Poll Nuclear Power

[Urwumpe]

12 m height is much too low for steady winds especially if you are in pretty populated places. about 10 m more and you should be above the turbulence layer.

But: While not every place is suitable for placing wind turbines, 8% of Germany's surface area for example would be perfectly suitable including distance to settlements and other soft factors, 2% of the surface area would be needed for wind turbines to cover the power consumption of Germany (without good energy storage technology). While 2% doesn't sound that much, it is a lot of area effectively.

---------- Post added at 11:59 PM ---------- Previous post was at 11:57 PM ----------

wind energy captured at a turbine is unable to be used downstream.

Downstream ends after about 3 rotor diameters.

 

[T.Neo]

There's also a hidden cost to solar, wind and hydro. What effects will they have on the environment? Energy isn't free, wind energy captured at a turbine is unable to be used downstream. Solar shades areas and prevents the sun from heating the Earth, and even at 40% efficiency, I doubt that 60% is doing the job it was originally supposed to. Hydro disrupts the natural course of streams and rivers, with tidal preventing the natural tidal energy from um...doing whatever tidal energy does.

Solar panels should have a low albedo, and while only 40%, say, of the energy hitting it, is being converted to electricity, a good deal of the 60% that isn't, is being absorbed by the panel and then being reflected, thus heating the panel, and thus the planet.

In fact, in comparison to your general natural high-albedo arid region, solar collectors would actually increase the amount of energy coming into the system.

Considering so many other variations though, that bit of area probably wouldn't be that influential on a global scale.

If you increase your efficiency, you need less area for a given amount of power, and this issue becomes less apparent.

Hydro disrupts the natural course of streams and rivers, with tidal preventing the natural tidal energy from um...doing whatever tidal energy does.

I only raise this issue in regard to tidal power, because I've heard that Earth's tidal energy budget is only 3 terawatts. The current power production of humanity is maybe, 16 terawatts? If a fourth of that is electrical, then tidal energy alone will not be able to satisfy it. Of course, if you sapped up all those 3 terawatts of energy, then there wouldn't be any tides anymore. Which has the benefit of essentially stopping the orbital expansion of the Moon, but it could have far more immediate- and problematic- effects. It'd be extremely disruptive.

I do think this image is worth posting again, just for fun if anything else:

The energy is all there, more than we could ever sensibly use. The key is just finding a way to use it productively.

Nuclear however, has a tiny physical footprint per watt of energy produced, and short of Chernobylling or even Three Mile Islanding has comparatively minimal impact on Earth. Yea, it warms up some of the local water a bit, but compared to disrupting a whole river, or whole stretch of coastline (tides), or disrupting the wind, I'd call that a relatively minor disturbance.

It also produces radioactive waste, and as safe compared to CO2 emissions that might be, and indeed as safe in general as it might be, it's still there.

Renewable energy is the ideal energy source. Even if it is not a solution to our immediate problems, it is most definitely something we need to be working towards using.

But: While not every place is suitable for placing wind turbines, 8% of Germany's surface area for example would be perfectly suitable including distance to settlements and other soft factors, 2% of the surface area would be needed for wind turbines to cover the power consumption of Germany (without good energy storage technology). While 2% doesn't sound that much, it is a lot of area effectively.

2% of Germany's area is what, 7100, 7200 km^2? That's more area than Brunei...

 

[Zatnikitelman]

Downstream ends after about 3 rotor diameters.

So the energy extracted by the wind is magically replaced 3 rotor diameters downstream from the turbine?
Where does this energy come from?

 

[FADEC]

The question whether nuclear power is safe or not is a little vague I think. What does "safe" mean? Nothing is safe in our lifes, except that we have to die at any one time. Cars aren't safe. Airplanes aren't safe too. There is always a chance to crash. And of course nuclear power also isn't safe, except with the significant difference (to cars and planes) that it doesn't effect individual cases but hundreds of thousands of peoples lifes, nature and animals. Harrisburg, Tschernobyl and Fukushima is proof enough how "safe" nuclear power is in the real world, aside from diffuse statistics and numbers which are intended to make its readers feel safe. How many fatal "isolated incidents" do we need yet until decision makers realise it's anything but safe, especially in highly skilled technology nations like Japan?

I'm very glad to live in a developed country which will phase-out this dangerous end-of-range technology. Bill Gates calls it an indication of wealth. He is right. And I add: it's also an indication of rationality. Nuclear power has no endless future, just like coal and oil also hasn't. T.Neo actually made a good point. There is nothing more powerful in our solar system than the sun. It's an ineffable big source of energy. It's nuclear fusion all for free. It drives the entire ecosystem on this planet and in interaction with the topography and water vapor it decides how the weather is going to look like tomorrow.

