Global warming

[eastmen]

There is nothing bad about wind or solar, but neither are ready to be prime energy generating sources for the world. If you want clean energy, nuclear is the way to go. In a few years, that might change. However it is not today.

Solar is a smart way foward. In the winter when the sun is the weakest towards the poles people use heat which is rarely generated from electricty. Its mostly gas heat.

In the summer when the sun is the strongest people turn on air conditioning and they greatly tax the grid using all that extra power.

And solar is getting better every day . Today two start ups announced the most efficent panels yet.

 

[epicstruggle]

Solar is a smart way foward. In the winter when the sun is the weakest towards the poles people use heat which is rarely generated from electricty. Its mostly gas heat.

In the summer when the sun is the strongest people turn on air conditioning and they greatly tax the grid using all that extra power.

And solar is getting better every day . Today two start ups announced the most efficent panels yet.

I've been hearing about how solar is just around the corner for almost a decade. When it's ready for prime time it will succeed without any subsidies. We are not there yet. My point is that until that time comes move away from coal/oil power plants to nuclear. That is if AGW is a serious problem.

 

[eastmen]

I've been hearing about how solar is just around the corner for almost a decade. When it's ready for prime time it will succeed without any subsidies. We are not there yet. My point is that until that time comes move away from coal/oil power plants to nuclear. That is if AGW is a serious problem.

Is Nuclear possible without huge subsidies ?

Who pays for the waste disposal and where is it disposed of ? Who pays for the upkeep over hundreds if not thousands of years for the waste ?

At least solar is largely a one time fee and if the goverment devoted the money to it that going full nuclear would cost i'm sure prices of the tech would drop like a stone

http://www.engadget.com/2012/02/08/two-us-startups-break-solar-efficiency-records-aim-to-light-up/.

 

[epicstruggle]

Is Nuclear possible without huge subsidies ?

Who pays for the waste disposal and where is it disposed of ? Who pays for the upkeep over hundreds if not thousands of years for the waste ?

At least solar is largely a one time fee and if the goverment devoted the money to it that going full nuclear would cost i'm sure prices of the tech would drop like a stone

http://www.engadget.com/2012/02/08/two-us-startups-break-solar-efficiency-records-aim-to-light-up/.

Subsidies for Nuclear are required and it sucks. However, it can easily replace coal/oil. With solar your still stuck with having a back up power plant. which generates the dreaded co2. The goal is to move quickly to a green energy source.

We have the means of storing/disposing of nuclear waste, if we could get the uneducated mass from the decision. You can glassify the waste and drop it in one of the subduction zones in the ocean. Sounds scary, but its actually quite safe way of permanently disposing of nuclear waste.

 

[eastmen]

Subsidies for Nuclear are required and it sucks. However, it can easily replace coal/oil. With solar your still stuck with having a back up power plant. which generates the dreaded co2. The goal is to move quickly to a green energy source.

We have the means of storing/disposing of nuclear waste, if we could get the uneducated mass from the decision. You can glassify the waste and drop it in one of the subduction zones in the ocean. Sounds scary, but its actually quite safe way of permanently disposing of nuclear waste.

I'd rather have as much energy generated at the point of usage . Do we really need power lines all over the place ?

I'd rather see them invest heavly in solar. I'd love to have every house covered with panels , cars , mobile phones , clothes , parking lots , and hell even roads if we are able to figure out a way to do that.

 

[hoho]

Define large. Because from what I've read, once you go beyond a few hundred miles, the correlation drops off dramatically.
...

And the variation between days tends to be very slow, much slower than the occasional shutdowns of more traditional power plants.

In Estonia we have websites reporting wind power generation in pretty much real time, e.g this: http://www.4energia.ee/online/veeb/chart2/7p.php?park=pakri
That small park has total peak output of 18,4 MW and average yearly production of 53 GWh giving it roughly 30% efficiency.

Is there similar data availiable for larger installations, preferrably spread over huge areas?

And solar is getting better every day . Today two start ups announced the most efficent panels yet.

How efficient were they? How much better can they theoretically get?
Aren't usual panels close to around 20% efficiency in real-world use at the moment? I'd be surprised to see that double before we get fusion reactors

 

[KimB]

Solar is about 1 order of magnitude more expensive than wind which is bad.

