The Science of Climate Change

SpaceNut · 2019-01-17 20:36:31

Seems everything gets a subsidy these days....

louis · 2019-01-20 15:31:24

Another study suggesting wind and solar are winning on a LCOE analysis.

https://www.windpowerengineering.com/bu … inds-bnef/

Battery storage is now increasingly becoming cost effective. "Batteries co-located with PV or wind are becoming more common. [The] analysis suggests that new-build solar and wind paired with four-hour battery storage systems can already be cost competitive, without subsidy, as a source of dispatchable generation compared with new coal and new gas plants in Australia and India."

I'm wondering whether part of the solution might be power to gas - artificial manufacture of methane (using wind and solar energy during periods of surplus) especially in countries where there is already the gas turbine infrastructure in place. Marginal cost theory comes into play here. If you've already got the gas turbine infrastructure, and you have significant periods where wind and solar produces surpluses then it might well make financial sense to produce artificial methane even though it is an expensive process, since the cost of the excess wind and solar energy is effectively close to zero.

SpaceNut · 2019-01-20 18:11:18

There is a bit of bias in the story as indicated by all the spam ads but the chart is factual data. Levelized Cost of Electricity (LCOE) is a means to make the numbers mean anything.

Most solar installations are fixed location tied to a grid so no batteries and much lower costs.
The same holds true for the tracking kind as well since the owner is trying to maximize profits.

louis · 2019-01-20 18:43:19

LCOE is what it says on the can: levelised cost of energy (without subsidy) at the point of purchase. It's not a description about how to construct a grid that is 100% reliable, or how much it costs to do that.

The cheaper solar panels (or film) become, the less important tracking becomes. Proportionally, the lower the cost of solar, the higher the cost of tracking.

Yes, we know that currently most solar installations don't have battery storage but the point of the article is that already in Australia and India unsubsidised solar plus storage are beating even instant-energy gas turbines. That is significant. It won't immediately translate to the whole world, but that is the trend.

SpaceNut wrote:

There is a bit of bias in the story as indicated by all the spam ads but the chart is factual data. Levelized Cost of Electricity (LCOE) is a means to make the numbers mean anything.
https://3ohkdk3zdzcq1dul50oqjvvf-wpengi … -chart.jpg
Most solar installations are fixed location tied to a grid so no batteries and much lower costs.
The same holds true for the tracking kind as well since the owner is trying to maximize profits.

kbd512 · 2019-01-21 13:52:44

Wind Power Physics and Cost

I've seen no references to the mathematics involved in wind power generation posted here, so I thought I'd post a short video to try to explain why I know the wind power concepts from Makani Power and Kite Power Systems have so much more potential than any form of static wind turbine ever will. The math involved drives the cost of a solution. We can make some useful basic inferences about why the cost of static wind turbines won't be substantially reduced without a reduction in materials costs or quantities required.

Louis still believes that prototypical wind turbines will simply become cheaper and cheaper over time, but the newer wind turbines being built have become larger, incorporate newer and more costly materials, and have thus become more expensive to manufacture, transport, and operate. It's possible that automation of blade fabrication could reduce blade manufacturing costs, but all of these newer machines have the weight of small naval combatants yet they're substantially larger. Producing them in the quantities required to generate significant power will be extraordinarily expensive, time consuming, and require incredible resource expenditures at total output levels that substantially reduce reliance upon hydrocarbon fuels.

Q: How "incredible" is incredible?

A: Well, if we tried to use the comparatively dainty 2MW onshore static wind turbines we'd need a land area about the size of the British Isles (all of them) to provide 2% of the world's year-over-year increase in demand for electrical power. We're talking about hundreds of thousands of machines that weigh 350t or more. That's why wind turbine power never really took off in the US. Apart from farm land or other unused areas of federal lands, which invariably mandate new power infrastructure additions, it's just too land and resource intensive.

The link below adequately illustrates the absurdity of onshore wind power as a replacement for fission reactors:

Wind Turbines and Fission Reactors Compared

The comparatively dainty and easy to transport 350t onshore 2MW wind turbines from Vestas or GE or Siemens require 2,077 machines spread over 318 square miles to match the output of a 1,154MW fission reactor that occupies approximately 1 square mile. That's with a sub-optimal spacing of 1 turbine every 0.15 per square miles instead of 1 turbine every 0.2 square miles, which is what NREL recommends. The fission reactors at San Onofre only occupy .13 square miles or something like that, but it's a bad example and not representative. 1 to 2 square miles is plenty for 1 to 4 GW-class fission reactors.

