EEVblog 1553 - World's First Commercial Solar Power Station

[EEVblog]

Dave visists the world's first commercial solar power station in White Cliffs, a small opal mining town in outback Australia.
Built in 1981 and using 14 heliostatic tracking 5m diameter dishes, this concentrated thermal solar plant produced 25kW of power using a steam generator.

[TimFox]

Before the price of PV came down to a reasonable value, it was assumed that practicable solar power would be concentrated solar flux heating the fluid in a heat engine.
There was some interest here in Chicago in a non-focusing concentrator that used an optical mirror similar to the eye of the American horseshoe crab (Limulus polyphemus), which has a multiple eye.
https://www.cambridge.org/core/journals/visual-neuroscience/article/abs/limuluseye-view-of-the-world/8C83786EEA811116B89B6B743351B71E
This would not need the tracking of the normal concentrator used in the Australian plant.

[EEVblog]

Before the price of PV came down to a reasonable value, it was assumed that practicable solar power would be concentrated solar flux heating the fluid in a heat engine.

Even in 1996 when they converted it to PV, the best option apparently was high temperature water cool PV cells at the focal point.

[nctnico]

Found any opal? 

[TimFox]

Before the price of PV came down to a reasonable value, it was assumed that practicable solar power would be concentrated solar flux heating the fluid in a heat engine.

Even in 1996 when they converted it to PV, the best option apparently was high temperature water cool PV cells at the focal point.

So long as you have operational solar concentration already installed, that makes perfect sense.
The heated water from the cell cooling could be used for other purposes as a side-benefit.

[thm_w]

So 62.5% of the energy goes into the steam, 360C, then steam generator efficiency was quoted around 20%.
Google shows numbers of 40-50% (63% maximum theoretical efficiency?). 

Probably still not worth it given the low cost of solar cells. I bet there is greater level of maintenance required here as well, compared to wiping down some solar panels.

Interesting to see this setup though.

[EEVblog]

Found any opal? 

We did!

[.RC.]

It is always amazing that while the rule of thumb seems to be 1kW/square metre of solar energy falls on the earth at peak times, converting that to a store-able and usable form of energy is just very inefficient and costly.

But 1kW/square metre is a lot of energy when you think about it.

[TimFox]

Since there is no monetary price for the incoming solar flux, the efficiency is not so important.
Capital expenditure and maintenance for the conversion and storage are the important factors.

[.RC.]

If the efficiency is crap you need lots of surface area though, and that costs money in buying and in maintenance, and in other ways like environmentally.

As an aside and so far off topic, but, I know the eevblog2 is not mentioned here, but I really enjoyed the shearing shed video. I have been on a couple of sheep properties, but that shed was massive. It would have been a hive of activity back in the day in the middle of shearing.

The au 1970's movie Sunday Too Far Away, was a movie showcasing the shearer in Australia back in the 1950's.

[TimFox]

"Buying and maintenance" -- that's what I said ("capital expenditure and maintenance").

[nctnico]

It is always amazing that while the rule of thumb seems to be 1kW/square metre of solar energy falls on the earth at peak times, converting that to a store-able and usable form of energy is just very inefficient and costly.

But 1kW/square metre is a lot of energy when you think about it.

For sure. When I'm in the sun and feel the heat on my skin, I can't help to think there is something seriously on fire up there in the sky. Mind boggling since I'm just the size of a tip of a super small needle compared to the distance between me and the sun.

[coppice]

It is always amazing that while the rule of thumb seems to be 1kW/square metre of solar energy falls on the earth at peak times, converting that to a store-able and usable form of energy is just very inefficient and costly.

But 1kW/square metre is a lot of energy when you think about it.

You start at 1kW per square metre. Then you have 15%-20% efficiency from the panels. Then you need to space them to get the angle to work well, unless you are close to the equator. Then you have to allow for their orientation only being optimal for a few hours each day. Then you have night. Then you have lower output in winter. Then you have bad weather. Finally you look at the average power over a whole year, and its a few watts per square metre of ground space. That sounds rather sad, but if you could suck a lot more out of that area, what would it do to the local climate to have such an energy black hole?