Huh, what? Solar, right now, is about as expensive as coal power. I may be mistaken, but I don't think wind power is one tenth that cost.

 

[KimB]

There is nothing bad about wind or solar, but neither are ready to be prime energy generating sources for the world. If you want clean energy, nuclear is the way to go. In a few years, that might change. However it is not today.

It's the other way around, epic. Nuclear may be required to fill in the gaps of baseline power generation that solar and wind leave behind, but just as a practical matter we can build far, far more solar and wind power generation right now than we can build in nuclear power generation.

 

[KimB]

I've been hearing about how solar is just around the corner for almost a decade. When it's ready for prime time it will succeed without any subsidies. We are not there yet.

Yes, we are. Solar panels have reached cost parity with coal power at retail. That is to say, the cost of buying electricity from a coal-fired plant and buying some solar cells to supply your home with power is about equal. And the cost of solar panels just continue to drop, meaning that solar cells will easily be cheaper than the wholesale cost of coal power generation within 5-10 years.

My point is that until that time comes move away from coal/oil power plants to nuclear. That is if AGW is a serious problem.

Um, we can build solar and wind plants today without much cost premium. Nuclear plants take years to be built.

 

[KimB]

Is there similar data availiable for larger installations, preferrably spread over huge areas?How efficient were they? How much better can they theoretically get?
Aren't usual panels close to around 20% efficiency in real-world use at the moment? I'd be surprised to see that double before we get fusion reactors

http://en.wikipedia.org/wiki/File:PVeff(rev111205).jpg

But really, this isn't what is important right now. Instead, it is power generation vs. cost efficiency that is the important metric for getting solar cells adopted. Sure, maybe after a decade or so of building solar plants, when space starts to become a premium, then efficiency will start to matter more. But it doesn't matter much at the moment.

 

[Gubbi]

In Estonia we have websites reporting wind power generation in pretty much real time, e.g this: http://www.4energia.ee/online/veeb/chart2/7p.php?park=pakri
That small park has total peak output of 18,4 MW and average yearly production of 53 GWh giving it roughly 30% efficiency.

Is there similar data availiable for larger installations, preferrably spread over huge areas?How efficient were they? How much better can they theoretically get?
Aren't usual panels close to around 20% efficiency in real-world use at the moment? I'd be surprised to see that double before we get fusion reactors

Energi Net has a flash app that displays danish power production and import/export real time:
http://energinet.dk/Flash/Forside/UK/index.html

You can get production numbers by diving into the market reports here:
http://www.energinet.dk/EN/El/Engrosmarked/Markedsrapporter/Sider/default.aspx

Production numbers are usually on the bottom of page three. E.g. here's december 2011:
http://www.energinet.dk/SiteCollect...kumenter/El/Market report - December 2011.pdf

As is evident from december market data, wind power production exceeds consumption in short intervals, which is sold off. We have quite a liquid power market in Scandinavia / Northern Germany, a requirement for large scale wind power IMO.

Currently between 21 and 23% of electricity in Denmark is produced by wind power, the plan is to expand this to 50%. This requires the capability to store at least a days worth of consumption to be feasible IMHO.

Cheers

 

[Sxotty]

Is Nuclear possible without huge subsidies ?

Who pays for the waste disposal and where is it disposed of ? Who pays for the upkeep over hundreds if not thousands of years for the waste ?

At least solar is largely a one time fee and if the goverment devoted the money to it that going full nuclear would cost i'm sure prices of the tech would drop like a stone

http://www.engadget.com/2012/02/08/two-us-startups-break-solar-efficiency-records-aim-to-light-up/.

ACtually yes Nuclear is possible without subsidies, but generally companies like quicker payback times

The nuclear industry pays for disposal. They have been paying a tax for decades to pay for it. That is where all the money for Yucca mountain came from.

Solar isn't a one time fee since like anything it wears out.

Efficiency of solar doesn't matter. Cost does.

Huh, what? Solar, right now, is about as expensive as coal power. I may be mistaken, but I don't think wind power is one tenth that cost.

