Ivanpah thermal-solar plant: accidental weather modification or...?

On the desert road between Vegas and L.A. there is an area near the Searchlight turn-off that always seems to have unusual weather.

Every time I've driven through, there has been sporadic rain and wind. This last time, recently, there was no rain but there were unusual gusts of wind.

There's an alternative energy thermal-solar facility right there. It can easily be seen from the highway because the structures are so large. It had apparently just started operating on my last trip through.

I read about it first on ATS. Someone had put up a thread and there was a startling item that came up. The air temperature surrounding this facility, heated by mirrors, can reach 1000 degrees F.

The $2.2 Billion Bird-Scorching Solar Project

The $2.2 billion solar farm, which spans over five square miles of federal land southwest of Las Vegas, includes three towers as tall as 40-story buildings. Nearly 350,000 mirrors, each the size of a garage door, reflect sunlight onto boilers atop the towers, creating steam that drives power generators.

Temperatures around the Ivanpah Solar Electric Generating System's towers can hit 1,000 degrees Fahrenheit. Zuma Press

That's 150 degrees more than the temperature on Venus, the hottest planet in our solar system.

I don't know much about low and high pressure systems except for what the weatherman tells me but it occurred to me that this extreme could actually create an area of low pressure. Which could then give rise to the unusual winds in this area.

Pressure and Wind

In the atmosphere as air is heated it expands. Because it expands it becomes less dense and therefore, rises. This creates an area of low pressure at the surface.

As the warm air rises it begins to cool, eventually causing it to sink back to the surface creating an area of high pressure.

In general, air flows towards areas of low pressure and away from areas of high pressure.

Wind

Caused by pressure gradients. Wind is an attempt to equalize the pressure differential. This differential is the result of unequal heating of different portions of the Earth's surface.

Could this facility with its' ability to generate 1000 degree F heat be causing these winds? It sure seems like it could. As it continues to operate could it move on from dust dervishes/devils (which is what is happening there now) to tornadoes?

It's in the desert so, in summer, I imagine, it's going to be hot there anyway but it'll get up to 120 degrees F or so max; not 1000 degrees F. That's still a huge difference.

There were/are, in my view, some other anomalies with this plant which first made me suspect that it was not what it seemed. But as I try to understand wind and air pressure, it seems like this was just not very well thought out. What are your thoughts?

reply to post by luxordelphi


Hmm...

So that's where Bethesda got the idea fir Helios One in Fallout: New Vegas. Literally to a tee aside from the nuclear connotations. Strange...

Interesting stuff though. I mean it kinda makes sense. But, like you, I only really know what the weatherman tells me.

Kallisti

I read about it first on ATS. Someone had put up a thread and there was a startling item that came up. The air temperature surrounding this facility, heated by mirrors, can reach 1000 degrees F.

Where does it say the air temperature surrounding the facility can reach 1000º?

What your source actually says is this:

One reason: the BrightSource system appears to be scorching birds that fly through the intense heat surrounding the towers, which can reach 1,000 degrees Fahrenheit.

Air isn't being heated, the towers are (and they, in turn, heat water). Yes, an object near the focal point will get very hot due to the concentrated sunlight. That's how it works, but the air surrounding the towers is not being heated much. Air is transparent to sunlight, it doesn't absorb much of it so it doesn't get hot. If it did it would defeat the purpose of the power plant.

Think of it like a magnifying glass. The birds would be like ants getting burned. The air doesn't get hot but an object (the towers, birds) which absorbs the energy does.

That’s up from September’s tally of 34 mortalities, with 15 with melted feathers. The damage is likely caused by the birds flying through the intense radiation coming off the Ivanpah’s 300,000 reflecting mirrors — about 100,000 surrounding each of the plant’s three 459-foot solar towers. The tightly focused radiation heats liquid in boilers at the top of the towers, creating steam to run turbines.

voices.mydesert.com...

reply to post by Phage

Air isn't being heated, the towers are (and they, in turn, heat water). Yes, an object near the focal point will get very hot due to the concentrated sunlight. That's how it works, but the air surrounding the towers is not being heated much.

That doesn't make any sense. In order to heat up the water, the air has to be heated 4 times as much. Ever done any cooking over a hot stove?

Why does the air warm faster than the water?

The temperature of water changes slower than the temperature of the air because water has a higher heat capacity. Heat capacity is a property of a material that describes how much heat energy is required to change the temperature of a substance by one degree Celsius. About one unit of heat energy is needed to warm the air one degree Celsius. Four times more heat energy is needed to warm the water one degree Celsius.