[TimFox]

Note that the intrinsic efficiency of silicon photovoltaic is from physics:  (< 1 A/W) x (< 1 V) is in the ballpark of 25%.
With respect to capital cost:  silicon is the most common element in the Earth's crust, so it is not in short supply.
Purification and processing of silica into high-grade silicon is one important cost, but it should improve in time.
Structure and aiming of the panels is another cost, perhaps subject to clever design.
Distribution is similar to distributing power from other sources.
Storage is progressing.
Never say never, but do the math.

[coppice]

Note that the intrinsic efficiency of silicon photovoltaic is from physics:  (< 1 A/W) x (< 1 V) is in the ballpark of 25%.

The efficiency is mostly about their bandwidth. The best panels capture a pretty good percentage of the frequencies they are sensitive to. Those near 40% solar cells that have been touted use a much more complex structure to be sensitive to a much wider range of frequencies. If you could make those cheap and reliable in high volume you'd have a real winner, but complex doesn't usually come cheap.

[EEVblog]

You start at 1kW per square metre. Then you have 15%-20% efficiency from the panels. Then you need to space them to get the angle to work well, unless you are close to the equator. Then you have to allow for their orientation only being optimal for a few hours each day. Then you have night. Then you have lower output in winter. Then you have bad weather. Finally you look at the average power over a whole year, and its a few watts per square metre of ground space. That sounds rather sad, but if you could suck a lot more out of that area, what would it do to the local climate to have such an energy black hole?

Sad?
You can power your entire house and an EV from panels on your roof. It's just a matter of initial captial outlay and your lifestyle.

[coppice]

You start at 1kW per square metre. Then you have 15%-20% efficiency from the panels. Then you need to space them to get the angle to work well, unless you are close to the equator. Then you have to allow for their orientation only being optimal for a few hours each day. Then you have night. Then you have lower output in winter. Then you have bad weather. Finally you look at the average power over a whole year, and its a few watts per square metre of ground space. That sounds rather sad, but if you could suck a lot more out of that area, what would it do to the local climate to have such an energy black hole?

Sad?
You can power your entire house and an EV from panels on your roof. It's just a matter of initial captial outlay and your lifestyle.

Try the videos on YouTube from David MacKay, expounding the content of "Without The Hot Air", which breaks down this stuff down for various energy sources, and look at the comments underneath. He is one of the very few people to try to explain the massive consequences of trying to make all energy production renewable. The comment are full of "he's an idiot" not because he is, but because the poster can't face the sad reality of a few watts per square metre.

[EEVblog]

Try the videos on YouTube from David MacKay, expounding the content of "Without The Hot Air", which breaks down this stuff down for various energy sources, and look at the comments underneath. He is one of the very few people to try to explain the massive consequences of trying to make all energy production renewable. The comment are full of "he's an idiot" not because he is, but because the poster can't face the sad reality of a few watts per square metre.

Who said anything about making all energy production renewable?

[coppice]

Try the videos on YouTube from David MacKay, expounding the content of "Without The Hot Air", which breaks down this stuff down for various energy sources, and look at the comments underneath. He is one of the very few people to try to explain the massive consequences of trying to make all energy production renewable. The comment are full of "he's an idiot" not because he is, but because the poster can't face the sad reality of a few watts per square metre.

Who said anything about making all energy production renewable?

That's the subject of the videos, but he includes solar. Just look at the comments. People find it really depressing that you only a few watts per square metre.

Haven't you read Without The Hot Air? I thought every engineer interested in renewable energy was familiar with it. Its really good. Its a few years old, and may need some updates, but it mostly still a solid analysis. David MacKay died, so the book is now in limbo.

[nctnico]

It is always amazing that while the rule of thumb seems to be 1kW/square metre of solar energy falls on the earth at peak times, converting that to a store-able and usable form of energy is just very inefficient and costly.

But 1kW/square metre is a lot of energy when you think about it.

