Wasn’t the main appeal of the mirror installations that you can store the heat somewhat efficiently? Rooftop solar is cost effective even here in Germany, where darkness and shadows loom around every corner.
I mean, if they’re dramatically cheaper, they don’t have to be efficient.
That being said, solar cells get around 20% efficiency, steam generators maybe 50% on a good day, subtract the reflection, collection and storage inefficiencies and you might get roughly in the same ballpark as solar cells.
Non-tracking solar panels are closer to 12% actual efficiency, 20% would be a theoretical efficiency. I only mention this because you used an actual efficiency estimate for the steam generator but not the solar panel.
These numbers change every year, but: solar panels on roofs don’t track so they’d be lucky to get 20%, average closer to 12%, efficiency and slowly degrade over a few years. Sun tracking panels can reach a maximum of around 40%, theoretically, but on average more like 20%-30%. You have to subtract the negative impact of creating and assembling the materials from it’s lifetime effectiveness, in Germany I believe Hydrogen Steel exists which is much greener than other types of smelting, or otherwise Aluminum is the higher grade material used for such things, and Photovoltaic Panels have a very specialized Glass in most cases that has to be exceptionally clear and strong. If the capacitance of the system is not enough to hold the produced power then an electrical failure will occur, so you must also include large commercial and industrial batteries.
Meanwhile, a Heliostat (a Collection Tower and Mirror Array) out in the desert has a theoretical efficiency just below 70%. Furthermore, if the capacity of the grid fills up then the array can be disable by adjusting the mirrors and excess power can be stored for extremely long periods of time by utilizing molten salt beneath the tower.
These efficiency numbers refer to how much of the heat energy from full spectrum light hitting the array is converted into electricity. Home panels are nice because you can put them on your home
If by “few” you mean like 30-50 then sure, they degrade. But it certainly beats anything with a spinning turbine. Or anything with moving parts really. PV is purely solid state physics, you can’t get more longevity than that.
If the capacitance of the system is not enough to hold the produced power then an electrical failure will occur, so you must also include large commercial and industrial batteries
That’s not true. You can also simply turn PV off. The inverters only run when they sense 50 Hz on their output terminals, it’s easy to have them turn off when it’s 50.2 instead. Basically all big powerplants follow that rule already, ordered by things like shutoff time etc.
a Heliostat (a Collection Tower and Mirror Array) out in the desert
Funny that you specified in the desert. The appeal of PV is not only that it’s cheap and easy, it also scales down to small investments and local power generation. If base load actually becomes a problem concentrated solar power will be relevant. But for now, slapping a few solar panels on your roof just makes sense.
My dad is still using the first 60w panel he bought in 1986, for 600$. Obvs added many more to his system, and who knows how efficient it is, but it does work, haven’t put a ampmeter on it though.
Mind you it was made in the USA, probably better materials than nowadays.
The mass market has really pushed solar panel production. I expect the material quality even of the cheap china panels to be better than what anyone was able to produce almost 40 years ago. That’s a long time to understand degradation processes and develop countermeasures.
Nobody was arguing anything otherwise, I was just answering questions about why we swap back to steam power for largescale. If you’re powering some LEDs and a Toaster then yeah it’s fine, if you’re powering 10,000 then heliostat time.
Cost per MWh is what tends to matter more than efficiency. Photovoltaics have become dirt cheap. Mirror collection systems haven’t been able to keep up, and the projects for them are basically defunct at this point.
Was worth trying, though. It wasn’t obvious that photovoltaics would get so damn cheap 10 or 20 years ago.
Right. We all know it’s generated by trees. It’s why cutting trees down is so bad for the environment, it stops the wind and everything gets more hot. Leading to global warming.
I like piezoelectrics and kinetic generators. The only two methods of generating electricity I know of that don’t involve steam other than solar panels.
At least, I think they’re different… Is a standard copper wire+magnet generator pizeoelectric? Or is it simply the operation is similar in that you generate electricity from moving things together? Like the difference between tiny little things in your shirt that generate electricity as you move around vs those flash lights you shake to charge.
Piezoelectric effect is when you vibrate certain crystals and they give off electricity. It’s also reversible. You can feed them electricity to generate sound. The beep-boop sound from small electronic devices is usually from a piezo speaker, because they’re dirt cheap.
You don’t get significant amounts of power out of it, though.
Also photovoltaic is reversible as well! Put light in get current out, put current in, get light out. But the diodes that get good light for the currents we use are shit for generating the current we like from the light we have and vice versa. Also! Most diodes are these types! That’s why we make their casing black, otherwise the light will interfere with computation!
Yeah. The one thing I ever saw that has me excited for a product that could exist, is that they can power a simple OLED display. And since an OLED display can be paper thin, they could put one in a t-shirt and you could have an animated design on your shirt instead of just a static picture. And that would be dope.
Of course, you’d need more than just the display, and i don’t think the little generators that can be sewn into a shirt would be enough to power the computing device that would be necessary to drive the animation for the display.
Some types of fusion can bypass steam generation and use what’s creatively called Direct Energy Conversion. If the fusion products are charged particles they can be passed through a magnetic field to separate them based on charge and collected onto plates. When you look at the electric potential between the plates you’ve effectively created a voltage, no steam necessary. It’s also theoretically possible to do the same with some types of fission products too.
There’s a whole bunch of mechanisms, largely depending on the fusion architecture and the atoms being fused. For tokamak reactors the circular nature lends itself well to what you describe, though usually it’s energy being imparted into the ions to keep them contained and away from the walls. In the ‘standard’ deuterium-tritium fusion model (the easiest to perform) fusion produces a helium nucleus and a neutron, where the neutron gets most of the energy. Since a neutron can’t be contained by magnets it impacts the chamber walls. This heat is wicked away by, you guessed it, cooling water which turns into steam. In order to use a direct energy conversion strategy you need a fusion reaction that produces no neutrons, but we’re not there yet.
my personal experience with this is that I was talking medication that made me nauseaus. Did I learn to not smoke when nauseaus? No, but I got a bucket now
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