sendler2112
100 kW
Complete waste of engineering talent and resources. We have much better things we could be doing than to send 200 people to eventually die on Mars.cricketo said:
Wind and Solar vs Coal, Gasoline, Nuclear
- Thread starter Hillhater
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Hillhater
100 TW
Line losses are simple physics, and the parameters are well understood.cricketo said:
Underestimating them by several orders of magnitude, such that they significantly reduce the financial viability of the project, is a basic engineering error.
sendler2112
100 kW
cricketo said:
A complete selfish waste harkening back to our ingrained tribal competition. Sooner or later we must realize we are all stuck here together on one small planet and need to cooperate and act wisely.
Or they could stay here and die . . .sendler2112 said:
In any case, the BFR is going to replace the Falcon 9, and 99.99% of its launches will be commercial satellite and spacecraft launches, not Mars missions. And since it will be considerably cleaner (and more efficient for large launches, and more reusable) that's a good thing overall. For example, if solar power satellites are ever going to become a possibility, then something at _least_ as large as the BFR (now Super Heavy/Starship) will be essential.
sendler2112
100 kW
billvon said:
GigaWatt scale microwave energy transmission from orbit is somewhere between won't happen and can't happen. Much better to just put the panels on the ground and run wires.
If you say so.sendler2112 said:
IMO it is worth researching, since it solves the "no solar power at night" problem. With existing technology, solar power satellites could be launched via the BFR, and each one would generate ~100 megawatts. Current technology allows 1KW/20KG and designs on the drawing board can hit 1KW/1KG - and the BFR system can launch 100 metric tons into LEO at a time. With a predicted launch cost of $7 million, that means the satellite could cost $90 million and still be competitive with coal. China is planning to launch their first one in 2030.
sendler2112
100 kW
billvon said:
Generation is not the problem. Transmission is. This is an idea similar to inductive charging. Which seems really cool until you find out about the materials and losses involved. You immediately want to go right back to wires.
LeftieBiker
100 kW
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sendler2112 said:
This is where giant cables extending from anchors on the ground, right up to that geosynchronous solar power station in orbit, come in. Still in the science fiction stage, but definitely not impossible.
Which won't work in this case. A microwave link at 50% efficiency from orbit to Earth wins over an impossible wired link.sendler2112 said:
Look at it this way. Nuclear power plants are about 30% efficient, heat in to energy out. But we still use them.
sendler2112
100 kW
We have the rockets. We could try it. A GW orbiting farm needs a 1 km2 transmitter array. i wonder what the cross section and mass of the wires would be to carry a GW. The ground array is 10 km2. Would humans need to be there to assemble it?
sendler2112 said:
It is my understanding is that it's not possible to combine multiple smaller antennas to generate a more focused beam onto a smaller receiving antenna, but it is possible to combine multiple smaller antennas of equivalent size of a single antenna to produce the same amount of power onto a larger receiving antenna. In other words a bunch of smaller satellites can be deployed beaming onto the same receiving antenna, which would be much easier to implement than one giant satellite.
Hillhater
100 TW
Which, for cost reasons are only used for long distance , interstate type, transmissions , and are uneconomical for a typical state grid network.cricketo said:
Why engineer a grid for 100+ GW load peaks, when the required maximum load is only 20 GW ?
No, if the intermittent , high peak loads from , RE generators are the main cause , then they should be peanised until they install systems (storage?) to regulate and smooth the injection of power into the system.
Hillhater said:
Would be interesting to know what do you consider "cost reasons" in this case. There is nothing inherently expensive about DC transmission. DC has not been widely used due to difficulties and inefficiencies in voltage conversions, unlike AC. That was before solid-state devices were developed that make it easy and practical to work with DC. Now the only obstacle is the prevalence of AC systems, but when talking about new types of grids and power systems DC is a fair game.
Hillhater
100 TW
cricketo said:
A HVDC substation costs around 190 Million Euros as compared to a HV AC substation at around 60 Million Euros.