For my American readers, the combat weight of a M1A2 SEPv2 Abrams MBT is around 65t. For my British readers, the combat weight of a FV4034 Challenger 2 MBT is around 75t. That means the transport weight of one of these 2MW wind turbines is about the same as 5 of the latest and greatest main battle tanks. The concrete transport weight is about the same as 14 main battle tanks. Over 2 to 3 decades, the total mass of all 9,000+ of the US M1 tanks produced / upgraded was around 585,000t. Each GW-class wind turbine farm will weigh more than that in terms of steel alone. Each turbine is shipped in pieces, obviously, but we're talking about thousands of truck loads and tens of thousands of concrete trucks to anchor the turbines to their bases. We're going to cover an area of 17.32 miles by 17.32 miles with these turbines.

There's enough steel alone in those wind turbines to account for the total full load tonnage associated with 7 of the largest aircraft carriers on the planet to replace a single GW-class fission reactor. I'm not sure when, precisely, that the absurdity of such proposals will begin to sink in. The largest super tanker in the world, Shell's "Prelude", weighs 600,000t when fully laden with LNG. It's larger than the Empire State building, with a length of 1,601 ft and a beam of 243 ft. We need more steel than the largest ship in the world for each GW-class reactor that we attempt to replace with wind turbines. On top of that, truly incredible quantities of steel reinforced concrete are required. Each wind turbine pad requires about 1,000t of concrete, so 2,000,000t+ of concrete per reactor replacement. Anyone who believes that's going to be cheap and fast is not connected with reality. Each GW-class PWR requires about 40,000t of steel and 200,000t of concrete, which explains why the up-front cost of reactors is so high. I've grossly distorted just how much steel and concrete is required simply to produce figures with equivalent yearly output. If availability or capacity factor is taken into account with the wind turbine solution, material tonnages required begin to diverge from realistic yearly steel outputs and either a major portion or total yearly steel production is devoted to wind turbines. At a global scale, total materials tonnages and manufacturing time become figures of merit. Thereafter, we have to sustain this output level every year in terms of new manufacture and recycling. A reactor is buy once, cry once.

For anyone who is interested in learning about basic wind turbine physics, watch the following YouTube video:

Wind Power Physics

Wind Power Equation

P(wind power) = .5 * ρ(air density) * A(area) * V^3(wind velocity)

Explanation of Terms

1. "P" is the maximum theoretical output power expected to be generated by using a wind turbine with a given blocking area, for a given air density and velocity; this theoretical value is subject to Betz's law, which states that for reasons related to conservation of mass and momentum, an ideal wind turbine could capture 59.3% of the kinetic energy in the wind; wake rotation is what the actual physical phenomenon happens to be and why faster tip speed is so desirable until transonic velocities are achieved; the Betz coefficient applies to all open disc / rotor wind turbines and although a diffuser could extract additional kinetic energy from the wind, the law is still applicable to the entire device

2. "ρ" / "rho" is air density; for a system without a significant air density change from STP, rho ~= 1.225; STP is Standard Temperature and Pressure at Earth's defined as 1.225kg/m^3 atmospheric sea level by ISA, although water vapor or humidity obviously changes that figure; "~=" is my substitute for "similar or equal to", since the LaTeX symbol for the same doesn't print well; recognize that IUPAC and ISA define STP differently, but use different temperatures in their definitions; please also note that NTP and STP are not the same thing

3. "A" is the area that is blocked or swept by the turbine blades, in square meters; in the case of a prototypical propeller-like wind turbine blade arrangement, this can be expressed as pi, or 22 divided by 7, multiplied by the radius squared, or simply pi * r^2; for other configurations, the geometry of the parts that the wind acts upon determines what the effective area happens to be

4. "V" is the straight line wind velocity, in meters per second, cubed; if the wind is too turbulent or slow, then the available kinetic energy in the wind is exponentially reduced

Practical Meaning of the Wind Power Equation

From the equation, it should be obvious that two terms have significant influence on the wind kinetic energy in the wind that can be converted to electrical power. Those two terms are "A" (swept area) and "V" (wind velocity).

Apart from moving wind turbines to sites with greater average wind velocities (places with more wind kinetic energy measured over a period of time), static wind turbine designers have no control over this factor. Unfortunately, wind velocity has the greatest influence on power output of a practical static wind turbine solution. It should also be obvious that even if a wind turbine spins at very low wind velocity, it generates very little power.

At 14m/s, which would be the average wind velocity for the North Sea but off the graph in the video, the wind kinetic energy moving through every square meter of space approaches 1kW. As indicated in the video, the maximum amount of power that could be extracted from a conventional wind turbine design would be around 0.593kW per square meter. In all actual and practical implementations, the convertible kinetic energy figure will be less than that.

The one design parameter that static wind turbine designers have control over is the size of the wind turbine. That is what has driven the trend towards greater wind turbine blade length and thus swept area. This design optimization quickly runs into the material limits of known Carbon Fiber composites around 120m, beyond which the weight of the blades has a severe detrimental effect on output by constraining operable speeds or the force of the wind acting on the blades exceeds the limit load of the composite materials used. Recall that CFRC's are only stiffer than GFRC's, not stronger, and even that stiffness property is highly directional in nature.