If we manage to use the sun effectively, the human race can be called smart, or at least a little smarter than before (wars won't stop though...).

Sun + wind + water is a perfect mix. It's endless power.

 

[Unstung]

Solar power is less efficient (not even close to 50% efficiency), requires much more space, and more expensive than nuclear power. In terms of power plants, environmentalists want solar and wind power, too expensive, nothing happens, and we're still running on fossil fuels. Solar power is being improved, such as in terms of efficiency (beaming down energy from space using a safe ray is my favorite idea; not only does it save land, more sunlight energy is available), but nuclear power is [ame=http://en.wikipedia.org/wiki/Generation_IV_reactor]being made safer[/ame]. These future reactors would have much safer waste lasting for far less time and have methods to prevent meltdowns, even with no power. I doubt the chance a much better power source could emerge in 50 years as I think Merkel mentioned.

 

[T.Neo]

So the energy extracted by the wind is magically replaced 3 rotor diameters downstream from the turbine?
Where does this energy come from?

The wind, of course.

It presumably blows in from outside the rotor's "shadow", as it were.

Solar power is less efficient (not even close to 50% efficiency),

Of course. But the difference is that there are petawatts of energy available, for free.

You still have to capture and distribute it, and therein lies the trick...

 

[FADEC]

Solar power is less efficient (not even close to 50% efficiency), requires much more space, and more expensive than nuclear power. In terms of power plants, environmentalists want solar and wind power, too expensive, nothing happens, and we're still running on fossil fuels. Solar power is being improved, such as in terms of efficiency (beaming down energy from space using a safe ray is my favorite idea; not only does it save land, more sunlight energy is available), but nuclear power is being made safer. These future reactors would have much safer waste lasting for far less time and have methods to prevent meltdowns, even with no power. I doubt the chance a much better power source could emerge in 50 years as I think Merkel mentioned.

Solar and wind is not the only solution. One also needs water, but also gas initially.

But let's take a look to Norway. 98% of the electricity in Norway is comming from hydroelectric power plants. They even drive their heater with electricity (not with gas or oil) which would be way too expensive in Germany. It works for 5 million people. It can also work for 50 million or 100 million or more people. In Germany we have a city (200k inhabitants) which is already independent from nuclear power.

Those arguments (safety and antipollution) calling for nuclear power are outdated and untrue anyway. Any sane person does know it these days. Safe nuclear power is and will continue to be a cloud-castle. And the nuclear waste always fades into obscurity. To rely on limited resources is not very smart anyway. Uranium also will run short. Nuclear power has no future, at least not in Germany anymore

 

[T.Neo]

It should be noted that with the right setup, there are nuclear fuels on Earth that could last for thousands or tens of thousands of years, not tens or hundreds. While they are not an infinite resource, they are sure better than oil or coal.

That said, it doesn't really remove the other factors in the discussion of nuclear power.

 

[Urwumpe]

So the energy extracted by the wind is magically replaced 3 rotor diameters downstream from the turbine?
Where does this energy come from?

if you drive behind another car, do you always have the same reduction of drag like being directly behind it, regardless how far away you are?

The wind turbines only consume a small bit of air. The wind doesn't end at 100m altitude, the mass of air that is moving is pretty huge.

 

[Tommy]

Solar and wind is not the only solution. One also needs water, but also gas initially.

But let's take a look to Norway. 98% of the electricity in Norway is comming from hydroelectric power plants. They even drive their heater with electricity (not with gas or oil) which would be way too expensive in Germany. It works for 5 million people. It can also work for 50 million or 100 million or more people. In Germany we have a city (200k inhabitants) which is already independent from nuclear power.

Those arguments (safety and antipollution) calling for nuclear power are outdated and untrue anyway. Any sane person does know it these days. Safe nuclear power is and will continue to be a cloud-castle. And the nuclear waste always fades into obscurity. To rely on limited resources is not very smart anyway. Uranium also will run short. Nuclear power has no future, at least not in Germany anymore

To be fair, Norway's geography is ideal for hydro power - most countries couldn't meet their energy needs using only hydro, at least without building more and bigger dams. That would cause lots of problems.

That said, there ARE other green sources besides hydro.

 

[Urwumpe]

To be fair, Norway's geography is ideal for hydro power - most countries couldn't meet their energy needs using only hydro, at least without building more and bigger dams. That would cause lots of problems.

That said, there ARE other green sources besides hydro.

You should also add, that while regenerative power looks bad at first glance because many sources vary over day and year, if you have enough different sources over a pretty huge area, you always have places with good energy available at a time.

It just requires first of all much better power grids as we have today, most are lost in the 1950s.

