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Comment by steeve | Hacker News Reader

According to the article, one station is rated at ~100kW (that's maximum power output).

A typical nuclear 3rd generation nuclear reactor outputs ~900MW-1GW.

Assuming an impossible 100% charge (ratio between rated and actual generated power), that's still 10000x (!) less power than one nuclear reactor. Put differently, you'd need 10000 of these stations to generate the same amount of electricity as _one_ nuclear reactor.

Then one needs to consider how long that plant can deliver energy. They don't give concrete numbers for that technology, but again taking nuclear again as an example, reactors are designed to run for a a minimum of 40 years (some reactors are now certified for 80 years in the US). Solar and wind are ~20 years.

All in all, love the tech, but the laws of physics are pretty harsh.

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I've recently become enamored with micro-hydro generation, having seen ways in which it can be totally non-destructive to local wildlife and/or fish going through the generator, and while I completely agree with everything you've said regarding nuclear vs micro-anything, for personal power generation on a farmstead, nuclear is pretty inaccessible.

On the other hand, this guy's[1] manufactured a micro-hydro 2km drop generator capable of producing 5-12kWh per day for ~$50 in parts (turbine 3D printed). That's of course limited to drop power (meaning you have a high body of water and a low body of water and generate power, like a dam, by capturing energy from passing the falling water between them through a turbine) but for relatively level bodies of running water (read: creeks, streams, etc) a small, non-destructive weir dam can capture 100kWh per day from a single diverted turbine if conditions are good.[2]

Of course, conditions aren't always, and not everywhere has access to any immediate water supply from which to generate power, but it seems to me that for those places that do, capturing their own power via micro-hydro frees up other generated power for the folks that don't -- but that might be a naive view.

[1] - https://www.youtube.com/watch?v=1KyL1-0A0Gw&t=2s

[2] - https://www.youtube.com/watch?v=61lZn1sUkzE&list=PLtTypVpmDd...

Yes, this is exactly what a dam is (pumping or releasing, or using rain).

Hydo is very cool, and very green.

Some things to remember, however:

- need to drown whole valleys (very high impact on local wildlife)

- energy density is not that good (i don't have the numbers but the volumes of water moved are huge, hence dams)

- very rapid piloting and low maintenance, so nice to absorb spikes

> Hydo is very cool, and very green.

Well, maybe. I think this depends on what you mean by "green". If you mean low on CO2 emissions, then sure, but we need to consider habitat loss, methane emissions from decomposition, and the possibility of triggering earthquakes. Hydro is also quite expensive to build, and often requires seizing land through processes like Eminent Domain (in the US).

You are right, I was meaning green in the sense of gCO2eq/kWh.

Hydro may require drowning valleys, but micro-hydro with a weir utilizes existing waterways with minimal impact. As to energy density, there's no fixing that, but for most people, density is far less a concern than 'enough' -- solar isn't a viable solution for my current household because it would require clearing enough trees that it feels counterproductive. So, I can go with solar, but I couldn't be self-sustaining on solar.

For most people, that's not a real concern. If you can capture enough solar power during the day to offset your energy bill to zero or near zero, that's good enough, but my concerns are a little more esoteric. That said, for either method, density hasn't really played a factor beyond local storage into battery banks - which is normal enough, but a very different concern.

I've heard it argued that depending on the kind and quantity of vegetation in the valley being flooded, the net methane release from so much rotting plant matter may upend the whole carbon balance of the project.

That is not to say that all dams do this, but that consideration is necessary and may require modifying or rejecting certain proposals.

I've looked into this and in the states you have to go through rigorous wildlife committee approvals, indian reservation approvals (?), have surveys done, blah blah blah. In the end if you do this on your own land you still have to sell excess power back to the grid. Kind of sucks because whether you like it or not you have to work with energy companies and the government.

That will not produce anywhere close to the claimed power. 50-100W output is more likely, as under load the turbine would slow down reducing output voltage. Measuring no load voltage and claiming some output power based on that is bogus.

Good points. Note that you could make the same comparison with offshore wind farms, which have similar nameplate capacities at much lower cost per watt, run at about 60% of nameplate over time, and are, unlike nuclear reactors, actually being deployed now and in the near future.

Alas that still doesn't solve intermittency. Even offshore is intermittent. 60% is very high, all the figures I saw where closer to 25%.

Also, nuclear reactors are deployed (Taishan 1 & 2, Hinkley Point, Flamanville...).

It is true, however, that nuclear has a glass ceiling. IMHO for the wrong reasons.

unlike solar, geographic diversity in wind goes a long way toward addressing intermittency. anyone who's ever build a server cluster or a DR plan knows the solution to higher availability is to just leave some spare capacity on the table. when wind costs 1/3rd of nuclear, and has half the capacity factor, well the math is not hard.

nuclear reactors are mainframes. gas plants are ibm/hp/sun. on-shore and off-shore wind are windows and linux on intel. solar is cell phones.

we never got rid of mainframes. they are still built and sold today. but no amount of arguing about their technical superiority in the 80s would have put you on the right side of that bet.