This is why I advocated for two things in my conversations with Louis.

The first was large static offshore wind turbines. Wind velocity has the greatest effect on output. If a more constant and higher velocity wind input can be obtained with good siting, then that's what we want. Prototypical onshore wind speeds are simply not sufficient unless properly sited. UK has some of the best wind resources available in Europe.

The second was much smaller airborne wind turbines. Again, wind velocity has the greatest effect on output. Even a small wind turbine can produce a lot of power at sufficiently high velocity. The only way to get that velocity up where we want it to be is to start higher in the atmosphere where average wind velocity / power is greater and to use the physics of flight to our advantage.

Let's recap here:

The length of the blades associated with the 12MW Haliade-X are approaching the structural integrity limit of sufficiently stiff and strong carbon fiber blades capable of handling the acceleration loadings. Perhaps future larger wind turbine blades can use CNT's or other super fibers, but for now CNT's are too expensive. The wing shape of the blades could potentially be varied to produce more aerodynamic lift, but that would require some kind of tensegrity-adapted structure that needs to be developed and extensively tested. As of now, nothing out there would survive the acceleration loads applied if the blades were much larger than those of Haliade-X. The blade tips of Haliade-X could also easily approach Mach 1 in a storm, which would damage or destroy the blades if the turbine wasn't able to be shut down.

Q: Why can't we just increase the number of blades to increase the torque since torque is what generates power?

Well, we could but torque alone doesn't determine power output. That was explained in the video for those who bothered to watch it. Velocity has the most significant effect on power by far. That's why Formula 1 engines rev to insanely high RPM's. Big power can be generated by big torque at low velocity if the structure is stout enough, but low mass and high velocity clearly has a disproportionately greater effect on power output.

Q: Why can't we just make the wind turbine taller?

A: We could, but again, at the expense of materials mass and thus cost. Apart from using composites in the nacelle and tower, we can't make the structure substantially lighter if it's built to survive and we can only reduce mass using more expensive composites or more expensive construction techniques to make a given mass of material stiffer at a given weight. Nearly any optimization we attempt to make here will detract from the service life of the product or greatly increase cost or both.

Q: Why can't we just make a more efficient wing?

A: We could, and yet again, current designs are already high optimized to produce a lot of aerodynamic lift at wind speeds useful for generation of power for long blades. Vortex generators might improve laminar flow at lower wind speeds, but there's no power in low wind speeds. Fences might improve flow and reduce wake rotation. Compliant structures could potentially increase tip velocity by varying geometry along the blade to increase lift.

Q: So, if we can't do any of that then why can't we make a more efficient generator?

A: So far as we know, generators can't be more than 100% efficient and we're within 1% to 2% or less of the maximum theoretical value.

I can't make the blades any longer due to the properties of available and affordable materials, the electric generators are already at 98% or even 99% efficiency, making the mast significantly taller requires far more material to maintain structural integrity, cranes that don't exist will be required just to install even longer blades on higher towers, and if I put the machine on land where maintenance is easier I get lower average wind speeds. Apart from using composites in the nacelle and tower instead of vast quantities of steel, there are very few other practical ways to decrease cost and improve output. It's just a very expensive power generation technology that's very tightly constrained by practical physics and materials properties. There's nothing cheap about wind turbines the size of the Eiffel Tower, either.

Conclusions

I think current static wind turbine technology is pretty close to being tapped out. Anything we attempt to optimize is quite likely to substantially increase cost from here on out. There's very little practical margin for simultaneous growth of the blades and tower / mast height to improve consistency of output / availability / capacity factor with a simultaneous cost reduction. No significant improvement on average wind velocity is possible without extreme mast heights and/or better siting, but that has the greatest single effect on output in an already optimized design. The few other remaining optimizations possible have breathtaking price tags attached to them for very little improvement in output.

The airborne wind turbine drones and kites offer a far more compelling case for affordable wind power than static wind turbines. Either drones that generate power from high velocity airflow directed over smaller blades / propellers or kites that pull on cables connected to stationary generators via hydraulic or pneumatic accumulators, have incredible growth capabilities with comparatively modest costs. The kites in particular are just pennies on the dollar compared to large static wind turbines and that technology comes from the UK, making it an affordable home-grown solution.

louis · 2019-01-21 15:12:25

None of what you write explains why wind energy has essentially been coming down in price substantially for years and why experts in the field expect prices to come down further in the future.

One reason that costs will continue to fall is that in the wind energy sector there are lots of turbines that are 10-25 years old. Their turbines will be replaced by more modern turbines and blades as we go forward.

Another is that we won't have to build all the infrastructure such as platforms, towers, service tracks and so on when turbines are "refreshed".

A third reason is that automation and robotics continues reduce the cost of manufacture.