 

[Unstung]

Solar and wind is not the only solution. One also needs water, but also gas initially.

But let's take a look to Norway. 98% of the electricity in Norway is comming from hydroelectric power plants. They even drive their heater with electricity (not with gas or oil) which would be way too expensive in Germany. It works for 5 million people. It can also work for 50 million or 100 million or more people. In Germany we have a city (200k inhabitants) which is already independent from nuclear power.

Those arguments (safety and antipollution) calling for nuclear power are outdated and untrue anyway. Any sane person does know it these days. Safe nuclear power is and will continue to be a cloud-castle. And the nuclear waste always fades into obscurity. To rely on limited resources is not very smart anyway. Uranium also will run short. Nuclear power has no future, at least not in Germany anymore

Norway is a tiny country that doesn't produce as much hydroelectric power as these other countries: China, Canada, Brazil, United States, Russia. Germany would need to make some major changes to rely on hydroelectric power. I doubt the country has enough resources for that.

As I mentioned, new reactors (specifically Generation IV; Generation III+ to some degree) will use fuel more effectively and be safer. A possibility for Generation IV reactors is to use liquid thorium fuel (MSR reactors). It's less radioactive, much more difficult to have a meltdown, more efficient, lasts for a fraction of the time of uranium -- a few hundred years compared to thousands (which I mentioned more vaguely earlier). Thorium is hundreds of times more efficient than uranium. Its reserves are estimated to be abundant in nature, more so than uranium. Much smaller and more numerous plants can be built, too.

 

[Urwumpe]

Thorium is hundreds of times more efficient than uranium. Its reserves are estimated to be abundant in nature, more so than uranium. Much smaller and more numerous plants can be built, too.

Not more effective, Thorium has the advantage of being the cheaper fuel since you can use it without much effort.

Also: Germany did not enjoy their AVR for long, which was a Thorium reactor. It was even the highest contaminated ruin in the world until one year ago.

[ame="http://en.wikipedia.org/wiki/AVR_reactor"]AVR reactor - Wikipedia, the free encyclopedia[/ame]

All the reactor types you mentioned, are only existing on the paper. The most recent generation that was ever build had been Generation III, and this had been the pretty well-designed, but ineffective CANDU designs (they are even less suitable for district heating as other nuclear reactor designs).

And unbuilt stuff is ALWAYS better, cheaper and safer as all the built stuff. ALWAYS. Even if you have experiences that should be a warning about such claims.

 

[FADEC]

As I said: Sun + wind + water. Water alone won't make it just as the other sources alone. But aside from that, Norway is able to also power German cities if there was a sea cable and better power lines. For now it is basically legislation which prevents it.

That the world only works based on nuclear power is an old fable. Germany is a developed country, not as big as China but also not small. We currently have 22% nuclear power. And we could have 0% already this decade, if there wasn't the atomic lobby and more willpower. Germany exports even more electricity than France whilst they have 40 more nuclear power plants. We live in excess of electricity and the energy giants rub one's hands.

The world can be powered without nuclear power plants for sure. Nuclear power just is the easy way, but risky, and it's spitting dangerous waste which nobody wants to have below the own property.

I'm ready to pay for a better and cleaner future.

 

[Sky Captain]

12 m height is much too low for steady winds especially if you are in pretty populated places. about 10 m more and you should be above the turbulence layer.

Yeah, only problem is a 20 + meter mast in built up area could do a lot of damage if there is a failure and it falls 12 m was highest I could safely make without endangaring neighbouring property too much. Then my turbine also once threw a piece of a blade during a storm, luckily it hit only ground. Howewer accident like that could easily cause serious injury or even death if someone happened to be at wrong time in a wrong place. After that event I dismantled the turbine because my wind power experiments were just not worth the possibility that someone could get seriously injured or killed.

 

[Zatnikitelman]

if you drive behind another car, do you always have the same reduction of drag like being directly behind it, regardless how far away you are?

The wind turbines only consume a small bit of air. The wind doesn't end at 100m altitude, the mass of air that is moving is pretty huge.

My point is the old physics axiom "energy is neither created nor destroyed, merely converted from one form to another." With wind energy, you're removing the energy in one of Earth's natural and critical processes and converting it into electricity and ultimately into waste heat. What happens when our energy needs outweigh what can be supplied by wind? Pull energy off the gulf stream and turn Europe into Earth's third ice cap?
TNeo earlier did some figuring and indicated that a large solar field might actually heat the underlying ground more than the sun otherwise would. Has anyone actually figured what effects these so-called "green" technologies will have on Earth when deployed on a large scale?
Nuclear's impacts are known, and can be mitigated by proper planning and yes, management, which Chernobyl, Three Mile Island, and Fukushima did not have. It's also an existing technology that doesn't have to be further developed to the point where it's useful, unlike solar.

