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Comment by natch | Hacker News Reader

Smaller, safer, and just as friendly to centralized top-down control by governments, utilities, and mega corporations. Unlike solar which can be controlled by yourself on your own property.

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While rooftop solar does allow you to go completely off-grid, if you still want to have a grid around, it will have to be centralized. An underappreciated aspect of power grids is just how much advanced control is required to keep the entire thing stable and functioning, think armies-of-PhD's-difficult. When grids get too small, or don't have sufficient control (either knobs, or software/people turning the knobs), the results are frequent blackouts. Interestingly, the risk begins increasing again as your grid gets too large: you have too many knobs to reasonably control centrally, and it certainly won't work without synchronized control. As a case study, see how China is breaking up some of their huge electricity grids (in to still-large ~1000mile or so regions), as maintaining reliability and preventing faults from propagating across the country became too difficult.

Yes I agree, and thought I said nothing to imply that being on the grid is not useful, but maybe I could have made this more clear.

Na, you were fine, sorry if I came across adversarial. I just thought commenting here was an okay place to put my rant.

You don't need armies of PhDs to operate a nuclear reactor, just very strict procedures, trained personnel and military discipline.

I agree that a complex grid complicates things quite a lot. Just don't depend on the grid for anything, especially cooling a reactor after SCRAM.

> As a case study, see how China is breaking up some of their huge electricity grids (in to still-large ~1000mile or so regions), as maintaining reliability and preventing faults from propagating across the country became too difficult.

Have a source on this? IEEE says they're planning to merge the regional grids into a megagrid: https://spectrum.ieee.org/energy/the-smarter-grid/chinas-amb...

> While rooftop solar does allow you to go completely off-grid, if you still want to have a grid around

Why would you want to have a grid around?

Friends have been entirely off-grid in the Yukon for over 7 years now. They have a large, modern house with every convenience. Last time they tried to switch house insurance the insurance company didn't want to give them a policy because they don't have "stable" power supply.

My buddy replied by asking how many power outages the insurance person had been through in Whitehorse in 7 years (easily a few a year)... his off-grid setup has never had a single outage in 7 years.

So who has the "unstable" power supply?

>Why would you want to have a grid around?

Because vast majority of the world are and will be living in Mega Cities.

It’s not an either / or. Nuclear makes a good backfill for the variable output of solar and wind.

Sort of agree. But unfortunately as a taxpayer or ratepayer you still end up sharing the cost of centralized boondoggles when they happen. Less so with decentralized elements of the system.

Nuclear is not that expensive over its entire lifetime though, the biggest issue (aside from safety and security concerns) is the huge up-front investment. In theory SMRs improve that significantly by providing smaller self-contained units which are easier to reclaim (unlike a traditional power plant site which can't really be reused even if you decommission it).

People try to point to operating cost once the investment cost is amortized, but that's only relevant for the decision of whether to shut down an existing nuclear plant. The fully loaded cost, including the cost to build and finance the plant, is the relevant figure when deciding whether to build a new nuclear plant.

And even on operating cost, many nuclear plants in the US have failed to be cash flow positive in recent years, and have been shut down before their end of their lives. The remaining reactor at Three Mile Island had not made an operating profit in six years before it was ended.

I think there may be some clever accounting going on if it’s claimed to not be that expensive. Example, the carbon offsets that should be required for for the concrete typically used in a large plant are never spoken of. And cleanup and disaster recovery costs are probably tucked away somewhere else or even far off the balance sheet, out of sight.

They used to say nuclear energy would be “too cheap to meter” and if that can come to pass (safely) I’m all for it but the accounting has to be done honestly.

Does it? I'm trying to think what the poison transients would be like on a core of that shape and size... In any case, I know that large commercial plants have transients that all but preclude the use case you're suggesting, since the daily periodicity of of the demand variability is much shorter than the poison transients.

Nuclear makes a terrible backup to wind/solar. They aren't compatible. The problem is nuclear needs to generate most of the time to make economic sense. That's not a backup source, that's a baseload source.

Sounds like we need this: https://en.wikipedia.org/wiki/ELENA_reactor

Or these: https://www.nasa.gov/directorates/spacetech/kilopower

But one has to be wary about the gap between reality and institutional or governmental propaganda (I’m looking at Russia but it happens in any country).

With great power comes great responsibility (to clean up the mess). One can have rooftop solar and live off the grid anyway, so what's the worry? It's not like the average Joe is qualified to operate a nuclear reactor in his garage, but we're getting closer with SMRs and micro reactors.

You need a pretty big property to be self sufficient, or a very reduced lifestyle. The typical American consumes about 10kW of primary energy at all times, on average. That's hundreds of square meters of panels.

And a small turbine and a wood furnace for heating.

No, just good insulation and a heat-exchanging ventilation system. See Amory Lovins's banana trees in Snowmass, Colorado.[0]

[0]https://mountaintownnews.net/2017/11/21/amory-lovinss-long-s...

That's super interesting for a 40 years old home, around here homes from that time sometimes don't even have double-glazed windows. It's too bad that there are no details being provided, but other articles[0] give more information and aside from the house being covered in solar panels it doesn't look too alien (save for the very bendy walls) at least until you find out the walls are 40cm thick and the greenhouse is absolutely integral to the concept.

I really like that the greenhouse uses permanent water fixtures (a waterfall, brook and pond) for both ambience and humidity control, I've been thinking about this sort of things and how to heat responsibly: mixed wood / pellet furnace was about my best idea, and apparently the Lovinses still have a backup wood-burning stove though their 2009 "v2" renovations allowed them to get rid of the gas-fired stove and heater.

One of the things which I find more interesting is how diametrically opposite they went for one of the directions: opening up the house using efficient glass panes, where I was thinking more towards burying it, in a more extreme version of turf houses. But that makes sense if you want to produce your own electricity using solar panels, you couldn't maintain a proper turf cover then.

[0] https://grist.org/climate-energy/amory-lovins-high-tech-home...

Your math is incorrect. 10k at all times per person x 2.6 people per household x 24 hours x 365 days would be 228k kwh per year per household.

In fact it's 10-11k kwh per anum. Many developed nations use 5-7k and don't live greatly reduced lifestyles.

http://shrinkthatfootprint.com/average-household-electricity...

It's hard to calculate the exact size due to multiple factors but the following source says a 2 kw system can use as little as 150 Sq feet. In some places you could generate enough to power your house in 3 hours or an American house in 6.

Presumably solar and power storage will keep getting cheaper. https://us.sunpower.com/blog/2019/07/16/how-much-solar-power...

I'm not talking about electricity alone, but about primary power consumption. That includes heat and fuel for your car, and also all the energy consumed by domestic industry. It's about 2.5155×10^13 kWh, or 81,800 kWh per person (in 2009)[1]. You're of course right that just electricity is much easier.

[1] https://en.wikipedia.org/wiki/Energy_in_the_United_States#Pr...

It's always a red flag when "primary" energy comes up. Something like 3/4s of that primary energy will be wasted as heat while being converted into useful energy, and so renewables have a 4x advantage just by their very nature of directly making electricity.

(They also have a 4x advantage even if generating heat is the actual purpose, but for different reasons.)

Sure, if you take that into account you still need several kW of average energy production. Unless you live in a very sunny area that's a lot of panels. Panels in Germany for example get about 10-15% of their peak rating if you average over the year.

Hah, no way. A little back of the envelope calculation shows that if that claim was correct, my electric bill would be 10 times higher than it actually is ($25 per person in reality, versus $250 per person in your world). Nope.

https://news.ycombinator.com/item?id=21788298

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