Lastly, minimising human maintenance input can produce significant cost reductions.

You seem to underestimate the potential for further growth in US wind energy. From Wikipedia:

"According to the National Renewable Energy Laboratory, the contiguous United States has the potential for 10,459 GW of onshore wind power. The capacity could generate 37 petawatt-hours (PW·h) annually, an amount nine times larger than current total U.S. electricity consumption. The U.S. also has large wind resources in Alaska, and Hawaii.

In addition to the large onshore wind resources, the U.S. has large offshore wind power potential, with another NREL report released in September 2010 showing that the U.S. has 4,150 GW of potential offshore wind power nameplate capacity, an amount 4 times that of the country's 2008 installed capacity from all sources, of 1,010 GW."

Whilst I wouldn't expect this potential to be fully realised, I could imagine a scenario where wind energy could produce 4 times the 6.33% of all generated electrical energy it currently produced in 2017 - so more like 25% and maybe 50% of all automative electricity.

kbd512 wrote:

Wind Power Physics and Cost
reply post content #105
.

SpaceNut · 2019-01-21 16:39:18

This is the type which Louis is firmilar with

http://www.sustainable-hyderabad.in/dif … windmills/

but there are lots of others and depending on where the wind is coming from other types may work better.

Dutch windmills

https://naturalenergyhub.com/wind-energ … ent-types/

There are two types of designs in windmill:
Vertical axis windmills
Horizontal axis windmills

Basic designs but there are more to consider

https://teachergeek.org/wind_turbine_types.pdf

https://www.eia.gov/energyexplained/ind … f_turbines

https://www.turbinesinfo.com/types-of-wind-turbines/

Vertical Axis Wind Turbines (VAWT)
VAWT is more efficient, cheaper, simpler, and easier to maintain as compared to HAWT because VAWT always faces the wind which is the inherited characters of the structure of this turbine.

kbd512 · 2019-01-21 17:00:25

Louis,

Louis wrote:

Post #106

The prices aren't going down! Good grief, man. Stop reading assertions. Start looking at the purchase prices for actual wind farms and actual maintenance costs. Playing games with the numbers doesn't affect how much cash you have to hand over to buy the equipment. Trying to play "hide the costs with the subsidies" doesn't work when the fraud becomes large enough. Your basic argument is "but, but, but Bernie Madoff made 20% in the market every year". Sure he did. How'd that work out?

The 6MW turbine doesn't cost less than the 2MW turbine and the 12MW turbine doesn't cost less than the 6MW turbine. You can't make an aircraft that weighs three times as much as a smaller one less expensive to buy. Period. I'm looking at the purchase prices associated with real wind turbines. If you scale up your ideas enough, the purchase prices alone matter quite a lot.

Turbines will cost less when they're replaced, but labor and material costs are going down every day, year-over-year, right?

Nobody is actually reusing any infrastructure, either. By the time replacement is required, new infrastructure is also required. We don't refurbish old wind turbines. The existing infrastructure rusts in place while new wind turbines and infrastructure are built around the new turbines.

The parts of the wind turbines that require machining are already done with robots. A CNC machine is a robot. Every manufacturer on the planet is already using those.

Wind turbines require maintenance to keep the blades clean, the bearings lubricated, and the heavily loaded structures inspected for cracks. Maybe we can make robots to perform that work, but then the humans will be servicing both the wind turbines and the robots unless we also have robots that perform repairs on the wind turbines and themselves.

Regarding the theoretical output achievable from NREL by covering nearly every square inch in a wind turbine farm:

10,459GW / 1.154GW (the reactor from the example) = 9,603 (the number of wind farms required per GW-class reactor)

9,603 * 318 (the land area required for 2,077 of the 2MW wind turbines at suboptimal spacing, according to NREL) = 2,882,116 square miles

The US is only 3.12 million square miles. No matter how much power is theoretically available, that achievable output level is wildly impractical.

2,882,116 / 9 (to provide the amount of power we need right now) = 320,235 square miles

Texas = 268,596 square miles

Forget about devoting every square inch of land in an area greater than Texas, though. That's 2,216,159 wind turbines.

We need at least 664,847,700t of steel.

The entire steel output in 2017 for the People's Republic of China, by far the world's largest steel producer, was 831,700,000t.

Who needs buildings, roads, or bridges when your ideology is at stake?

Even if we only get 25% of our power from wind turbines, something else still has to provide the other 75%. Rather than making a large portion of the US uninhabitable, I'd rather use more intelligent designs.

kbd512 · 2019-01-21 17:16:55

SpaceNut,

SpaceNut wrote:

Post #107

I take it you didn't watch the video that I posted a link to. The other types of windmills you depicted that "may work better" are explained as well. I guess it depends on what you mean by "work better".

louis · 2019-01-21 17:38:40

None of those other designs are anywhere nearly as cost efficient as the ones you rightly say I am familiar with.