> geographic diversity in wind goes a long way toward addressing intermittency

This is unfortunately not true. Taking the whole Europe, either the wind blows everywhere, or it doesn't [1].

1. https://www.vive-le-nucleaire-heureux.com/images/Textes-blog...

I'm pro wind and solar, but also believe that nuclear could and should be part of the mix as well. To extend your mainframe analogy, nuclear should be whitebox PCs.

Make the plants smaller, cheaper, modular, and designed for easier maintenance and disposal.

Thank you for the correction and the "correction". When I Google, the top 3 results all show that:

1. 60% is too high for current turbines; 45% is about what recently installed turbines do. 2. Only old (and outmoded) turbines are anything like 25%. 3. The newest 12MW turbines should achieve 55-60%, as Hywind did for the (windy) winter months. Since future deployments are the topic here, that's the relevant number. Call it 55%, and say I was exaggerating by 10%.

I'm glad that ~10GW of nuclear is coming online, albeit at high LCOE. We don't know how to accelerate deployment. We do know how to accelerate the wind deployment that is already at higher volume. The small-modern nuclear camp is hoping to reach 10GW a year a decade from now at higher-than-wind LCOE. And I hope they succeed! But that is not a reason to talk down the wind and solar-plus storage wave happening right now.

Nuclear electricity is good. I wish we had a lot more of it. Nuclear advocates spend way too much time bashing variable renewables, including with trivially-Googleable misinformation such as your "25%", and not enough tackling the horrible political economy of nuclear. Safe micro-nuclear plants are an excellent start on the "economy" side of "political economy." Now y'all need to build a political coalition—and pro-variable-renewable peeps such as myself must be part of your core coalition if you are going to get anywhere. So start treating us as allies.

> Eco Wave Power now intends to scale up the technology by installing more units to provide 5 MW of electricity.

The 100kW station was a proof of concept. Like, obviously 5MW is still a long was from 1GW, but it does change the math from 10,000x to 200x, which feels a bit more reasonable.

5 MW is the total sum of rated power output of all stations. If we take into account the actual power output, that's actually much lower (from 1.5x to 5-10x).

See loads for wind and solar.

The first nuclear power plant, Obninsk, provided all of 5MW. Proofs of concept are usually pretty small. That said, wave and tidal power are historically problematic, but it's interesting progress.

Centralization is another aspect. Small leaf generation capacity close to use is more resilient and far less individually costly that large central reactors that concentrate control and risk.

Centralization is not a bad thing, because energy usage is mutualized.

Taking France as an example, the total installed capacity is 400GW, but the actual power consumption is between 60GW and 110GW.

So you need some form of mutualization, unfortunately, in order not to provision 400GW but only use 100GW.

The point is risk mitigation. It seems to me we should expect an increasingly turbulent natural environment that will be driving an increasingly turbulent political environment.

If you don't remember the 2003 blackout, perhaps failure modes aren't forefront in your mind, but they merit consideration. Designing for 2050 while assuming the world looks like 1950 is a bad idea.

Nuclear energy in an violent political climate or war is indeed something to consider.

Centralized doesn't mean monolithic. Centralized under one entity, but distributed in nature.

France has 58 nuclear reactors (one of the greatest and fastest decarbonisation in history [1]). They are "centralized" in the sense that they are operated by a single entity, but effectively distributed. And indeed they are not all running at the same time (reloading fuel, maintenance) etc...

1. https://twitter.com/laydgeur/status/1232667445246222338

One of these stations will not give me cancer while a typical nuclear reactor very much might. The laws of physics sure are harsh. Such as there is no safe level of radiation, radiation releases usually happen around fission reactors and any fission nuclear reactor will make life more dangerous for people around it.

Furthermore, it should be noted that new sources of energy usually start out as being small and expensive and inefficient. After some time and investment the more promising ones can prove to be plentiful and efficient.

Solar and wind were once considered to be esoteric and expensive. Now they are both vastly cheaper than nuclear and even somewhat cheaper than fossil fuel alternatives.

> One of these stations will not give me cancer while a typical nuclear reactor very much might. The laws of physics sure are harsh. Such as there is no safe level of radiation, radiation releases usually happen around fission reactors and any fission nuclear reactor will make life more dangerous for people around it.

Is this the real truth as to why nuclear hasn't caught on?

While the OP's statement is factually untrue, fear of nuclear is one of the biggest reason indeed.

IECC and UNSCEAR disagree with you.

> The laws of physics sure are harsh. Such as there is no safe level of radiation

This is debatable[1]. I'm not saying you're wrong, but this isn't settled science and there are some interesting experiments planned to help us better understand whether or not there is radiation hormesis. Given that we and all of our ancestors have lived with some level of radon exposure, it could be an adaptive trait that has been selected for.

[1] https://en.wikipedia.org/wiki/Radiation_hormesis

If there is no safe levels of radiations, then I hope OP doesn't get near other people because a human body radiates 5000-7000 Bq.

Hopefully he lives in a lead bunker because the earth telluric a background radiation ranges from 1mSv/year to 35 mSv/year.

I hope he doesn't take the plane, too.

And so on...

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