Germany produces the power of 20 "nuke plants" through SOLAR GRIDS

[Clarke]

Those 2008 sq miles aren't necessarily contiguous, and some of it may actually be roofs of peoples' houses, but according to the linked article, it is there somewhere.

[Niri Te]

That isn't as bad as taking up farmland or Forest, but it still is not a good thing.

[Human No More]

Yep. Placing a panel on everyone's roof doesn't provide for all their power needs anyway.

I know someone who is getting them, and they worked out that while they will make a bit of money from feed-in tariffs at certain points of the day, for the most part it will simply reduce what they draw from the grid - that is, they will still need power actually generated somewhere centralised, and the money gained from the excess will only be enough to act as a discount on the bill, they will still be paying. This is for a fairly large, modern (well-insulated) house that gets direct sunlight on its roof for most of the day.

Decentralising elements is a good idea, but it's never a replacement for real infrastructure as it's never efficient enough. Even if every building had them, so excess generation / excess load could be balanced between them, it would be a negative sum. That's why if people want to fit expensive panels, it's fine, especially if any unused generation capacity is returned, but why building state-sized arrays is less sensible compared to nuclear/gas generation to cover supply dips/demand peaks.

[Niri Te]

I agree with you, HNM, it is way too much land to be eaten up for the panels.
Niri Te

[Clarke]

Therefore, nuclear.

[Niri Te]

Clarke, I get the feeling that you work somewhere in the nuclear power industry.
Niri Te

[auroraglacialis]

Originally Posted by Niri Te

Could some of our German members comment, and give updates on this great news??
Niri Te

Just saw this, so I reply.

I think there is a lot of (deliberate) confusion in Germany and elsewhere about Germany and the "renewable energy plan". Therefore it is a bit hard to say what is missing from the picture, but I'll try.

This one is in the news yesterday and also in TV discussions:

Originally Posted by Niri Te

German Solar Subsidies to Remain High with Consumers Paying the Price - SPIEGEL ONLINE

So while it is true that Germany has already a high potential to supply renewable energy, of course the problems persist that it is expensive and it cannot easily be stored. The problem with expenses is what is in the news this week, but the main focus is not as much as to if it can be done, but rather it is who pays for it. Right now, private households seem to be complaining a lot about this, because some parts of industry are excempt from paying the fee that was put on electricity to pay for the switch to renewables. It seems to work that way, that every bit of electricity that is used has a fee on it that goes into a fund which is used to subsidize renewable energy projects. Now that sounds good at first - after all switching from cheap and dirty coal to solar power will obviously cost some money (the same is true for developing and building next generation nuclear power BTW). What makes people angry now is, that the largest industrial consumers of energy are excempt from that payment, leaving small businesses and private households to pay for multiple their share. This is reasoned by saying that otherwise that industry would leave the country and people would have no more jobs. (Seems like globalization keeps biting us in the behind).
The problem of intermittency is also not something that will be fixed immediately. The strategy of the engineers planning this consists of 3 points - one is a better grid to distribute power across Europe, so that North sea wind power can fill in the gaps in solar power generation in BAvaria on a cloudy day and vice versa - the larger that grid, the more likely it is that somewhere in Europe either the wind will blow or the sun will shine. The next is to build storage facilities - either pressurized underground caves (old gas reservoirs) or artificial lakes. In both cases large amounts of energy are stored (at a loss of course) for peak demands. The third is to actually build more natural gas power plants. These can eventually also be fueled with biogas. The advantage of these is that they can supply peak demand but can also reduce output very fast. This is unlike coal or nuclear which can only provide a baseload and cannot adapt to fast changes in demand. However obviously there will be a lot of demand for publicly owned power plants because these will not be operating at the economic maximum (since they have to shut down whenever there is wind or sun and then they make no profit). This is where free market economy stands a bit in the way of realizing the whole idea.

Originally Posted by Isard

The only problem being that the sun doesn't always shine.
Keep the nuke plants for days its shady, and sell the excess energy to neighbors imo.

