How much are wind farms useful to manage wildfires?

[Z0dCHiY8]

Sorry, but how in the world does your reply address my comment about you saying that there is no way to optimize the layout of a large 2-D windfarm?

what exactly do you want to optimize in wind farm? really :)

 

[berkeman]

what exactly do you want to optimize in wind farm? really :)

Wow, what parts of post #28 and #31 did you not understand? The CFD issues exposed and discussed in those posts are the most interesting parts of this thread so far, no?

 

[Z0dCHiY8]

Wow, what parts of post #28 and #31 did you not understand? The CFD issues exposed and discussed in those posts are the most interesting parts of this thread so far, no?

cfd has so a little w/ your idea about optimization of wind farm :) it's possible to optimize wind turbine for given range of wind speeds, but wind has unstable nature & most share of time turbine runs beyond optimal numbers. strong winds easily can damage turbine. So, only way of real optimization out there is only more & more gov funding.. it's more cool than cfd ("green" energy knows it so well) :)

 

[berkeman]

cfd has so a little w/ your idea about optimization of wind farm :) it's possible to optimize wind turbine for given range of wind speeds, but wind has unstable nature & most share of time turbine runs beyond optimal numbers. strong winds easily can damage turbine. So, only way of real optimization out there is only more & more gov funding.. it's more cool than cfd ("green" energy knows it so well) :)

And what are your thoughts and initial analysis of this image from that part of this thread?

 

[Z0dCHiY8]

And what are your thoughts and initial analysis of this image from that part of this thread?

gas turbine does better :)

 

[cjl]

Wow, thanks. That must make the design of windfarms very challenging. You'd need to factor in the varying typical wind directions and the available land area to try to optimize the number and placement of windmills.

Yeah, it's definitely an interesting problem. The trivial solution is of course to just space them out so they're all ~20 rotor diameters apart, so the wake effect is minimal, but that requires very large amounts of land, and incurs larger cabling and connection costs as well, so it's really not the best solution. In reality, detailed site surveys are done that determine the probability that wind will be coming from various directions, and then you tend to space them further apart in the direction that wind typically blows and closer together perpendicular to that. There's also the terrain effect to consider - you often want to place them up on ridgelines because the wind is more consistent up there, you have to consider where you want them relative to existing roads and infrastructure, and there's even the question of property rights if you're leasing the land from a farmer or something.

 

[cjl]

so many curious words :) let's take actual numbers == it's all open info..

let's compare w/ normal methods..

even simple cycle ones have been needed to smooth unstable production of "green" energy So, efficiency of wind turbine (30%) X capacity factor (60%) == overall efficiency (18%). And it's very good result for "greenies" :)

Why does the efficiency of the wind turbine matter at all? All that should matter is annual energy production and capacity factor (and cost of course - at the end of the day, we're trying for lowest LCOE here). Unlike coal or natural gas, where the effeciency impacts emissions and cost (since you have to buy the fuel), it doesn't matter at all if a wind turbine has to interact with a bit more wind to generate the electricity. In the industry, we generally aren't even trying to maximize efficiency. We're trying to maximize energy production for a given cost and load on the turbine, which usually involves intentionally decreasing the efficiency a bit off of optimum. The question you should be asking is this: what is the total cost of generating a GWh of energy? How does wind compare to solar compare to coal compare to combined cycle? That's what really tells you if they're useful or not.

(Also, for what it's worth, wind turbines are more like 40-45% efficient, but as I said above, it doesn't really matter anyways)

 

[cjl]

And I'm sorry to everyone for the multiple posts in a row here, but I can't just let a post like this go unanswered.

cfd has so a little w/ your idea about optimization of wind farm :)

Interestingly, this part is right. CFD on that kind of scale is just too computationally intensive, so you would usually use simpler models to approximate wake effects, turbulence, etc, and you'd use some kind of a coupled model like `FAST to see how the turbines behave.

it's possible to optimize wind turbine for given range of wind speeds, but wind has unstable nature & most share of time turbine runs beyond optimal numbers.

A wind turbine is designed based on the expected mean wind speed at sites at which it will be installed. Based on site assessments and turbine design, it's pretty easy to predict within a few percent exactly how much energy you expect a given site to make, and when it will be making that energy. The turbines also react to changing wind conditions, so the fact that the wind isn't perfectly steady isn't really a problem.

For a site with a mean wind speed around 9-10 m/s, you'd usually design the turbine to run pitched in all the way, extracting as much power as possible at all wind speeds up to around 12-13m/s. Above that, you hit the so-called "rated power", which is the number you actually see on the turbine brochure. If you see someone advertise a "6MW" turbine, that's the rated power. Above 12-13m/s, the turbine will make full power at all wind speeds up to 20-30m/s (depending on design), and above that will usually ramp down or shut off to protect itself. This also puts the lie to your following statement:

strong winds easily can damage turbine.

It's quite rare for strong winds to damage a modern turbine - there are a number of features in the controller that prevent this.