Show me your numbers. I see you are comparing home installation which is fair enough, but still foolish unless you are also planning to install battery backup at the home then the home owner will still have to pay T&D costs. I don't think you have any idea how cheap coal actually is.

 

[Gubbi]

Add all these up, and 1kWh of electricity produced by wind displaces far less than 1kWh of fossil fuel based production. You can even get increased emissions when trying to reduce output when wind power is plentiful, especially with coal:
http://docs.wind-watch.org/BENTEK-How-Less-Became-More.pdf
Looking at actual data from Texas (lots of wind generation there) this is what was found:

I know it depends on perspective, but the conclusion I draw from the above presentation is that the sooner coal is phased out the better. Wind is in-flexible in production, but so is coal. Coal is only really useful for base load. In Colorado daily demand variability has been met by gas fired turbines. They state wind causes problem because the variability of wind power production adds to the daily demand variability and thus coal power plants needs to throttle back.

Well gee, lower base power production by coal.

Wind will work when you can figure out a way to store energy well beyond what we can achieve with the hydro reservoirs we can find and use. Isentropic is promising company pursuing heat storage with 70% efficiency, so I hope that works out.

Agree. Large scale wind power ( (>25% power production from wind) will need some sort of temporary storage to reach 50%. If we want to go higher we need to store the energy chemically. Efficient storage capability would also change the economics of wind power radically.

Wow, I didn't think the effects could be that significant. Anyway, what is your current position on wind? When I was being negative about it (due to intermittency) you were telling me that it makes a fair amount of sense due to the surplus natural gas capacity the US has. However, I'm sure that much of that surplus is lower efficiency peaker plants.

There is still a long way to go.

There's an annual flux of kinetic energy of 3.8x 10^22 J in the atmosphere below 1km ¹, or 1.2 x 10^15 W. Aggregate installed wind power in the world as of 2010 was 194 GW. With a generous capacity factor of 35% that means we extract 0.005% of this.

*1: Smil, Vaclav. Inherent Limits of Renewable Energies. 2004

Cheers

 

[epicstruggle]

Coming from a respect site, so no shooting messenger:
http://www.spiegel.de/international/world/0,1518,813814,00.html

Will reduced solar activity counteract global warming in the coming decades? That is what outgoing German electric utility executive Fritz Vahrenholt claims in a new book. In an interview with SPIEGEL, he argues that the official United Nations forecasts on the severity of climate change are overstated and supported by weak science.

 

[hoho]

There's an annual flux of kinetic energy of 3.8x 10^22 J in the atmosphere below 1km ¹, or 1.2 x 10^15 W

Can we realistically use the energy from higher than, say, 100m? I would guess it's less than 10% of that due to objects nearer the ground "eating up" some of the kinetic energy.

Aggregate installed wind power in the world as of 2010 was 194 GW

Entire world today uses around 13TW of energy. About 3 decades ago it was half that. I have a hunch that power usage will keep rising in the future.

With a generous capacity factor of 35% that means we extract 0.05% of this.

How big areas of Earth do we need to cover to get meaningful amount of energy from it through wind turbines? By meaningful I mean enough to actually make up at least half of all energy production.

Also, considering the enormous storage needs you need to take into account the efficiency of that storage system as well and on the average day be able to produce more energy than is actually used so that you can fill that storage as needed.

Here is an interesting picture:

First a little explanation for the graph from here: http://physics.ucsd.edu/do-the-math/2011/12/wind-fights-solar/

Note that the best sites exceed 800 W/m², and large land areas approach 500 W/m². On the face of it, this looks far better than solar. But beware: the area in the denominator for wind power density is the area of the rotor—not the land area as is effectively the case for the solar map (panel tilt amounts to a 15% boost at 30° latitude, 41% boost at 45°).

A rule of thumb for a field of windmills is that they should not be closer than 5 rotor diameters side-by-side (relative to wind direction) and 10 rotor diameters in the wind direction (some use >4 and >7, respectively). Otherwise one windmill blocks the next, bogging down the wind and diverting the flow around the hindrance. The result is that each windmill stakes out a land area 50 square rotor diameters, while the rotor itself is π/4 square rotor diameters. The rotors therefore occupy only 1.6% of the land area, so that the raging 800 W/m² by rotor area becomes 13 W/m² by land area, and the inland hotspots become 8 W/m².

