highlands-islands-445...).