 

[Urwumpe]

It's also an existing technology that doesn't have to be further developed to the point where it's useful, unlike solar.

I wouldn't go so far to already claim that "nuclear power is useful". We can generate electricity and nuclear weapons with it. True. But useful is more than that. We can't use nuclear power plants for district heating, like it is possible with coal or gas power plants. That sounds like a minor problem, but means that nuclear power generates way more waste heat than electricity. They mean a HUGE drain on the local water sources, and suffer when water is not available.

Next, you can't build small nuclear power plants. This makes them useful for large power companies, but not useful at all for decentralized concepts or for small investors. You also can't operate nuclear power plants competitive, they are simply too expensive, even with taxes to subsidy them. Even compared to the enormous amounts of money that goes into making photovoltaics competitive, nuclear power is still expensive. Nuclear power plants are useful for making big companies richer and bigger - they have almost no costs, all expensive stuff is paid by the tax payer.

I would say, without nuclear power plants we would have been much further. They made us put too many eggs in one basket, and pay money for hiding problems instead of really solving them (like hiding the nuclear waste underground in the hope that it will never return)

 

[T.Neo]

Also: Germany did not enjoy their AVR for long, which was a Thorium reactor. It was even the highest contaminated ruin in the world until one year ago.

So all Thorium reactors are total deathtraps, because AVR failed?

We had a pretty silly PBR program going on recently...

I'm ready to pay for a better and cleaner future.

I love how people make things sound like a cheesy Greenpeace advert...

My point is the old physics axiom "energy is neither created nor destroyed, merely converted from one form to another." With wind energy, you're removing the energy in one of Earth's natural and critical processes and converting it into electricity and ultimately into waste heat. What happens when our energy needs outweigh what can be supplied by wind? Pull energy off the gulf stream and turn Europe into Earth's third ice cap?

Because then our energy needs would be in the hundreds and hundreds of terawatts. And I frankly do not see that happening- extrapolated growth patterns put attaining Kardashev type 1 status in around 2200. But there isn't really any reason to believe that such growth will continue- there is a sensible limit to how much power a single person can use. The developing world is becoming more... developed, with a higher standard of living, and thus a higher amount of energy usage. Once the expansion of the number of people under a high standard of living stops, power usage will also reach a sort of plateau (or more likely, correlate roughly to population growth). It could even go down as efficiency increases.

I dare say energy usage of a fully developed human civilisation with a population relatively similar to our own would be no more than 200 terawatts. Now that is a lot, compared to our 17 terawatts, but it is no hundreds-of-petawatts Type I civilisation.

TNeo earlier did some figuring and indicated that a large solar field might actually heat the underlying ground more than the sun otherwise would.

But the effect would probably be minimal, because the solar panels would cover such a small area (relatively) of the Earth's surface. When we consider the differences in albedo that come with sea ice melting, snow cover falling and melting, seasonal changes in plant life, changes due to droughts or downpours, and even differing cloud formations (probably the most sporadic and wide-ranging example).

At most, it would likely be far less of a problem compared to the ongoing addition of greenhouse gases to our atmosphere. Considering the climatic and geographical changes the Earth has undergone in the last several millions of years, it would likely have a very minimal impact.

Has anyone actually figured what effects these so-called "green" technologies will have on Earth when deployed on a large scale?

Depends on what "a large scale" is, If you're talking about soaking up 174 petawatts of solar, then yeah, it would be very bad. But a civilisation using 174 petawatts of energy would be a bad thing in and of itself.

We can't use nuclear power plants for district heating, like it is possible with coal or gas power plants. That sounds like a minor problem, but means that nuclear power generates way more waste heat than electricity. They mean a HUGE drain on the local water sources, and suffer when water is not available.

Heating isn't much of an issue in warmer countries... but the availability of water often is...

(like hiding the nuclear waste underground in the hope that it will never return)

I can't help but imagine a monster of radioactive sludge climbing out of a containment facility... :shifty:

 

[Urwumpe]

So all Thorium reactors are total deathtraps, because AVR failed?

No, but essentially the main problems with the design had also made the production-grade "THTR-300" fail and end as high-tech ruin.

http://en.wikipedia.org/wiki/THTR-300

It is not just one. of course there are also thorium reactors designs that are no pebble beds, but they solve the pebble problems by adding their own problems.

 

[Tommy]

TNeo earlier did some figuring and indicated that a large solar field might actually heat the underlying ground more than the sun otherwise would.

It would still be less waste heat than ANY nuclear plant. The largest, most recognizable structures in most nuke plants are the cooling towers.