New energy ideas

[Winston001]

Ocean posted this in the Climate thread and I think it is worthy of its own discussion:

The NZ government has fuck all resources. They have a little of the cash they've stolen from us left, but not enough uncommitted to social experiments to maintain the infrastructure we've got let alone get all inventive with new stuff. Nor do they have the tech personel resources to do it, they're all in Aus or Europe on a wee extended OE. We do have a few old bits of lab equipment kicking around CSIRO and a few other broom closets, will that do?

I could argue climate all day. Except I can't be fooked.
I can be fooked arguing energy, I think, maybe... is it time for my afternoon dram yet?

A little planning and basic engineering might produce solutions like the ones you suggest. I'm a great fan of massive overkill when it comes to engineering though, it's just a bunch of fun. Most of your suggestions have some unfortunate side effects too, but there's some that don't.

Wave generators do work, so far they just don't work on the scale we need without a bunch of difficult maintenance issues (hard to gat at). Seaborn windmills work well, self-regulating (they keel over in high wind), a mature, well understood technology. Just string a few tens of thousands of 'em off the south west coast. More efficient than land-bourn ones, and a bloody sight prettier, just need a fekin' big extension cord. Likely ecological impact: minimal. Cost of energy: high-ish. One problem with a similar scheme in the UK was that the air force put the kybosh on the development prototypes. Turns out their radar can't see past all dem rotating blades to where the ICBMs are. They did develop more radar-friendly ones from carbon fibre but by that time the budget was gone.

I wonder how many cubic kilometres of seawater flow through the Cook Straight twice every day? There's several metres difference in height either side of NZ for a fair bit of the day, we could partially dam that, bung in a shitload of turbines and walk away from energy shortage concerns for fekin ages. Ecological impact: slight. Cost of energy: not sure.

One for a few years time: How about we drill a hole about 5 - 6 Kilometres into some of the oceanic trenches that lurk off our eastern coast and bung a big superconducting cable down there. The thermal gradient is huge, and the cable maintains the same temperature throughout it's length, make steam, drive turbines. Ecological impact: zero. Cost of energy: depends on where the platform for the turbines is, probably competitive if they’re on the bottom.

Like any other ideas these all rely on one of the only two possible sources of energy available, internal tectonic sources (the moon is considered part of our system, although lunar tidal energy isn’t strictly internal it is similarly finite) and Solar (external). One estimate has enough solar energy falling on a few% of the planet’s surface at the equator to power every energy requirement we currently have (Fiji might do nicely). The energy contained in the thermal and kinetic tidal systems of the planet and it’s satellite are many orders of magnitude more than we’ll ever use before we shuffle off elsewhere. We just need to work on cost effective and ecologically clean ways to plug in.

Imagination is more important than knowledge, for knowledge is limited, whereas imagination embraces the entire world - stimulating progress, giving birth to evolution. - Albert Einstein

[davereid]

Some good ideas there Winston. I'm skeptical about land based windpower. I have had a nose around the windfarm at the Tararuas. Those massive machines only generate a peak of 1.6Mw, and an average of less than 400kw. Scumdogs V8 will make 400kw with just a tiny squirt of Nitrous..

And we don't know how much energy was used in their manufacture, transportation, or the on going cost of keeping them going.

Its possible that the old coal fired power station may not be as bad as it is painted !

One thing we can say for sure, is that wind power HAS been good for the environment. 'Cos its so damn expensive thats its helped push the retail price of electricity up.

[ManDownUnder]

I'm all for highly distributed generation.

Solar panels on the roof of every house, overflowing surpluses into the grid for storage, taking it back when needed. I personally prefer to use an approach where renewable energy sources are tapped (as opposed to a hole in the ground where the temperature gradient would work, albeit at the expense of storder thermal energy from the core).

While it's impact is incredibly minimal... mankind has a way of finding an ever expanding use for resources such that we'd be chilling the core of the Earth in a reduced timeframe and have yet ANOTHER problem to solve.
They ran Rotorua out of thermal energy by simply plugging houses into vents for heating...

Use the sun and all her artifacts. Plants grow, converting CO2 into cellulose which han be broken down into fuel products. Solar energy has a thermal component which should be used where possible (higher efficiency) or converted to power where needed.

Plop a 400W wind turbine onto the roof of new houses. Plop a thermal/solar hotwater heater up there too, and pay people to insulate their houses properly.

We CAN use what we've got, people just don't think to do it.

Fuel? What about catching rain, and cracking it (into H2 and O2) using solar powered electorolysis. We'd need a lot of it for sure... so... why not line roads with solar cells to do that too? Hells bells - the things might even keep the noise away from neighbouring houses.... a dual use!