See above - nuclear power plants are the worst at providing the energy for the shady days because they take hours to move from production to shutdown and vice versa - plus every such operation is a bit of a risk and it costs almost as much to keep them running at full power as to keep them running at half power. Nuclear is best at providing a large baseload. It is like an engine that can only run at full speed - great for long distances but useless without a technology that can serve when less than full speed is needed.

Originally Posted by Clarke

Those 2008 sq miles aren't necessarily contiguous, and some of it may actually be roofs of peoples' houses,

Indeed I think covering all houses and factories may be a good idea and in Bavaria there are massive amounts of solar panels on rooftops already. However it is also economic to turn agricultural land into solar farms which is not the best idea. To try and power all of Germany exclusively by solar power would not work. It will have to be an energy mix.

Originally Posted by Niri Te

Clarke, I get the feeling that you work somewhere in the nuclear power industry.
Niri Te

Yes, I get that impression as well.

BTW - regarding people being afraid of that little bit of radiation. Yesterday they had a piece on TV about butterflies in Japan. It seems that in the greater area around ****ushima, something like 2/3 of all butterflies have deformities - extra legs, deformed tentacles, missing eyes, discolored wings. This is so sad. And the scientists in that clip on the news were basically just worried if this also applies to humans who are living in the same area and if they should rather leave. Of course this is a concern (geez - imagine to raise kids in an area that is contaminated enough to deform butterlies massively and the kids bring them home from the park and ask you why they look like that). But other than human beings will not be able to just leave the area. the butterflies will not just go somewhere else. They will have to live there with the radiation for the next hundreds or thousands of years.
Even if one could build safer nuclear plants, no one can build them perfect enough to never fail like that again. By the way - France, the "great nuclear nation" that is enthusiastic about nuclear, spends lots of money in that technology and has more than ten reactors built between 1990 and now (less than 20 year old ones) - it failed miserably the european "stress test" for nuclear reactors that was conducted after Fukushima. And that "stress test" was a joke anyways because it basically only covered basic safety measurements plus flooding and earthquakes. Something like a deliberate attack, a planecrash and some other scenarios were not even considered.

[Niri Te]

Thank you auroraglacialis, much thought went into your reply, and with you studying for your Phd, no less. The same "the companies will move to China" excuse is used HERE in America as well. The Government could STOP that trash by saying, "FINE, go ahead and MOVE to China, and ALL of your imports to this Country will be charged a 100 percent tariff, paid by the the company BEFORE the goods are allowed in the country, with NO refund if you move them back out of Country".

[Clarke]

Originally Posted by auroraglacialis

The problem of intermittency is also not something that will be fixed immediately. The strategy of the engineers planning this consists of 3 points - one is a better grid to distribute power across Europe, so that North sea wind power can fill in the gaps in solar power generation in BAvaria on a cloudy day and vice versa - the larger that grid, the more likely it is that somewhere in Europe either the wind will blow or the sun will shine.

This is a very good idea, but relying on it isn't - we don't have unobtanium, so powering France in the night-time off the North Sea will cause massive resistive losses. Moving electricity is not free - in fact, IIRC, it may have exponential cost - and so treating Europe, or the US, or wherever as a single unit may not be useful.

The next is to build storage facilities - either pressurized underground caves (old gas reservoirs) or artificial lakes. In both cases large amounts of energy are stored (at a loss of course) for peak demands.

In a all- or mostly-nuclear grid, this is only a problem if the peaks are both not predictable ahead of time and happen faster than the reactor can be adjusted to cope. Even in those cases, the storage facilities can be smaller and store less power at any given time.

The third is to actually build more natural gas power plants. These can eventually also be fueled with biogas.

Considering natural gas' track record, this doesn't sound like a good idea. Calculating backwards from those statistics, (using this value for world energy consumption) says that natural gas lead to 17,000 deaths a year.

