A nuclear power plan doesn’t “use” water. It takes fresh water in and reject it later a bit warmer. That’s pretty much it.

Water usage must be one of the silliest metric used in ecology by the way. Water doesn’t magically disappear when it’s “used”. What’s important is the share of the potable water available in an area used by an activity and how much other pollutants are released in the water.

Don’t be silly, “Use“ does not imply destruction it just implies an opportunity cost. Land you use for a nuclear power plant isn’t destroyed, but you can’t put a shopping mall there until you decommission it.

Water evaporated into the atmosphere before it can be use to irrigate crops is one such cost. Nuclear therefore uses ~600 - 800 gallons per MWH not a huge amount but much larger than solar. On the other hand much larger quantities of water are discharged in such a way they an be reused down stream, that’s not what I am talking about.

> A nuclear power plan doesn’t “use” water.

Some nuclear power plants have cooling towers that evaporate large quantities of water.

So it will flow away into universe...

Water use doesn't mean destroying water. It means using some of the limited quantity of water that's available at a given time in a given place, using it for a given purpose and not some other purpose.

Water that evaporates isn't available for drinking and showers and farming.

It is - it will rain down not too far away.

So it will be available again in the future, but it's not available right now anymore.

I guess everyone here lives someplace with abundant water. When water supplies are actually limited, using water for one purpose means water isn't available for something else.

Edit:

I know nothing about European water supplies, but with a quick search I found news suggesting that is an issue even in Europe:

https://www.euronews.com/2022/08/08/nothing-left-in-the-pipe...

Where exactly in Europe are water supplies limited?

Edit for your edit: Europe definitely could do better in terms of making use of the available water - but there's no shortage of water in nature around us.

For example, the communists have damaged many rivers (made the river basins concrete etc), leading to drying of the surrounding areas. We're slowly correcting the damage. But generally speaking we have enough water. And you choose the place to build a nuclear power plant based on water availability.

Perhaps it's more of a problem in the southern states, I don't know about that. But we have an interconnected grid - we can sell electricity from one state to another (it's being done today).

Unfortunately there's water scarcity in Europe and it's only going to get worse. I'll just leave this here: https://www.eea.europa.eu/data-and-maps/figures/water-stress...

If I understand that map right... We are going to be moving from medium/severe water stress to low water stress in many central/northern areas - isn't that an improvement in water availability? Why couldn't we build the nuclear power plants primarily in the light-yellow places and transfer the electricity via the grid to the places where it's worse?

I don't understand why should we reject it altogether on the whole continent just because it's bad in Spain and Italy - OK, agreed, let's not build nuclear there maybe. The rest of the EU seems like a good place.

Most especially, Germany should stop ignoring science and make the water-rich land they got available for as much nuclear as possible. The Union needs it now more than ever, and it's not like they haven't got a hand in creating the situation.

No, in the heatwave of this summer, some French nuclear plants had to be turned off because the rivers in which the cooling water had to be released had become too warm. (Further French nuclear plants had to be turned off due to technical problems.) So France had to import much energy to meet its demand. It was mainly Germany that helped out. The same problem affected – besides Belgium, Switzerland – Germany, too, though to a lesser degree (no pun intended) because Germany is less dependent on nuclear.

https://www.businesslive.co.za/bloomberg/news/2022-08-03-fra...

https://www.powermag.com/nuclear-power-production-curtailed-...

https://www.theenergymix.com/2022/08/07/failing-french-nucle...

https://www.grs.de/en/news/built-close-water-do-increasing-d...

https://www.thelocal.de/20090630/20301/ [Rhine, too, heated up by nuclear plants]

That is a question of design and not a necessity.

> Rooftop solar is dangerous because people are putting stuff on roofs and can fall off in the process

This is very misleading. Roofing is dangerous and deaths when installing panels are blamed on solar energy.

Yet, people need to build and rebuild roofs anyways. If solar panels or shingles are installed when a house is built or refurbished accidents should not be blamed on solar energy.

Additionally, some countries (especially US) have poorly enforced work safety regulations and that can be improved. Plus, houses can be built with safe roofs i.e. flat roofs.

It’s not just installing panels homeowners will climb up to remove snow, do maintenance, etc.

On a house by house basis it’s not a significant risk, but when you start comparing it to the ~1/2 billion homes it would take to equal the worlds nuclear power plants low risks do add up.

> when you start comparing it to the ~1/2 billion homes it would take to equal the worlds nuclear power plants

...while also completely ignoring the systemic risks involving the latter.

Over grid solar?

There are some edge case advantages to rooftop solar for individual homeowners, but when everyone is connecting to the grid anyway I don’t think it’s a good idea to subsidize the more expensive option. It’s simply a waste of public funds when we can hit a larger bank for the buck both economically and environmentally.

GAF Energy in the last year came out with nailable solar shingles so the installation process is similar to a normal roof. I think that's the future because it only adds a relatively small cost to the cost of replacing a roof or new one, doesn't require any structural changes to framing (sometimes needed), and the risk of "stuff falling" is the same.

https://www.gaf.energy/timberline-solar/

Are these available to DIYers? I'm building a shed and would just as soon use these if I could. As it stands, I'm just going to overbuild the roof structure a bit and then add racked solar when I get around to it.

I don't know, but I recommend reaching out. Sounds like a cool project!

It’s better, but I still expect some fool to climb up onto their roof in the winter to remove snow etc. When you start talking 100’s of millions of homes your end up dealing with vast numbers of really dumb people.

Bold, wild claims require evidence for the rest of us to believe you. Got any?

Bold? Here’s a video of someone actually falling off their roof, but you can find plenty of videos where people are walking around their roof looking at their panels. https://www.youtube.com/watch?v=RA4HrMy9djk

Here’s an article actually recommending it for flat roofs.