So, only way of real optimization out there is only more & more gov funding.. it's more cool than cfd ("green" energy knows it so well) :)

As it stands right now, wind energy is perfectly able to compete in many markets and locations with no government subsidy at all. The cost of the turbines has been dropping substantially over the past couple of decades, and the sophistication of the analysis that goes into their design, construction, and siting has drastically increased. It seems very likely to me that wind's share of energy generation will increase substantially through the next several decades.

 

[essenmein]

I would argue that a wind farm likely won't slow down a fire, but could easily make it worse.

Once the flames lick at those lovely flammable composite blades, they'll loose strength, fly off and contribute to the fires fuel.

 

[Z0dCHiY8]

Unlike coal or natural gas, where the effeciency impacts emissions and cost (since you have to buy the fuel)

no gasoline == it's very funny argument from "green" energy supporters. what about hidden usage of gasoline?

1. to build turbines takes gasoline (it takes dramatically less number of gas turbines to provide the same output ).
2. to maintain wind farms takes it yet again.
3. electrical grid becomes larger, more expensive & less reliable.
4. to smooth output == very funny story ;)
5. leads to energy crisis.. deep crisis, because "green" energy is worst of possible options.
==========

We now consider the production of 100 kWh electricity for which wind turbines have been built. After a year it turns out that on average 17,5 kWh have been supplied by wind, and the rest from conventional power plants, effectively serving as back-up. Assuming that these conventional plants delivered under optimum conditions, this required 82,5 x 270 = 22 275 g of hard coal, and 17,5 x 270 = 4 725 g of coal is saved producing this 100kWh.

However, the wind generated production has priority and forces the conventional stations to reactively ramp up and down. In the extreme case of the use of rapidly reacting open-cycle gasturbines only to achieve this, the efficiency falls from 55% to 30%.

Table 2 shows how the decreasing efficiency influences the saving of conventional fuel.

https://www.wind-watch.org/documents/hidden-fuel-costs-of-wind-generated-electricity/if we take into account all hidden gasoline, the're no savings at all == only losses ;)

I would argue that a wind farm likely won't slow down a fire, but could easily make it worse.

Once the flames lick at those lovely flammable composite blades, they'll loose strength, fly off and contribute to the fires fuel.

that's why there needs another design :)

 

[Z0dCHiY8]

It's quite rare for strong winds to damage a modern turbine - there are a number of features in the controller that prevent this.

good to hear, but-but..

Have you ever read that wind energy “is the cheapest energy source available?”

These claims are based on cost-estimates that assume the lifespan of wind turbines to be 30 years. However, according to the U.S. Energy Information Administration (EIA), the lifespan of wind turbines is about 20 to 25 years.

In Iowa, wind turbines are reaching the end of their lives even faster as MidAmerican Energy plans to repower turbines constructed in 2004, merely 14 years after they were installed.

To make matters worse, these cost-estimates attribute 30-year lifespans to every power plant – not just wind turbines – even though coal, nuclear, natural gas, and hydroelectric plants can generate electricity for more than 50 years.
https://www.americanexperiment.org/...ans-wind-turbines-result-higher-costs-energy/

 

[Baluncore]

How much are wind farms useful to manage wildfires?

Windfarms are no more use than a firebreak at stopping a wildfire. Wildfires have wide fire fronts, wider than any possible windfarm. Wildfires are not stopped by firebreaks as a wildfire will go over the top and around both ends. You can build hundreds of firebreaks for the cost of one windfarm.

While some forests should never be burnt, many forests are naturally shaped and regulated by fire. That natural process should be allowed to continue, or there will be an increased risk of catastrophic wildfire. It is clear that interference now makes things worse later.

Fire is also a human forest management tool that must be applied intelligently. If you can predict a wildfire in time to build a windfarm, (that will not stop it), you can instead build several firebreaks. Firebreaks make it possible to have a controlled burn at a safe time of the year, harvesting or burning adjacent blocks in different years. That sensible practice should prevent a catastrophic wildfire later.

Firebreaks require vehicle access and continued management. Firebreaks and controlled burning can really only be justified where a fire might spread into blocks of commercially valuable forest, or into a town.

To sum it all up. Wildfires are found in valleys with tall forests. Windfarms require level pads in rolling hills without trees. The two concepts are geographically incompatible.

 

[member 656954]

As it stands right now, wind energy is perfectly able to compete in many markets and locations with no government subsidy at all

Lazard's LCOE puts onshore wind as the consistently least expensive form of generation (with utility PV close behind), so @cjl is absolutely correct.

As for wind turbines somehow helping mitigate / fight forest fires, the only benefit they are likely to provide is reducing lightning strikes that start the fires in the first place. But if the turbine catches fire - which seems likely if they are in the path of a full-on forest fire - they release toxic fumes and and that's not a good outcome. Plus, the decommissioning gets even more complicated than normal.

 

[anorlunda]

This thread has become hopelessly confused. The OP question has been addressed. Thread closed.