Heat capacity is one reason why the surface water temperature in Narragansett Bay reaches a maximum at the end of the summer. The air temperature may be 80°F or more in June but the water temperature in Narragansett Bay is usually 65°F. The air temperature can also change a lot during the day but the water temperature doesn't change as much.

Ever jump into the Pacific on a hot day in order to cool off?

reply to post by luxordelphi

In order to heat up the water, the air has to be heated 4 times as much. Ever done any cooking over a hot stove?

Yes. And the kettle is being heated by the heating element or flame (which it is in contact with), not air. In fact, if I raise the kettle a bit above the heating element and let some air in between, it stops boiling.

Ever jump into the Pacific on a hot day in order to cool off?

Often. Doesn't have much to do with what we're talking about though.

reply to post by Phage

Yes. And the kettle is being heated by the heating element or flame (which it is in contact with), not air. In fact, if I raise the kettle a bit above the heating element, it stops boiling.

That's not the point. The point is that the air surrounding all this heating gets terribly hot - so hot that you need a fan to blow some of it away so that you can continue to stand there and watch the pot boil.

Further, your fried ant analogy:

Think of it like a magnifying glass. The birds would be like ants getting burned. The air doesn't get hot but an object (the towers, birds) which absorbs the energy does.

These are mirrors, not lenses. They are the size of garage doors. There are 350,000 of them.

reply to post by luxordelphi

That's not the point. The point is that the air surrounding all this heating gets terribly hot - so hot that you need a fan to blow some of it away so that you can continue to stand there and watch the pot boil.

That is exactly the point. I don't need a fan to watch my water boil and I can put my hand right next to the kettle with no ill effects because the air isn't hot.

These are mirrors, not lenses. They are the size of garage doors. There are 350,000 of them.

Yes I know. And working together they gather a lot of sunlight and focus it on one small area. Just like a magnifying glass does. The birds are burned by that concentrated sunlight, not hot air.

reply to post by Phage

That is exactly the point. I don't need a fan to watch my water boil and I can put my hand right next to the kettle with no ill effects because the air isn't hot.

So we've established that you're not a cook. And that you know nothing about the environment around a stove. That's great, I guess.

Yes I know. And working together they gather a lot of sunlight and focus it on one small area. Just like a magnifying glass does. The birds are burned by that concentrated sunlight, not hot air.

I thought we had just established that in order for the water in the steam thing to get hot enough to provide power, the air has to get 4 times as hot. What do birds have to do with that?

reply to post by luxordelphi

I thought we had just established that in order for the water in the steam thing to get hot enough to provide power, the air has to get 4 times as hot.

Not quite, but if you were using air to heat the water, yes the air would have to be hot. But you aren't, you're using solar radiation which is heating panels which heat the water. Just like a solar water heater heats water. Just like the heating element on my stove which heats the water in the kettle.

Phage
reply to post by luxordelphi

 

I thought we had just established that in order for the water in the steam thing to get hot enough to provide power, the air has to get 4 times as hot.

Not quite, but if you were using air to heat the water, yes the air would have to be hot. But you aren't, you're using solar radiation which is heating panels which heat the water. Just like a solar water heater heats water. Just like the heating element on my stove which heats the water in the kettle.

edit on 3/8/2014 by Phage because: (no reason given)

Whaaat? The same thing that's heating the water is heating the air: the sun. The same focusing onto the water is also focusing onto the air surrounding that water. At 2000 ft. or so (Ivanpah), water is going to boil at 200 or so degrees F. That means that the surrounding air, cooked by accident?, will get up to 800 or so degrees F. There is no way to focus sunlight coming from the mirrors onto a tower without also focusing it on intervening air.

I bet that place is hotter than hell, or hotter than Venus in any event.

reply to post by luxordelphi

Go outside on a bright, summer day with an ambient temperature of around 95F.
What's hotter: the air outside or the asphalt parking lot?

To add, if the ground burns your feet but the air doesn't, which is hotter?

reply to post by luxordelphi

There is no way to focus sunlight coming from the mirrors onto a tower without also focusing it on intervening air.

Air is heated by absorbing electromagnetic radiation or by being in direct contact with a warm surface. Air is mostly transparent to sunlight. Wavelengths which are absorbed by air are mostly absorbed before sunlight reaches the mirrors. The sunlight reflected by the mirrors is not absorbed by air. The sunlight reflected by the mirrors does not heat air because it does not contain wavelengths which are absorbed by air.