SpaceNut wrote:

This is the type which Louis is firmilar with
http://www.sustainable-hyderabad.in/wp- … ndmill.jpg
http://www.sustainable-hyderabad.in/dif … windmills/
but there are lots of others and depending on where the wind is coming from other types may work better.
Dutch windmills
https://naturalenergyhub.com/wp-content … uture.jpeg
https://naturalenergyhub.com/wind-energ … ent-types/
There are two types of designs in windmill:
Vertical axis windmills
Horizontal axis windmills
Basic designs but there are more to consider
https://teachergeek.org/wind_turbine_types.pdf
https://www.eia.gov/energyexplained/ind … f_turbines
https://www.turbinesinfo.com/wp-content … rbines.jpg
https://www.turbinesinfo.com/types-of-wind-turbines/
Vertical Axis Wind Turbines (VAWT)
VAWT is more efficient, cheaper, simpler, and easier to maintain as compared to HAWT because VAWT always faces the wind which is the inherited characters of the structure of this turbine.

SpaceNut · 2019-01-21 17:38:57

Sorry Kbd512 as I am not able to watch the video on the home computer but would at work tomorrow.
It comes to match charateristic of what do you want out for the energy type for the level of winds that are recieved.

SpaceNut · 2019-01-21 18:00:22

Not all applications of a windmill are for commercial use.

You missed the fact that the first requires a very tall mast and open suroundings which would not be possible in the NH area or functional only at the peaks of mount hill terrain.

To which the others would produce power at lower altitudes and closed in spaces for residential customers. I live on a sloping hill mountain range with which the mountain blocks air flow all but from the valley rising toward the peak for a direction.

Making even if I could clear the range area for the large mast unit next to only half useful. The mast and blades would need adjusting for the terrain to allow for the windmill to turn for winds that are cross ways to the mountain.

kbd512 · 2019-01-21 18:24:39

SpaceNut,

The tall masts are required to generate consistent power output. The wind speeds and consistency near the ground are not as great as those found higher in the atmosphere, at higher elevations, or in areas with fewer impediments to the natural flow of the wind. Atmospheric turbulence from operation near the ground also dramatically reduces output. The solution to your siting issue is to put the wind turbine on the peak of the mountain. Ultimately, the kite solution is better if total mass and cost are considerations.

louis · 2019-01-21 19:20:58

Re the land area thing - that's siting, so the turbines don't interfere with each other. It doesn't stop the land being used for grazing or many other uses. So it's very misleading what you're doing, suggesting all that land is "taken up" by wind energy generation.

LCOE is levelised cost without subsidy. It's basically all costs (including financing) divided by number of MWhs produced. The levelised cost seems to go as low as $40 per MWh for onshore wind, or $20 with subsidy. So I am presuming the subsidies are worth around $20 per MWh.

This report has plenty of detail, most of it contradicting your claims.

https://emp.lbl.gov/sites/default/files … iefing.pdf

One thing I hadn't realised is that the capacity factor has now increased so much. With new turbines hitting 42% in some areas, that's very impressive.

With wind energy already providing over 6% of the USA's electricity I can't see why that can't carry on expanding to reach maybe 25-35%. I think within the next 20 years though solar will take the lead.

I'm getting 207 million tonnes of steel, not 664 million. But you'll probably only be going up to 30% wind - maybe 40% at a stretch. If 30% then that would be 62 million tonnes of steel. 10 year programme - that's 6.2 million tonnes of steel per annum. Starts to sound quite reasonable then doesn't it?

If it's 30% wind generation, I think you'd be initially looking to find another 40% from renewables (PV solar, hydro, geothermal, tidal, sea current, wave, energy from waste, bio fuel). The remaining 30% would be coming from gas, coal and nuclear. But gradually I think you would phase those out with gas being last to go. Within another 40 years solar plus storage will be so cheap and reliable there will be no need even for gas. We might also have orbital solar available as well.

kbd512 wrote:

Louis,
Louis wrote:
Post #106
Response post #108
The prices aren't going down! Good grief, man. Stop reading assertions. .

Last edited by louis (2019-01-21 19:50:25)

SpaceNut · 2019-01-21 19:38:28

Industrial wind turbines are a lot bigger than ones you might see in a schoolyard or behind someone's house. The widely used GE 1.5-megawatt model, for example, consists of 116-ft blades atop a 212-ft tower for a total height of 328 feet. The blades sweep a vertical airspace of just under an acre.

So just how many can I build on my lot with a dimension of 110 ft road frontage by sloping down hill 400 plus ft as some of that is a drop grade of 60 ft over that distance.

so the answer is one in the near middle of the lot...at even a greater hieght to make sure the blades clear and the lot would need to be clear cut and fenced to keep others out. The greater hieght would also need air FAA aprovals, pass the zoning laws for the structure ect....