This is a reason why HVDC is usually reserved for distances over 1,600 kM. Or where coupling different frequency systems ( 50 and 60 Hz for example)
HVDC does reduce line losses by 4% or so. But is only cost effective at voltages of 500 kV to 1000 kV. Very expensive components at those voltages.
jonescg
100 MW
My prediction for 2050:
Australia will have a HVDC power line crossing the Nullarbor so that West Australian solar energy can be exported to the east coast during periods of high demand. Similarly, East coast solar power can prime WA with energy first thing in the morning.
We may even be exporting renewable energy to Indonesia and PNG by then...
Australia will have a HVDC power line crossing the Nullarbor so that West Australian solar energy can be exported to the east coast during periods of high demand. Similarly, East coast solar power can prime WA with energy first thing in the morning.
We may even be exporting renewable energy to Indonesia and PNG by then...
Not that it matters either way.sendler2112
100 kW
"In addition, when new energy sources supplanted pre-existing ones in the past, it was always because they proved to be “superior” to those in terms of energetic quality and productivity. Coal supplanted water, wind power and biomass because it proved to be a much more powerful, convenient and versatile source of energy. Petroleum then supplanted coal because it was superior still in terms of energy density, power density, fungibility, storability, transportability, ready availability, convenience and versatility of use. On all these aspects it does not appear that solar and wind energy may be in the same way “superior” to fossil fuels – but rather that they are in fact significantly “inferior”. The capture of diffuse and intermittent energy flows through man-made devices is, inherently, an imperfect substitute for the extraction and burning of concentrated energy locked up in fossil fuels. Unfortunately, no amount of “innovation” is fundamentally going to change that."
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https://www.resilience.org/stories/2019-03-21/a-modest-suggestion-for-the-worlds-climate-strikers/
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https://www.resilience.org/stories/2019-03-21/a-modest-suggestion-for-the-worlds-climate-strikers/
sendler2112
100 kW
"Here is how: in addition to your “climate strike”, or as a substitute to it if or when you get frustrated of being denied the kind of change you want, embark with all the strength and enthusiasm of your youth on an “energy diet”. A big, fat, relentless and endless energy diet. Not only on Fridays, but every single day of the week, 365 days per year, for the rest of your life.
Think about it this way: climate-wrecking fossil fuels only get supplied because there is huge and rising demand for them. And this demand, ultimately, comes from you, from me, from us. The vast majority of the things we do, each and every day, in each and every aspect of our lives, entails using fossil fuels, either in your country or on the other side of the world, or somewhere in between. For most of those things fossil fuels cannot be easily and quickly substituted by energy obtained from solar and wind flows. Therefore, just stop doing them, or at least reduce what you do to what is really necessary and useful."
Think about it this way: climate-wrecking fossil fuels only get supplied because there is huge and rising demand for them. And this demand, ultimately, comes from you, from me, from us. The vast majority of the things we do, each and every day, in each and every aspect of our lives, entails using fossil fuels, either in your country or on the other side of the world, or somewhere in between. For most of those things fossil fuels cannot be easily and quickly substituted by energy obtained from solar and wind flows. Therefore, just stop doing them, or at least reduce what you do to what is really necessary and useful."
And the only reason for the difference is semiconductor and control costs. The heavy metal (transformers, powerlines, breakers) are almost identical*.Hillhater said:
And semiconductors and controls are two things which, historically, come down _very_ fast.
Yep. And long distance transmission is a great way to start. Put in a line from Phoenix to Texas, so Phoenix can help Texas deal with its 7-8pm peak load. (Sun will still be up in Phoenix.) Then put one from Texas to Atlanta - same effect. Then as controllers/inverters/rectifiers get cheaper, put substations along the way to let smaller cities benefit as well.
(* - with breakers the big difference is going to be the big, well protected blowout magnets you'll need.)
sendler2112
100 kW
billvon said:
So thousands of rocket flights (to geostationary altitude?) to install super high tech 1GW. Wouldn't it just be much cheaper and less energetic to just install 4GW of cheap nameplate on the ground?
Well, in the example I gave, ten BFR launches to LEO, then a tug to get it out to geostationary orbit - that would give you 1GW.sendler2112 said:
If you could install that 4GW around the world and link them all with HVDC transmission - yes. But I don't know that that would be cheaper.
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