Alternate Engineering: Victorian Solar Power

[Zor]

Would it be possible to build a viable thermo-solar power station (a bunch of mirrors pointed at a boiler driving a steam engine that powers a generator) using 1890s technology in Australia or India?


Zor

[Lord Revan]

depends on what you mean by viable IIRC the manufactoring tolerances for mirrors and generators weren't quite up to the level that modern plants use.

[Broomstick]

Yep. In fact, someone actually did it, but 30 years earlier than the date you mention. Let me introduce you to Monsieur Augustin Mouchot who built working solar-powered steam engines from the 1860's onward. In 1878 he had a working, solar-powered ice cube maker which he demonstrated at the Paris Universal Exhibition.

Regrettably, the French government deemed solar power as uneconomical (that isn't new, either) and cut off his research funds.

No reason the same couldn't be done in India or Australia in 1890.

[Lord Revan]

well for the long time solar powerplants (modern ones that is) had effciency rating of about 10% or so deeming one uneconomical "toy" isn't really that odd what works for low scale might not work for large scale after all.

[Purple]

You can't really blame the French for thinking like that either when this is what was required to make a couple of ice cubes.


Industrial grade power generator that is not.

[Broomstick]

Have you ever seen was the first steam engines looked like? They're like two or three stories tall and made of bricks and generate something like 1 horsepower. Why would an early solar engine being any less ridiculous? It takes time, money and research to produce a fully mature technology.

Anyhow, there's proof that it can and has been done. Not that it was elegant or efficient.

[Purple]

Have you ever seen was the first steam engines looked like? They're like two or three stories tall and made of bricks and generate something like 1 horsepower. Why would an early solar engine being any less ridiculous? It takes time, money and research to produce a fully mature technology.

Anyhow, there's proof that it can and has been done. Not that it was elegant or efficient.

All I am saying is that looking at it you can't blame the French for not seeing any potential in that.

[Lord Revan]

Have you ever seen was the first steam engines looked like? They're like two or three stories tall and made of bricks and generate something like 1 horsepower. Why would an early solar engine being any less ridiculous? It takes time, money and research to produce a fully mature technology.

Anyhow, there's proof that it can and has been done. Not that it was elegant or efficient.

True but Zor asked for a viable system not possible system, even today solar power is only borderline viable and mostly due to being green energy dispite being worse then fossil fuels in terms of energy production.

Could a system like be built sure but you'd still be better of using coal or oil to produce power.

[Simon_Jester]

Have you ever seen was the first steam engines looked like? They're like two or three stories tall and made of bricks and generate something like 1 horsepower. Why would an early solar engine being any less ridiculous? It takes time, money and research to produce a fully mature technology.

Anyhow, there's proof that it can and has been done. Not that it was elegant or efficient.

The first steam engines were ridiculously bulky and crude. With refinement they became far more effective... but the process of refining them took roughly a hundred years. You can ask "could steam engines have been invented in the early 1700s?" And the answer is they were, but by the time they became efficient enough to actually use for a diverse array of applications, it wasn't the 1700s anymore.

Likewise, could solar-based methods of generating electric power have been invented in the mid-1800s? They were, but by the time they became efficient enough to actually use seriously, it wasn't the 1800s anymore. The technology took many decades to become usable.

[Broomstick]

The chief thing that ended French research into solar power was a falling price for coal. If you have a situation where something like coal or oil is nonexistent or very rare then solar becomes more practical because there aren't cheaper alternatives that don't involve muscle power or massive, massive amounts of wood/charcoal.

So, let's return to the OP and make a hypothetical: steampunk tech in an Australia that is cut off from the rest of the world. Hypothetically, they either don't know about or can't (for whatever reason) extract the coal reserves. Heck, maybe it's post-apocalyptic and all the coal reserves were dug out by a prior civilization. Not a tremendous amount of woodland, but damn have they got all that sunny desert!.

Could they develop solar tech with Victorian levels of civilization? Yep, they could - the question is why would they bother? In our timeline they didn't because there were cheaper alternatives. It's that simple. If alternatives hadn't been cheaper history would have played out differently.

[Purple]

Would it? I mean, the technological leap between different types of steam engines is much less massive than the one between this thing and modern solar panels. So I am not saying that in such an alt world they would not have tried. But I doubt it would have gotten them very far.

[Simon_Jester]

The OP wasn't talking about photovoltaic solar panels, it was talking about solar-thermal power which is an entirely different principle.

Photovoltaics run at room temperature, with individual photons of sunlight hitting the panels and knocking individual electrons loose to create electric current.

Solar-thermal power works by using giant mirrors to concentrate sunlight into a small area to create heat, which creates steam, then you tap the steam with a turbine like you do with any other kind of electric power plant.

It's certainly possible to gradually develop solar thermal power into something you can use in an isolated Australia or whatever. The big problem is that doing this on a large scale requires industrial technology and machine tools. As a rule, you'd be better off using whatever power source you used to create the solar thermal plant, unless that involved, say, ten thousand men turning a capstan or something equally ridiculous.

[Raw Shark]

So, let's return to the OP and make a hypothetical: steampunk tech in an Australia that is cut off from the rest of the world. Hypothetically, they either don't know about or can't (for whatever reason) extract the coal reserves. Heck, maybe it's post-apocalyptic and all the coal reserves were dug out by a prior civilization. Not a tremendous amount of woodland, but damn have they got all that sunny desert!.

...and now I'm working on a screenplay for the steampunk version of Mad Max instead of doing my taxes.