The water is not heated by hot air, it is heated by elements which do absorb the wavelengths of sunlight reflected by the mirrors so the elements get hot. Birds are not killed by hot air, birds are killed because they absorb the wavelengths of sunlight reflected by the mirrors so the birds get hot.

reply to post by abecedarian

Go outside on a bright, summer day with an ambient temperature of around 95F.

Or on a cool summer day for that matter. The effect would be better demonstrated.
How can the pavement be hot if the air is not?

luxordelphi
Whaaat? The same thing that's heating the water is heating the air: the sun. The same focusing onto the water is also focusing onto the air surrounding that water. At 2000 ft. or so (Ivanpah), water is going to boil at 200 or so degrees F. That means that the surrounding air, cooked by accident?, will get up to 800 or so degrees F. There is no way to focus sunlight coming from the mirrors onto a tower without also focusing it on intervening air.

You aren't understanding the cite you linked.

If you apply the same amount of energy to a mass of air and the same mass of liquid water, the air will heat up four times as much, because the specific heat of water is a tad over 4x the specific heat of air.

However, the caveat here is "apply the same amount of energy". The black surface of the boiler will absorb MUCH more energy than the air, joule for joule, because air is nearly transparent to visible light, and the boiler is deliberately designed to absorb as much of it as possible. So while your source is technically correct, it's intentionally misleading. Nothing at all requires the air to be 4x the temperature of the water in the boiler, and in fact, it isn't going to be.

luxordelphi
I thought we had just established that in order for the water in the steam thing to get hot enough to provide power, the air has to get 4 times as hot. What do birds have to do with that?

Birds absorb a lot more energy from visible light than air does. And in fact, we have established that the air does not have to get 4 times as hot, and usually won't.

abecedarian
reply to post by luxordelphi

 

Go outside on a bright, summer day with an ambient temperature of around 95F.
What's hotter: the air outside or the asphalt parking lot?

To add, if the ground burns your feet but the air doesn't, which is hotter?

Or, go outside at noon on a bright summer day and put your cheek on a black car that's been in the sun all day. What's hotter, the air or your face?

Some air is going to be heated by Radiant heat from the collectors and it does not take much to start a updraft.

When you get the moist air of the Southwest Monsoon in the summer you will get lift of this moist air and under the right conditions have thunderstorms form above the solar plants.

You also have dust in the desert and the concentrated light from the reflectors hitting this dust is turned into heat.
the updraft of the heated air and dust is carries up and the dust will act as seed for raindrops.

I am waiting for a massive thunderstorm to take out the solar plant for days from wind. lighting, and hail.

reply to post by ANNED

When you get the moist air of the Southwest Monsoon in the summer you will get lift of this moist air and under the right conditions have thunderstorms form above the solar plants.

Around the towers a small volume of air will be warmed (not to 1000º). But that solar radiation would have heated the desert floor anyway (650 acres of it). There is no net increase in heat content, there is actually a loss because most of the radiation is being converted to electricity. But in any case, in comparison to the heat content/capacity of the entire region, it won't affect the monsoon.

But it does seem to fricassee some birds.

Phage
reply to post by ANNED

 

When you get the moist air of the Southwest Monsoon in the summer you will get lift of this moist air and under the right conditions have thunderstorms form above the solar plants.

Around the towers a small volume of air will be warmed (not to 1000º). But that solar radiation would have heated the desert floor anyway. There is no net increase in heat content, there is actually a loss because most of the radiation is being converted to electricity. But in any case, in comparison to the heat content/capacity of the entire region, it won't affect the monsoon.

But it does seem to fricassee some birds.

edit on 3/8/2014 by Phage because: (no reason given)

I will have to disagree. the desert floor absorbs heat and the mirrors reflect heat.
you would know if you worked in one of these solar plants. i have.
It only takes a couple degrees temperature increase to start a updraft
I have seen thunderstorms form just from brush fires in the desert.
I live out here in the Calif desert and know what goes on.
I have also built solar plants(SEGS plants) and worked on the Solar Two plant outside Barstow calif.
And i believe the solar trough type plants are better.
www.solaripedia.com...

reply to post by ANNED


Phage is 100% correct. Air is essentially transparent to the sunlight and is only minimally heated. The light does heat the tower because the tower absorbs light. So do birds, unfortunately for the birds.....

And yes, there is a net heat loss over the entire acreage due to the conversion to electricity which is transported away from the site.

This is just basic physics.