That is why the electric companies, gas companies are doing the installing of the large windmills and the electric companies plus gas companies are the subsidizers of the projects.

louis · 2019-01-22 11:42:58

Another helpful analysis showing why wind energy costs will continue to fall...another 50% reduction projected up to 2030, but could be even more dramatic:

https://www.ecowatch.com/wind-power-cos … 01894.html

That would mean in the USA that at the lower end costs were down to 2-2.5 cents per KwH.

Last edited by louis (2019-01-22 11:44:11)

kbd512 · 2019-01-23 18:00:34

Louis,

Louis wrote:

Post #114

I don't think it's misleading at all at the scale you're advocating for. There's only so much prime real estate for optimal siting of the machines and then the wind power advocates will invariably want to start encroaching on residential areas, as they've already done in Canada. People can't live within a kilometer of the things. If you think you can, then try it some time. I take no issue whatsoever with farmers permitting the power companies to site wind turbines on their farms. It's their land, their choice, and I wouldn't lift a finger to stop them so long as everyone else isn't required to pay for it.

All of the growth seems to be associated with PTC and your assumption about the subsidies is nearly spot on. It's around $23/MWh. Remove the subsidies and the capacity additions magically vanish. Funny that. It's almost as if it wasn't cost effective without them. The cost savings realized thus far are closely tied to mass production and improved maintenance practices, as the report indicates, not less expensive machines or labor costs since those factors continue to increase year-over-year. Look at page 42 of the report to see what starts happening around year 9 of operations. Also take note of the costs leveling off. Mass manufacturing and improved maintenance practices have already contributed their cost reduction effects to LCOE. The futures outlook section of the document pretty much indicates that the markets have found their price points. You can interpret that however you wish, but the explanations are pretty self-descriptive of the forces at play.

Something that only produces power 42% of the time is hardly what I'd call a reliable source. The capacity factors for the offshore turbines are over 50% and the new larger ones are supposed to be 60% or better. I can't speak for any operators, but as a capitalist I'd like my assets making money for me at least 50% of the time or more. I have a hard time believing that Warren Buffett and other investors don't expect to earn profits from operations.

Your tonnage figures are lower because you calculated something different than what I calculated. 30% wind is about 199MMt of steel, not 62MMt. I'm using tonnage figures from real 2MW to 3MW wind turbine designs from GE, Siemens, and Vestas for my calculations since those are what are actually being built in significant numbers.

Regarding long term operations and tonnages of materials, if the manufacturers can reduce their absurd levels of steel and concrete consumption then I'll lessen or withdraw my opposition. If there's a way to make composite nacelles and masts so these machines don't gobble up steel that corrodes or fatigues into uselessness in less than 20 years, then there's a sustainable proposition to the use of wind turbines. If not, then 20 to 25 year service lives followed by replacement and rust-in-place of existing infrastructure is not my idea of a sustainable power infrastructure. I'm sure the manufacturers love it, though.

What kind of storage are we talking about? I hope you're not still stuck on Lithium-ion batteries. There's not nearly enough Lithium in all known reserves just to supply everyone in the world with an electric car and recycling is never 100% efficient. If there was ever anything worth taking back from the moon or Mars or asteroids, then Lithium for batteries and Platinum group metals for fuel cells might be the first export products merely to keep pace with increased demand.

The future of energy storage is Ammonia fuel cells and Carbon-based super capacitors. Ammonia remains liquid at room temperature and sane pressure levels, it's no more dangerous than gasoline and a lot less explosive, and contains at least 1.5 times as much H2 as LH2 (I think the actual figure is 70% more, but I know it's at least 1.5 times more in a practical sense). We already have 50Wh/kg super capacitors (actually, batteries based upon super capacitor technology) that are $3/kWh. We have one of your fellow countrymen to thank for that. I sincerely doubt the cost of Lithium-ion batteries will fall 33 times and the massive roadblock to utility scale storage has always been production cost, service life, and maintenance requirements. The Carbon-based batteries win that argument rather convincingly.

louis · 2019-01-23 19:11:59

From Wikipedia:

"The total lithium content of seawater is very large and is estimated as 230 billion tonnes"

I think it much more likely we will find other more efficient methods of storage before we exhaust Earth's supplies of lithium.

There are many promising alternative techologies for storage. I think the most obvious one that will come into play is simply to manufacture methane from air and water. Once you get the cost of the electricity down to the 1 cent mark, a lot becomes possible.Air and water are basically free resources. Creating methane could be a very cheap process if you use the marginal energy of wind and solar when there is surplus energy - that energy also is virtually zero cost (it otherwise is simply "earthed"). The real cost of methane storage would be in the infrastructure - the pipelines and the gas turbines. But of course in many countries like Germany, the UK, the USA, Austria and so on that infrastructure already exists. My guess is that within the next 20-30 years artificial methane production will be cheaper than getting stuff out of the ground.