[madd0ct0r]

Amother historic example:http://hiddencityphila.org/2014/05/fran ... ntury-ago/

In engineering terms let's see.
I would go for a long black pipe which carries water along a tube like parabolic mirror.
In that time period I would pay a man to watch a large bank of the machines, using a crank to adjust the angle of the parabolics as the sun moves. If the water available is saltwater and the land is desert, I might use the salt output as a glat crust on a scraped trough instead of expensive and fragile mirrors. Such a method might be used anyway as a preheater for the water. Less efficient and can maintain a smaller heat gradient of pipe vs air but effective.

If land is more expensive then I would probably go for a central pillar with big mirrors throwing light at the top. A crew of ground men would adjust the mirrors over the course of the day. The mirrors would be made of multiple pieces of flat sheet glass to get a few % more efficiency.

A final solution (ho ho) is to use swimming pools of very salty water. Left undisturbed the salt gradient is enough to trap warm water at the bottom. Use black ceramic tiles on the pool floor and drop a pipe loop connected to the steam engine in.

[Elheru Aran]

Perhaps this is just me drawing a blank, but I'm not sure how exactly you can translate a saltwater heater into steam? It doesn't get hot enough to create steam, surely?

And I am struck by the potential issue that these are largely going to be very stationary devices requiring a certain amount of geography. Not an issue in Australia or other open parts of the world, but these aren't going to really be an option anywhere you don't have open acreage unless you can build around the mirror setup. These devices also would not be particularly effective in areas without much regular sunlight as well, of course.

[Sea Skimmer]

That's a big problem, Europe and the US get lots of clouds, and if you cannot rely on this machine to power your factory it isn't very useful in the era of belt and shaft drives. You'll need a full power backup engine and boiler, and then why not run that all the time off cheap coal.Electrical equipment fed off a grid with interlinked power plants won't become common until the 1890s, but at that point hydro power and larger steam plants also radically improved.

If you were in Australia and had poor access to fuel an 1850s solar thermal plant might make sense, but it'd still be very expensive in both material and operating labor to implement. Also one might question what you would actually need to power in highly remote areas in that era. A water pumping system perhaps? That could also tolerate some intermediate outages.

[Starglider]

Have you ever seen was the first steam engines looked like? They're like two or three stories tall and made of bricks and generate something like 1 horsepower.

You can ask "could steam engines have been invented in the early 1700s?" And the answer is they were, but by the time they became efficient enough to actually use for a diverse array of applications, it wasn't the 1700s anymore.

Power output of early 1700s commercial steam engines was in the 10 to 20 hp range (more or less continuously, unlike animal power). No one would have bothered building them if they only produced 1hp.

[Simon_Jester]

True, at that point it'd be cheaper to buy a horse, and easier to take care of one.

That said, Broomstick may have been exaggerating; the basic point remains valid. The first steam engines were either commercially useless, or commercially useful for very specific applications and useless outside those applications. That state of affairs persisted for roughly 50-100 years.

Very early solar power (i.e. solar thermal in 1850) seems to have been in about the same state of development.

[Sea Skimmer]

1850 solar power would be more on par with the 100 AD aeolipile then the majesty that is a 1700 steam engine.

It isn't for no reason that most solar thermal plants even in the modern age have failed economically and been shut down, even when using fairly exotic working fluids like molten salt. While mirrors can create very high temperatures they cannot do so over a wide area of boiler surface area without utterly huge mirrors, which makes actually transmitting a high level of power a very difficult. The technology didn't exist in that era to exploit a very high point temperature (aka not all energy is equal, is the point), so you were far better off getting a lot of working fluid to a moderate temperature before pissing it into your shit engine. That pretty much lasted until the steam turbine was invented. Compounding and then triple expansion helped, but brought waves of new problems in the process concerning the entire device shaking apart from the huge moving masses which could never be exactly balanced.

As a point of just how bad this was, in the WW1 era the typical recyprocating steam locomotive was 6% efficient! Stationary engines could be better certainly, but often not radically so without going to a turbine layout.

Solar takes away your fuel cost, but everything else is a worse problem, and while labor was cheap it was never free. Solar really never has a chance if you don't have a computer to point the mirriors.

[Purple]

The main issue with all this is that in order to construct any of it you have to already have a functional metalworking industry. This means access to either wood or coal in sufficient quantities to make the system obsolete.

[Broomstick]

Unless your wood is running out and coal is either scare or hard to obtain... then it starts to make more sense.

[Elheru Aran]

The big issue with any solar technology in Europe is that much of it, *especially* the UK, simply doesn't have enough direct sunlight for solar technology to be practical, especially direct solar energy as opposed to solar electricity which IIRC can still function with clouds, just at a lessened efficiency.

With limited wood and coal resources, either they start the oil industry early, or you might see a uptick in wind energy at an earlier point. The Dutch already used it to a limited degree, so it's not like the technology wasn't out there. It might be possible to 'store' this energy by doing things like coiling boxes of massive springs, massive flywheels for centrifugal energy, and so forth.

[Sea Skimmer]

Wind was popular for the Dutch because Holland is very flat and located beside the ocean, so average wind speeds are decently high and somewhat reliable. And long term drainage of large areas and grinding grain were both tasks that didn't need to be done absolutely every single working day. Factories and mine pumps cannot operate on that basis.

The Dutch began building, or well, buying from the British, huge steam pumps for draining polders at a very early point too, so clearly wind power was not too satisfactory for them, no surprise given the blade size and bearing limitations they had. If you don't have a decent amount of wood and coal you simply aren't going to transition into a major industrial economy is the reality.