However obviously there will be a lot of demand for publicly owned power plants because these will not be operating at the economic maximum (since they have to shut down whenever there is wind or sun and then they make no profit). This is where free market economy stands a bit in the way of realizing the whole idea.

Well, if you have the capacity in gas to power everything, that's what you would do unless the renewables were cheaper. In which case, it'd be more profitable to shut down the gas plants.

(If it's not profitable at all, then you have bigger problems. )

See above - nuclear power plants are the worst at providing the energy for the shady days because they take hours to move from production to shutdown and vice versa

If you have to do that, I think ur doin' it wrong, considering AFAIK energy consumption doesn't vary that much. If you have any stats on this, I'd like to see them.

Nuclear is best at providing a large baseload. It is like an engine that can only run at full speed - great for long distances but useless without a technology that can serve when less than full speed is needed.

Well, some designs can vary output, so you can have a system of nuclear + storage, and so cover a varying power output using that.

Indeed I think covering all houses and factories may be a good idea and in Bavaria there are massive amounts of solar panels on rooftops already. However it is also economic to turn agricultural land into solar farms which is not the best idea. To try and power all of Germany exclusively by solar power would not work. It will have to be an energy mix.

Wind's footprint is even worse. You will be required to have some sort of fuel-based power generation going on, and nuclear is so far and above all other methods in efficiency that it'd almost be foolish to use anything else.

Yes, I get that impression as well.

I don't, unfortunately. I simply know that nuclear is a lot more efficient than every other option. For instance, here's an edited chart to show how large power plants you'd need to power various places. (The "D" is presumably for Germany.) Solar farms are in red, nuclear in blue.

Even if one could build safer nuclear plants, no one can build them perfect enough to never fail like that again.

As an example, pebble bed reactors are built around a negative feedback loop - they must be actively cooled to continue working. In the case of a Fukishima-like accident, they heat up until they reach an equilibrium temperature, and then remain there until someone starts feeding coolant again. That equilibrium is part of the design, so you know it ahead of time. There is even a minor advantage, in the case of flooding specifically: the water would act as a very inefficient coolant, thus slightly decreasing the equilibrium temperature.

[Human No More]

One small point - the baseload doesn't vary much, but what does happen are short spikes of the kind caused when adverts come on on TV so people go and put the kettle on (seriously; energy grid control centres monitor TV schedules). That's what pumped storage is for because no conventional generation source is fast enough to react to them, with the possible exception of production-grade fusion implementations, which are still a way off.

[auroraglacialis]

Originally Posted by Clarke

This is a very good idea, but relying on it isn't - we don't have unobtanium, so powering France in the night-time off the North Sea will cause massive resistive losses.

They are not low but they are also not that massive if proper technology is used. A loss of 14% over 5000 km is IMO quite acceptable (source). Especially as this is not something that is permanently the case if there are efforts to locally improve the energy mix to reduce the need for imports.

In a all- or mostly-nuclear grid, this is only a problem if the peaks are both not predictable ahead of time and happen faster than the reactor can be adjusted to cope

small peaks are not predictable at all and larger shifts are predictable, but still nuclear plants are not used to adjust to them. In fact they are presently normally running at high capacity continuously while coal fired plants do the predictable hour-by-hour adjustments and oil, gas and storage plants do the smallscale spikes.

Increasing the use of less predictable energy sources would require a greater adaptability of the power net. thus nuclear power is not a good bridge technology in combination with renewables, because they do not work together. If renewables are to be buit, one needs a complimentary increase in the fast reaction plants - gas, water storage etc. If one desires instead (and this is exclusive of each other) a nuclear option, basically nuclear can replace existing slow coal plants, thus little change to the energy system would have to be made - nuclear would then also be adjusted to the hour-by hour demand and smaller fluctuations would still be covered by natural gas and water storage.

Considering natural gas' track record, this doesn't sound like a good idea.

I dont know what you calculated there to get to 17000 deaths (powering the whole world exclusively by natural gas?), but the idea of using it as a complimentary to renewables is, to use it only if there are peak demands and/or lack of supply in wind+solar. Also the idea is to eventually use biogas from non-food materials (animal waste, agricultural residues) to power them. This is done quite economically already in some agriculturally dominated counties here in Bavaria.