It is misleading to give the impression that wind turbine air current requirements preclude other land uses. Grazing and turbines make a very good marriage. The only land lost is really the service track and the turbine tower footprint.

Your calculations appear to suggest that each 2MW wind turbine would contain about 300 tons of steel:

"That's 2,216,159 wind turbines.

We need at least 664,847,700t of steel."

But this wind-spectic site suggests that the figure is more like 30 tons of steel for a 2.3 MW turbine. Decimal point error?

"MidAmerican Energy announced they were about to build the tallest wind turbine in the US, a 2.3 MW 554 foot tall (with 173 foot blade extended) about the same as the Washington Monument. It will be 337 feet ground to hub, use 395 cubic yards of concrete, 63,400 pounds of reinforcing steel, and generate power when winds are 7 mph or higher, producing the most wind at 29 mph. Important figures such as cost, capacity, maintenance, and so on not (Remer)."

http://energyskeptic.com/2015/900-tons- … -windmill/

Well even if your figures are correct, 200 million tonnes of steel would amount to 20 million tonnes per annum on a 10 year programme. That's a lot of steel but not an impossible or absurd amount. The US produces 80 million tonnes per annum. This would be a programme that would have an end date and thereafter you would be replacing infrastructure as required.Eventually you might settle down to using maybe 5 million tonnes per annum.

kbd512 wrote:

Louis,
Post # 117
Louis wrote:
Post #114
I don't think it's misleading at all at the scale you're advocating for. .

SpaceNut · 2019-01-23 19:50:17

The manufacturing of larger windmills is a short term improvement until we need more power than what it can provide from the wind itr recieves. The larger diameter allows for more coils and magnets to be built into the design to create more power from the same rotation speed. At some point though we will not achieve any more power out as we will reach the limits of the materials to create the energy.

kbd512 · 2019-01-23 20:00:29

Louis,

If we discover an economical way to extract Lithium from seawater, then great. Thus far, all the various "let's extract this element from seawater" schemes have proven to be uneconomical. That's why we don't do it. It's not just dollars and cents, though, as sufficient energy is also required.

Water desalination is economically feasible with nuclear reactors. Some of the new types of solar cells also show great promise for various extraction processes, but those have to be further developed first.

Regarding land use, all wind turbines are operated in areas that have been clear cut. If the land is already in use for grazing, that's fine. Once again, the issue is that the wind power companies and governments want to encroach on residential areas.

I believe my calculations for steel usage to be accurate and representative, as I'm using manufacturer documentation. I don't care about what your website says unless the name "GE", "Vestas", or "Siemens-Gamesa" appears in the URL or documentation. I'll look through some more verifiable sources to see if I can find something approximating your figures, which I think are far too low because it looks like you substituted the tonnage of rebar in the concrete for the tonnage of steel in the wind turbine itself. The reason I believe my figures to be accurate and representative is that the tonnages associated with the variant products with the same or very similar output are within 25t or so of each other, mostly accounted for by blade and nacelle design variations unique to a specific product. I've basically ignored the rebar because it's not a major cost component, except when we start scaling up the concept.

If the manufacturers start using more concrete and composites, which are functionally limitless materials, or less absurd quantities of steel, then I'll withdraw that objection. Right now they're using steel because it's easy to design from an engineering standpoint, fabrication uses existing assets from shipbuilding or structures fabrication, and the quantities of steel being consumed are low because annual wind turbine production is low enough for it to not matter that much. Much like the land use considerations, this is about what happens when we try to scale up.

louis · 2019-01-24 04:04:18

It was an anti-renewables website I referenced - so I assumed they were going for the max. You might be using offshore installations of course, rather than a world average or a US average. Most wind energy in the USA is onshore as I understand it.

https://debunkhouse.wordpress.com/2013/ … d-turbine/

kbd512 wrote:

Louis,
If we discover an economical way to extract Lithium from seawater, then great. Thus far, all the various "let's extract this element from seawater" schemes have proven to be uneconomical. That's why we don't do it. It's not just dollars and cents, though, as sufficient energy is also required.
Water desalination is economically feasible with nuclear reactors. Some of the new types of solar cells also show great promise for various extraction processes, but those have to be further developed first.
Regarding land use, all wind turbines are operated in areas that have been clear cut. If the land is already in use for grazing, that's fine. Once again, the issue is that the wind power companies and governments want to encroach on residential areas.
I believe my calculations for steel usage to be accurate and representative, as I'm using manufacturer documentation. I don't care about what your website says unless the name "GE", "Vestas", or "Siemens-Gamesa" appears in the URL or documentation. I'll look through some more verifiable sources to see if I can find something approximating your figures, which I think are far too low because it looks like you substituted the tonnage of rebar in the concrete for the tonnage of steel in the wind turbine itself. The reason I believe my figures to be accurate and representative is that the tonnages associated with the variant products with the same or very similar output are within 25t or so of each other, mostly accounted for by blade and nacelle design variations unique to a specific product. I've basically ignored the rebar because it's not a major cost component, except when we start scaling up the concept.
If the manufacturers start using more concrete and composites, which are functionally limitless materials, or less absurd quantities of steel, then I'll withdraw that objection. Right now they're using steel because it's easy to design from an engineering standpoint, fabrication uses existing assets from shipbuilding or structures fabrication, and the quantities of steel being consumed are low because annual wind turbine production is low enough for it to not matter that much. Much like the land use considerations, this is about what happens when we try to scale up.