But do we do it? No? Why? Profit to be made in exhausting existing hydrocarbon supplies...

[Hitcher]

Solar PV has much to commend it, apart from the cost. Australia, bless it, has set up a Solar Cities programme which involves public/private partnerships to facilitate uptake which, in the selected solar cities, has been impressive to date. The new "sliver" PV technology is brilliant, and is being widely uptaken as part of the Aussie initiative.

While Australia has taken a hammering from pro-Kyoto tree huggers for not signing the blessed protocol, that country is actually doing shitloads more to address climate change than many other governments that have signed. Good on them.

[davereid]

I'm not sure that P.V. solar panels are such a good idea. They use massive amounts of energy in their construction.

I had a reference which argured they will provide less energy during their viable lifetime than they took to manufacture. I'll keep looking for it and post it if I find it.

Additionally, they produce DC electricity, which can't be directly fed back into the grid. So extra devices are required to convert the dc output to AC, and at a voltage that is useful.

And batteries, once again made of rare metals, mined and refined using oil are required if the energy is to be stored.

But solar is a great source of energy. Good house design to maximise natural heating. Assistance from the sun to heat water is good too.

[Bass]

They ran Rotorua out of thermal energy by simply plugging houses into vents for heating...

.

Actually, no they didn't.
They ran out of geothermally heated water - the water ran out, not the heat. These days, reinjection largely sorts that out but is uneconomic on a 1 house domestic scale.
Ocean's suggestion still has merit, bloody difficult, (superconducting cables are hard to find, heat pipes might be better), but still has merit

[Ocean1]

Actually, no they didn't.
They ran out of geothermally heated water - the water ran out, not the heat. These days, reinjection largely sorts that out but is uneconomic on a 1 house domestic scale.
Ocean's suggestion still has merit, bloody difficult, (superconducting cables are hard to find, heat pipes might be better), but still has merit

It's not my idea dude, I stole it from... can't remember, Larry Niven?

And yes, the quantity of energy represented by geothermal sources is not limitless, but it's fucking near so.

The superconductor technology to do that isn't far away, and that's not an idle guess, if we fail to bake ourselves to a crisp within the next 20 years then superconductors capable of living in those temperatures will almost certainly be viable. The rest is old technology.

Think a little bigger. Marry that technology with balanced-orbit towers anchored near the equator and you get a generator. Not sure of output potential, I can't find clean data. It's not nescessarily a viable stand-alone energy project, but it is a cheap by-product of the almost-free inter-solar space flight the tower provides.

Oh, and I stole that one too.

[Finn]

I've built a small solar (100watts) system at home with 300Ah of deep cycle batteries and an inverter. I use this system when camping so I can watch Sky amongst other stuff. I'm starting to use it at home to calculate what I would need to be self sufficient. With me it's got nothing to do with power bills or saving the planet. I just like gadgets and there's something about being self sufficient.

The State of California gives huge kick backs for alternative energy and in most cases, people get a return on investment in about 12 months, sometimes less if you have over supply and sell it back to the grid. I wish our Government was this forward thinking.

[Ocean1]

The State of California gives huge kick backs for alternative energy and in most cases, people get a return on investment in about 12 months, sometimes less if you have over supply and sell it back to the grid. I wish our Government was this forward thinking.

They could start by requiring supply companies to buy-back up to 25% of a residential client's supply at full retail price. They actually spent a fair amount to install metres that won't work backwards exactly to avoid smart bastards like you pumping extrenal supply peak surplus back into the grid.

[Wolf]

Petrol powered power plant right next to the refinery - can supply electricity to the grid and also to the refinery to offset the electrical costs of refining it.

One fucking great finely-tuned engine (or a battery of engines) running constantly at optimum output to drive a fixed-load generator would be a lot more efficient than transporting petrol around the countryside in diesel-powered trucks and then burning it in a large number of variably tuned engines at varying outputs under varying loads.

The electricity pumped into the grid could then power electric vehicles - personal and public transport.

Strict emission management of the power plant (and more efficient burning of the fuel) would be an improvement over the emissions from all the aforementioned smaller engines.

Crude oil will still eventually run out but it will run out slower if used efficiently than it would the way it is being used at present.

Lots of things can be combusted and used to power generators - biofuels, diesel, oils, methane - some of which (like methane or ethanol produced from whey) are waste products and could be pressed into service to fuel power stations.

Oh Noes! Burning things, CO2-monster etc. CO2 is less of a "greenhouse gas" than methane. Burn nasty methane (sewerage treatment plants could become power stations), make less-nasty CO2, pass it through some serious scrubbers to render CO2 inert (an exhaust system that would bring a car to an abrupt halt from sheer weight).

