Can we stop with these convoluted systems and just do nuclear already?
Regardless of your thoughts on Nuclear, this is clearly a much simpler device. Also, I suspect the failure modes in this are pretty boring ...
Also this does not seem very convoluted, it's using an electric engine pretty directly. If you are actually boring straight down it seems like the failure modes are pretty okay.
Why? Just build more. Keep expanding capacity so the base load covers the peaks and thensome. Push the price of electricity down while keeping it carbon-neutral and crush competition. Get everyone 2c/kwh power. Wouldn't that be more fun?
If you don't know anything about how a grid functions then maybe you should stop shoehorning a single solution to solve every problem when everyone is already aware that a large array of different technologies is necessary for a modern grid.
Demand response, frequently promoted as a way to increase penetration of intermittent renewables, can also be used to reduce the cost of a system composed on high capital cost, low marginal cost dispatchable generators like nuclear. Charge the EV's and run heat pumps to warm thermal storages during the night when demand is lower, say.
Also, it means you have to run your reactors regularly at below 100%, so you still can react on additional demand, which increases further the cost of a very expensive technology.
IIRC that 5% figure I read was wrt EPR and AP1000, presumably older generation LWR's are slower, by how much I'm not sure. France has run older generation PWR's in load-following mode for decades, but I'm not sure which ramp speeds they achieve; fast enough in practice in any case it seems. CANDU reactors in Canada have steam bypass and can apparently ramp at >10%/min.
In any case, my point is that ramp speed is in practice not a technical limitation. Of course you want to run a generator with high capital cost but very low marginal cost at 100% as much as possible, but if you now and then need to ramp (say, if the wholesale price goes negative) you can do it.
> Also, it means you have to run your reactors regularly at below 100%, so you still can react on additional demand, which increases further the cost of a very expensive technology.
To be clear, I'm not advocating a 100% nuclear grid. I'm just pointing out that the "nuclear can't ramp and is thus unsuited for the grid of the future" isn't correct. In particular, I think solar and a moderate amount of storage is very well suited to cover the daily variation in many parts of the world. I also think that dispatchable low-carbon sources (which could be hydro, or nuclear, or something else like geothermal where available, CCS where geological formations for storing CO2 are available, etc.) have a role to play in least-cost deep decarbonized grids. See e.g. https://doi.org/10.1016/j.joule.2018.08.006
AFAIU France primarily uses reactors which are earlier in their fuel cycle for load balancing, and ones which are near the end run with a flatter profile.
Didn't know about specific as it's not really my area, but would running a PWR with very high enrichment level (AFAIK some designs use 93% U-235) allow quick spin down and spin up?
Well.. there are a lot of factors in a reactor design affecting the ability to increase or decrease power quickly. Geometry, fuel/moderator ratio, fuel density, burnable poisons (for flattening the reactivity swing over the fuel cycle), amount of control rods etc etc. Fuel enrichment being only one thing, which in turn affects other things as well (e.g. reactors using highly enriched uranium tend to use different fuel designs than low enriched fuels).
But yes, military reactors for navy ships obviously have very different demands on them than civilian power reactors, and are designed accordingly.
And yes, while US navy reactors use 93% enriched fuel, it's not necessary, e.g. French and apparently Chinese submarines use low enriched fuel (7% for French).
Which "funnily" enough makes it so that the more dangerous reactors remain in use for longer, as the new designs aren't built, despite huge safety improvements (even if you go just for late 1970's self-sealing molten lead/bismuth reactors).
Overcapacity is a problem, especially for low-enriched reactors, but that's why it shouldn't be the only answer.
> the waste problem.
Ehh, it's well managed in Canada and France, I don't see why Americans can't handle it. Just keep it away from fault lines, right? I bet some of those old missile silos would be perfect.
And please enlighten me, how does France manage their nuclear waste problem?
And those hard-to-use fractions aren't going to be a problem for long, pretty sure they are considerably shorter-time risk than the timeframe for cleanup of WW1 battlefields in France (which currently stands at around 700 years).
Energy storage has also been planned for nuclear power plants as starter and emergency power.
Most people just don't want to accept the fact that when it comes to energy density, nothing compares to nuclear. Nothing even comes close.
I do have high hopes about fusion and molten salt thorium is also up there as something I'd like to be further explored.
But currently nothing up and coming seems to compare to nuclear.
I just did a quick skim of the wikipedia page of that 'hydrino' stuff: https://en.wikipedia.org/wiki/Brilliant_Light_Power#Criticis....
I'm not an expert, but reading those criticisms makes me think this is nothing more than a money grab scheme without delivering anything usable for the past 30 years.
Also, this thread: https://news.ycombinator.com/item?id=24423103