US uses around 4TW/h electricity (~25TWh together with liquid fuels and heat) per year or on average ~470MW but I'll round to 500MW for simplicity. average solar turbines get installed in the 500W/m^2 area US would need to cover around 1000000m^2 or roughly 1km^2 with wind turbines assuming 100% efficiency[/y]. Now correcting that with the real-world 1.6% we get around 62.5km^2. Now add in storage system and extra production power to fill the storage in reasonable speed and you'll need something like 150-200km^2 of turbines. Simple, right? Now add storage system via artificial dams and pumping water and you'll need to multiply that area usage by several orders of magnitude.


And another quote from same site:

The upshot is that a 1 m² patch of flat land in the Texas panhandle might get 200 W of average sunlight (downward corrected for latitude tilt), compared to 8 W of wind power. If we convert sunlight to electricity at 15% efficiency, and wind at 45% efficiency (typical numbers), we have 30 W vs. 3.5 W. Solar beats wind (in that same location) by an order of magnitude. Comparing optimal solar sites to optimal wind sites (taking 1000 W/m² by rotor area), solar wins by a factor of five.

So yeah, why on Earth would anyone want to use wind when direct solar is that much better and lacking moving parts should be siginificantly cheaper to maintain? Though yes, it still has the storage problem just like anything else that relies on solar in some form or another.

Obviously this was just my quick back-of-the-envelope math. The article linked that used far more accurate methods came up with theoretical potential for whole world at around 1TW.

 

[Gubbi]

Can we realistically use the energy from higher than, say, 100m? I would guess it's less than 10% of that due to objects nearer the ground "eating up" some of the kinetic energy.
Entire world today uses around 13TW of energy. About 3 decades ago it was half that. I have a hunch that power usage will keep rising in the future.
How big areas of Earth do we need to cover to get meaningful amount of energy from it through wind turbines? By meaningful I mean enough to actually make up at least half of all energy production.

I'm just saying we're a long way away from affecting global wind patterns, not that we need to meet world demand for electricity by wind power alone.

US uses around 4TW/h electricity per year or on average ~470MW but I'll round to 500MW for simplicity.

The U.S. consumes 4000 TWh electricity per year, that's 456 GW ( jigga-watts )

Cheers

 

[hoho]

I'm just saying we're a long way away from affecting global wind patterns, not that we need to meet world demand for electricity by wind power alone.

True but my point was wind is rather pointless to pursue anyway.

The U.S. consumes 4000 TWh electricity per year, that's 456 GW ( jigga-watts )

Cheers

Yeah, thanks for the correction. I somehow missed billion between million and trillion. So basically instead of that 150-200km^2 you'd need 1000 times that (+ storage needs)

 

[Gubbi]

True but my point was wind is rather pointless to pursue anyway.

Your point is pointless. You want a single solution to meet *all* of U.S.'s demand for electricity. Nobody ever claimed that.

Wind power makes sense in lots of places in the world where you have stable wind patterns. That implies coastal regions and thus is a poor single solution for the U.S. which stretches across a effing continent.

Danish electricity demand could be met by 10 London Array sized facilities, perfectly doable (10 15x15 km installations). Multiply by 10 for the U.K.

Cheers

 

[hoho]

Danish electricity demand could be met by 10 London Array sized facilities, perfectly doable (10 15x15 km installations). Multiply by 10 for the U.K.

In what way do they have the storage problems solved? By offloading it to other countries to provide them with fossil-fuel based electricity?

 

[Gubbi]

In what way do they have the storage problems solved? By offloading it to other countries to provide them with fossil-fuel based electricity?

That's a differnet matter than the area argument, no ?

But you know they haven't solved the storage problem yet. I already stated that myself earlier: To expand wind power production from 25% of average consumption to 50% you need to be able to store a days worth of consumption. Beyond 50% you need to store the energy chemically (synthetic methane, ammonia, hydrogen, whatever).

Cheers