Electric train systems (main trunk line, Wellington's "Unit"), electric trams (Wellington), and some of the new generation high-performance electric cars fitted with the latest and greatest batteries.

[Finn]

They actually spent a fair amount to install metres that won't work backwards exactly to avoid smart bastards like you pumping extrenal supply peak surplus back into the grid.

Didn't realise that. Bastards! So when I've got my full solar / turbine system with generator back up, they can have the bloody thing back. I'll even post it to them.

You seem very clued up on this stuff. Do you work in the industry?

[SpankMe]

More research money to find magnetic monopoles, or just chuck on nuclear power station on Stewart Island with a cable running directly to Auckland.

[Bass]

It's not my idea dude, I stole it from... can't remember, Larry Niven?

And yes, the quantity of energy represented by geothermal sources is not limitless, but it's fucking near so.

The superconductor technology to do that isn't far away, and that's not an idle guess, if we fail to bake ourselves to a crisp within the next 20 years then superconductors capable of living in those temperatures will almost certainly be viable. The rest is old technology.

Think a little bigger. Marry that technology with balanced-orbit towers anchored near the equator and you get a generator. Not sure of output potential, I can't find clean data. It's not nescessarily a viable stand-alone energy project, but it is a cheap by-product of the almost-free inter-solar space flight the tower provides.

Oh, and I stole that one too.

Yep, I realised all that.
You brought it to this forum though.
Science fiction has brought us some valuable stuff over the years - from nuclear subs (Jules Verne) to geostationary satellites (Arthur C Clarke as I recall) and it still continues.
The orbital towers don't make inter solar flight almost free but.
They get the atmosphere out of the equation, which surely reduces the cost big time. You still have the planet's gravity well to contend with.
However, with low orbit speeds circa 18,000 mph (pardon the units) and escape velocity at 24,000, the last 6000 is a whole heap easier to deal with than the first.
There are some serious physical issues with the towers but I can't remember exactly what. I think it has to do with the coriolis forces on an elevator ascending and descending. I THINK that when you calculate them they are high enough to require tower stiffening that is right on the edge of our materials technology.

[Ocean1]

Didn't realise that. Bastards! So when I've got my full solar / turbine system with generator back up, they can have the bloody thing back. I'll even post it to them.

You seem very clued up on this stuff. Do you work in the industry?

No. And I may be wrong, yours may well run arsy boo. Try it, turn everything off in the house and hook up a clean 230V supply to it, (NOT and extension cord from next door though eh?) the liddle wheels should go backwards.

Even if it works and they catch you they'll cause grief, they legally don't have to buy power from you. They wouldn't want the possible bad press from a simple refusal, but there'll be safety and systems compatibility concerns under duscussion, which is where industry regulation fits in...

[ManDownUnder]

I wish our Government was this forward thinking.

Ditto, but to be forward thinking it must first be thinking.... and they seem a bloody long way from that at times.

Buying votes is a good way to stay in power but a piss poor way of managing anything. Decisions made on the basis of the uneducated masses wanting the outcome/handout/promised BS nirvana.

edit: As a first step I quote like the idea of a switching supply so insensitive loads can cut from mains to solar/wind/locally generated power when it's available with enough ergs. Heating load seems a good place to start - Hot Water and the like.

[Steam]

There's no point in discussing any of this, other than to make you feel better about yourself.
China is opening a new coal-fired power station every FOUR DAYS.
And that's not one of these new-fangled high tech jobbies, they are the old style 1950's low-tech smoke-belching variety.
Till China cleans up its act there's just no point. We may as well open a couple of our own coal-fired power stations here, we have enough coal to last a thousand years at our current rate of consumption.
"Lead by example" you say? Ahahahaha, like they are paying any attention.

[ManDownUnder]

...turn everything off in the house and hook up a clean 230V supply to it, (NOT and extension cord from next door though eh?) the liddle wheels should go backwards.


I assume you mean a synchronised supply...?

[Finn]

Try it, turn everything off in the house and hook up a clean 230V supply to it, (NOT and extension cord from next door though eh?) the liddle wheels should go backwards.

Cool, I'll try it tonight. Thats the meter with the gas pipes connected to it right?

[ManDownUnder]

Cool, I'll try it tonight. Thats the meter with the gas pipes connected to it right?

LOL yeah!

... and Finn was never from again...

[Finn]

China is opening a new coal-fired power station every FOUR DAYS.

Excellent. My investment in coal mining should produce some good returns then.

It's bullshit by they way. One every 4 days. Hahahahahaha.