You start at 1kW per square metre. Then you have 15%-20% efficiency from the panels. Then you need to space them to get the angle to work well, unless you are close to the equator. Then you have to allow for their orientation only being optimal for a few hours each day.

That is for sure. You need to be lucky to have a roof at the right angle to make optimum use of solar panels. Nobody ever considered need for a roof to face in the right direction and have a certain angle a few decades ago. And I doubt people consider this when building a new home nowadays.

[thm_w]

Try the videos on YouTube from David MacKay, expounding the content of "Without The Hot Air", which breaks down this stuff down for various energy sources, and look at the comments underneath. He is one of the very few people to try to explain the massive consequences of trying to make all energy production renewable. The comment are full of "he's an idiot" not because he is, but because the poster can't face the sad reality of a few watts per square metre.

https://en.wikipedia.org/wiki/Solar_power_in_Australia#/media/File:Australia_GHI_mid-size-map_156x171mm-300dpi_v20191205.png
We are talking about Australia, which gets a ton of sun, thats more than "a few watts."

He may have been right at the time of writing but now the numbers are out of date: https://www.carboncommentary.com/blog/2017/3/30/l6qcqgoedse1wmjjz87t09usoq6jva

[coppice]

Try the videos on YouTube from David MacKay, expounding the content of "Without The Hot Air", which breaks down this stuff down for various energy sources, and look at the comments underneath. He is one of the very few people to try to explain the massive consequences of trying to make all energy production renewable. The comment are full of "he's an idiot" not because he is, but because the poster can't face the sad reality of a few watts per square metre.

https://en.wikipedia.org/wiki/Solar_power_in_Australia#/media/File:Australia_GHI_mid-size-map_156x171mm-300dpi_v20191205.png
We are talking about Australia, which gets a ton of sun, thats more than "a few watts."

He may have been right at the time of writing but now the numbers are out of date: https://www.carboncommentary.com/blog/2017/3/30/l6qcqgoedse1wmjjz87t09usoq6jva

His numbers need some update, but they have not aged in any game changing way. Try looking at the real world figures for solar farms in hot countries. They take far more space than most people imagine.

[coppice]

It is always amazing that while the rule of thumb seems to be 1kW/square metre of solar energy falls on the earth at peak times, converting that to a store-able and usable form of energy is just very inefficient and costly.

But 1kW/square metre is a lot of energy when you think about it.

You start at 1kW per square metre. Then you have 15%-20% efficiency from the panels. Then you need to space them to get the angle to work well, unless you are close to the equator. Then you have to allow for their orientation only being optimal for a few hours each day.

That is for sure. You need to be lucky to have a roof at the right angle to make optimum use of solar panels. Nobody ever considered need for a roof to face in the right direction and have a certain angle a few decades ago. And I doubt people consider is when building a new home nowadays.

Its not just the orientation of the roof. Our roof is such an awkward shape I haven't seriously considered putting solar panels on it. Its so piecemeal, with slopes instead of gable ends.

[EEVblog]

His numbers need some update, but they have not aged in any game changing way. Try looking at the real world figures for solar farms in hot countries. They take far more space than most people imagine.

That does not mean that solar is stupid or not worthwhile. It is demonstrably worthwhile in many circumstances.
Again, who is talking about powering the entire world from solar power here? You seem to be the only one.

[nctnico]

It is always amazing that while the rule of thumb seems to be 1kW/square metre of solar energy falls on the earth at peak times, converting that to a store-able and usable form of energy is just very inefficient and costly.

But 1kW/square metre is a lot of energy when you think about it.

You start at 1kW per square metre. Then you have 15%-20% efficiency from the panels. Then you need to space them to get the angle to work well, unless you are close to the equator. Then you have to allow for their orientation only being optimal for a few hours each day.

That is for sure. You need to be lucky to have a roof at the right angle to make optimum use of solar panels. Nobody ever considered need for a roof to face in the right direction and have a certain angle a few decades ago. And I doubt people consider is when building a new home nowadays.

Its not just the orientation of the roof. Our roof is such an awkward shape I haven't seriously considered putting solar panels on it. Its so piecemeal, with slopes instead of gable ends.

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