Using a Shovel Method

Shoveling is the riskiest of the snow removal procedures from your roof. The reason for this is that it requires you to climb to the roof to remove the snow.

There’s risk in climbing the ladder, the shoveling itself, and the risk of damaging the roof if you step in a weak spot or hit the shovel on a delicate part of the roof.

However, it is the best especially on a flat surface/roof https://roofscour.com/how-to-remove-snow-off-roof/

There's not enough sunlight per day in the coming months in most of Europe. How's solar going to help?

To replace just a single nuclear reactor you need so many solar panels that the deaths caused by the transportation will be significant - accidents, pollution + you have to count the damaged roads that need to be replaced - again pollution and accidents. And high-voltage electricity is not exactly safe - you would need so much electrical work that there simply must be a lot of death from accidents too, on this scale we're getting into the area where it's statistics and not really something to simply prevent.

Solar panels need to be replaced after 30 years max, but most probably will be replaced much earlier because the operators want to pocket the improved efficiency of newer panels. Reactors will need maintenance but it is normal to keep them running much longer. Also, what about the human labor? To maintain such large solar array you'd need hundreds of people. A modern nuclear powerplant with 5+ reactors is maintained by few dozens of people.

I'm a huge proponent of solar energy - but on rooftops, not as a replacement of nature or nuclear power. It will never be possible to phase out fossil fuels in transport and industrial uses without nuclear power - solar just doesn't scale this much, it's perfect for individual houses but you just can't power thousands of large container ships with it, nor blast furnaces etc - and definitely not the uncountable amount of trucks and cars on roads.

How many transportation deaths are associated with ~1,000 works showing up every week to a nuclear power plant for 50+ years?

Ballpark say 1,000 people * 30 total mile daily commute * 365 days a year * 50 years round to ~1 billion miles driven over the lifetime of a power plant in the US should represent around 13 traffic fatalities. https://en.wikipedia.org/wiki/Motor_vehicle_fatality_rate_in...

Let’s call it somewhere between 5 a 25 transportation deaths per nuclear power plant, meanwhile large solar farms are often completely empty of people 90+% of the time.

>Solar panels need to be replaced after 30 years max, but most probably will be replaced much earlier because the operators want to pocket the improved efficiency of newer panels. Reactors will need maintenance but it is normal to keep them running much longer. Also, what about the human labor? To maintain such large solar array you'd need hundreds of people. A modern nuclear powerplant with 5+ reactors is maintained by few dozens of people.

To just pick at one of your "statistics": E.g. Flamanville, a reactor plant with 2 reactors (and 1 being built) employed 670 people (not a "few dozens")[1]. I would argue the solar panels are the ones needing much less people. The ones I know don't need any kind of big servicing. But in those sizes this is pure speculation from my side.

> To replace just a single nuclear reactor you need so many solar panels that the deaths caused by the transportation will be significant - accidents, pollution + you have to count the damaged roads that need to be replaced - again pollution and accidents. And high-voltage electricity is not exactly safe - you would need so much electrical work that there simply must be a lot of death from accidents too, on this scale we're getting into the area where it's statistics and not really something to simply prevent.

Electronics-wise I don't see why there is so much more (and more dangerous) work involved in wiring up solar panels compared to constructing a nuclear plant. But I don't have statistics on that. I also wanted to know if your "deaths caused by the transportation will be significant" makes any sense. For that I tried to estimate the kind of size a solar park would have be to replace a reactor plant, e.g. Flamanville. Flamanville produces 14TWh per year. I took [2] as a reference(2.14km², 117GWh) and it came out to 256km² of area to produce the same amount of energy per year with solar in the flat part of germany. Storage is missing there. This is a huge amount of space, but also nothing that will produce "significant accidents" on its own. Constructing reactors and transporting fuel rods and nuclear waste is also a huge act with tons of material involved.

> It will never be possible to phase out fossil fuels in transport and industrial uses without nuclear power - solar just doesn't scale this much, it's perfect for individual houses but you just can't power thousands of large container ships with it, nor blast furnaces etc - and definitely not the uncountable amount of trucks and cars on roads.

Maybe direct batteries are not a solution for transport and industrial uses. But green h2 would be. This then has the fortunate aspect that it can be produced anywhere and independent of the need, e.g. in the Sahara and only when the sun shines. In that way solar can replace fossil fuels and nuclear power. Regarding cars and regular power use (btw germany covers ~40% of its energy with renewables already, taking this times two or three is not an issue of "scale"), lets just take the solar example from above and try to do 150% of germany's current power needs in full solar and see where that gets us. Germany needed 624 TWh in its peak year (2007, [3]), lets be generous and say we need 1000TWh in the future. This comes down to 18300 km². Germany has an area of 358000km². So our (very generous) solar capacity would need about an area of 5%. How much is 5%? According to [4], citys and streets (etc.) sum up to 14.5%, Agriculture has about 50%, Forests 30%. Since we can "simply" put the panels on top of the first category and don't have to replace existing areas most of the time, this looks pretty feasible to me, even with exaggerated demands in napkin calculations. So maybe it does not scale well, but it does scale.

And all of this does not take into account that solar is not the only option. Power from wind is a great way to mix since wind is strong mostly when there is no/less sun.

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

[2] https://en.wikipedia.org/wiki/Templin_Solar_Park (https://de.wikipedia.org/wiki/Solarpark_Templin_%E2%80%93_Gr... has the energy statistics regarding GWh in 2017)

[3] https://www.umweltbundesamt.de/daten/energie/stromverbrauch (german, but the graph should be readable)

[4] https://www.umweltbundesamt.de/daten/flaeche-boden-land-oeko... (also german)