kbd512 · 2019-01-24 07:52:04

Louis,

That NREL document you posted a link to says the wind industry is looking to upgrade from 70m to 135m masts / towers in the near future to increase their capacity factor. That means more tonnage of steel for the mast unless they switch to composites and concrete, as I've already alluded to in Void's "Happy Carbon Loving Future" thread in "Not So Free Chat".

Please skip to Section 2.14 - Tower Structure and note the weight of the 125m mast. The figure is for the mast alone. You can start doing some of your own research and gather the relevant documentation from GE and Siemens to see that I have not mis-stated or mis-quoted or used anti-renewable website claims to support my argument. That figure is the mast or tower alone, not the nacelle nor the blades nor the base pad.

General Specification V90–1.8/2.0 MW 50 Hz VCS

Note the tonnage figure for the 125m mast height. It says 335t, not 30t. The lowest mast height of 80m weighs 125t. Can you see how rapidly mast height and nacelle weight affect the mass of the mast? Your 30t figure is off by a factor of 4 at best and a factor of 10 if the industry does what it says it wants to do.

It should be clear by now that I don't make up things to support my arguments.

My arguments are based upon knowledge of what things weigh and what they cost.

I want you to start doing your own leg work and post the figures from GE and Siemens here. If I can find it, then you can find it.

We're going to argue from points of knowledge, not points of assertion. I don't care who makes the assertions, either, nor whether or not they support renewable energy technology. I support all forms of better power generation with proper scaling and cost control.

louis · 2019-01-24 08:23:17

See Table 6, page 13.

https://pubs.usgs.gov/sir/2011/5036/sir2011-5036.pdf

To get to 20% of US electricity supply from wind energy (with a mix of onshore and offshore), you would need 44 million tons of steel according to an official US Department of Energy study.

So your estimate of 664 million tons for 100% would seem to be out by a factor of 2.

A 10 year programme to get to 20% would be perfectly reasonable at 4.4 million tons of steel per annum.

kbd512 · 2019-01-24 12:29:34

Louis,

I already stated that the 664MMt figure related to providing 100% of our electricity, on a time-averaged basis, using wind power at current consumption levels. Obviously intermittency would require either more wind turbines or other sources for power. I then made a second calculation related to obtaining 1/3rd of our annual electricity consumption from wind. That's where the 199MMt figure comes from. Both calculations related to using onshore wind in the form of 2MW wind turbines with 135m towers / masts only (GE, Siemens-Gamesa, and Vestas, which is what we already have and use with shorter 70m masts). The issue with the shorter towers relates to capacity factor, which would be why the manufacturers want to upgrade to 135m masts.

The calculation made no attempt to determine cost or tonnage associated with a mix of onshore and offshore wind turbines. To my knowledge, the US has no permanent offshore wind turbine farms. We do have a number of test / prototype offshore wind turbine farms at places like Block Island. I would imagine that those are actually plugged into the grid, though.

louis · 2019-01-24 17:58:05

Well I am giving you what the official DOE study showed - which would be 66 million tons for 30% on a pro rata basis. rather than the 199 million tons you quote. Maybe you are working off lower capacity factors - they have certainly improved in recent years.

kbd512 wrote:

Louis,
I already stated that the 664MMt figure related to providing 100% of our electricity, on a time-averaged basis, using wind power at current consumption levels. Obviously intermittency would require either more wind turbines or other sources for power. I then made a second calculation related to obtaining 1/3rd of our annual electricity consumption from wind. That's where the 199MMt figure comes from. Both calculations related to using onshore wind in the form of 2MW wind turbines with 135m towers / masts only (GE, Siemens-Gamesa, and Vestas, which is what we already have and use with shorter 70m masts). The issue with the shorter towers relates to capacity factor, which would be why the manufacturers want to upgrade to 135m masts.
The calculation made no attempt to determine cost or tonnage associated with a mix of onshore and offshore wind turbines. To my knowledge, the US has no permanent offshore wind turbine farms. We do have a number of test / prototype offshore wind turbine farms at places like Block Island. I would imagine that those are actually plugged into the grid, though.

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