Well, if you have the capacity in gas to power everything, that's what you would do unless the renewables were cheaper. In which case, it'd be more profitable to shut down the gas plants.

Thats a challenge of course. The market would be so, that in most cases renewables are going to be cheaper if the sun shines and the wind blows, but then there will be shorter times in which gas plants are much cheaper when there is a peak demand. Essentially, these plants would have to make a profit by running only a few hours a week. In a purely free market economy, this would then mean that during peak demands, these power stations would be able to charge very high prices for their precious power and they would have to do this to be economic. In a more state-regulated economy like in Germany, it may be possible to run them at a loss as a service. Like roads, who are a big loss to the state every year, but provide the infrastructure needed to allow commercial transportation. These peak demand gas stations could serve a similar function and provide the "safety net" to allow renewable energy companies to function.

If you have to do that, I think ur doin' it wrong, considering AFAIK energy consumption doesn't vary that much. If you have any stats on this, I'd like to see them.

Here is one from wiki: Datei:Lastprofil VDEW Winter mit Kraftwerkseinsatz schematisch.jpg ranging over the course of a day between 20% and 100% within a few hours. At one place, the demand doubles within an hour (red line @ 8:00-9:00)! The dark brown area is by the way brown coal plus nuclear power, which is barely adjusted at all. This also does not include the small scale fluctuations illustrated here:

Well, some designs can vary output, so you can have a system of nuclear + storage, and so cover a varying power output using that.

This pebble bed reactor design technology is not proven to work properly. The only one I know that was run for a longer time was eventually shut down and they found afterwards that there were massive amounts of these pebbles ground to bits in the vessel.

For instance, here's an edited chart to show how large power plants you'd need to power various places. (The "D" is presumably for Germany.) Solar farms are in red, nuclear in blue.

This is quite stupid propaganda. What does that blue dot incorporate? Just reactor buildings? What about the open pit mines to get the Uranium and the mine tailings? What about the dead zone around Chernobyl and Fukushima? And who says that area is the defining factor in determining "efficiency"? It is an arbitrary choice to make. There are other parameters that one can choose for a comparison and that will not let nuclear look like a good option. Radiation for example. Coal and Nuclear are really ****ty there compared to solarthermal for example. Or danger of weapons proliferation - show me a case where solar panels specifically are used to make bombs. With nuclear power, the danger is large enough to have us waiting for the impeding invasion of Iran by Israel for years now.

As an example, pebble bed reactors are built around a negative feedback loop

Geez - pebble bed reactors are even called unsafe by members of the nuclear engineering community. The pebbles break and are releasing contents, the reactor vessel can have cracks in whcih the pebbles get caught up, intrusion of water into the reactor can lead to supercriticality of the reactor and lead to explosions. This is just the list of what already has happened or was almost happening in the two reactors in Germany.

Here is a citation: "W.Braun,W.Bürkle: Can inherent safety replace active and passive safety systems ? Kerntechnik 51 (1987) 169 ff"

And here is wikipedia on the two reactors of that type in Germany: Pebble bed reactor - Wikipedia, the free encyclopedia

And here are two more citations on the troubles that such types of reactors can have that would lead up to a "Chernobyl type accident"!
"J.Szabo et al.: Reactivity effects of water ingress in HTGRs - a review. In: Technical committee on reactivity transient accidents. Proc. of the first technical committee meeting organized by the IAEA and held in Vienna, 17.-20.11.1987. Document IAEA-TC-610
J.Szabo et al., Nuclear safety implications of water ingress accidents in HTGRs, Nuclear Society of Israel, Transactions 1987, IV-13 ff"

This technology is dead for now. I dont want to exclude that there are technologies that are safer than the present nuclear power generation, but to pull out old failed reactor designs and promote them as next generation solutions is more desperate than progressive.