[Usarka]

solar energy is not the answer. look at the situation we are in after 100 years of consuming oil - its almost gone. we'd be nuts to do the same thing to the sun....

[avgas]

i think it should be compulsory for new housing developments to produce 20% of their power. Its not as expensive as people think.
How about this for an energy idea.....decrease consumption?
Too often i see shit that stirs me up, greenies complaining about stuff and not fixing it on their end.
Classic is Greenpeace HQ - lights on all the time, no sensor lights, no one around.
Un-insulated houses.
In-efficent designs.
Never mind free energy, if we cant look after energy we currently use.

[Ocean1]

The orbital towers don't make inter solar flight almost free but.
They get the atmosphere out of the equation, which surely reduces the cost big time.

You also get the Van Allen belt largely out of the equasion.

You still have the planet's gravity well to contend with.
However, with low orbit speeds circa 18,000 mph (pardon the units) and escape velocity at 24,000, the last 6000 is a whole heap easier to deal with than the first.

No you don't, the tower extends beyond geosync orbit, it has to, to stay in tension. That puts the top not only way past escape velocity but well into viable planetary cruise speeds. If you need to get anywhere further, (beyond "local" planets) you can make another completely disconnected tower, free-floating but spun end for end and synchronising every half turn with the fixed one. Possible velocity is limited only by the length of the secondary tower, which is liminted only by the tensile strength of the materials used to make it. If you need to go in another direction you just swing around the moon / Mars / Venus etc.
There are some serious physical issues with the towers but I can't remember exactly what. I think it has to do with the coriolis forces on an elevator ascending and descending. I THINK that when you calculate them they are high enough to require tower stiffening that is right on the edge of our materials technology.


Structural requirements are beyond arimid fibre technology, but by far less than an order of magnitude. Monofilliment carbon fibre would do, but at the moment we can only make that in zero gravity... chicken, egg. Bizzarly the only possible viable material on the planet is a particular spiderweb.

[Finn]

Too often i see shit that stirs me up, greenies complaining about stuff and not fixing it on their end.
Classic is Greenpeace HQ - lights on all the time, no sensor lights, no one around.
Un-insulated houses.
In-efficent designs.


True. I was tying up my boat at Westhaven a few years back and a team of professional protesters from Codpeace tuned up with 3 Ribs. They all had very old two stroke engines blowing more black smoke than Oprah Winfrey. I gave them an ear full I did.

[Ocean1]

I assume you mean a synchronised supply...?


Cool, I'll try it tonight. Thats the meter with the gas pipes connected to it right?


there'll be safety and systems compatibility concerns under duscussion

...........

[davereid]

Petrol powered power plant right next to the refinery - can supply electricity to the grid and also to the refinery to offset the electrical costs of refining it.

One fucking great finely-tuned engine (or a battery of engines) running constantly at optimum output to drive a fixed-load generator would be a lot more efficient than transporting petrol around the countryside in diesel-powered trucks and then burning it in a large number of variably tuned engines at varying outputs under varying loads.

The electricity pumped into the grid could then power electric vehicles - personal and public transport.

Strict emission management of the power plant (and more efficient burning of the fuel) would be an improvement over the emissions from all the aforementioned smaller engines.

Crude oil will still eventually run out but it will run out slower if used efficiently than it would the way it is being used at present.

Lots of things can be combusted and used to power generators - biofuels, diesel, oils, methane - some of which (like methane or ethanol produced from whey) are waste products and could be pressed into service to fuel power stations.

Oh Noes! Burning things, CO2-monster etc. CO2 is less of a "greenhouse gas" than methane. Burn nasty methane (sewerage treatment plants could become power stations), make less-nasty CO2, pass it through some serious scrubbers to render CO2 inert (an exhaust system that would bring a car to an abrupt halt from sheer weight).

Electric train systems (main trunk line, Wellington's "Unit"), electric trams (Wellington), and some of the new generation high-performance electric cars fitted with the latest and greatest batteries.

Yep, there are some very efficint prime movers out there. Have a look at
http://en.wikipedia.org/wiki/Wärtsilä-Sulzer_RTA96-C. at over 50% efficiency and http://www.gepower.com/prod_serv/products/gas_turbines_cc/en/h_system/index.htm at 60 %.

And if you use waste heat for heating homes etc, real efficiencies are even higher.

But power networks aren't much good.

Most networks run losses of between 7-10%.

About half of that is the powerline, losses at high voltage are about 3-4% per 1000km of line. The balance is lost at the lower voltage used to distribute power locally, and in the transformers that do the voltage change.

These figures are actually getting worse.

This is because overhead power lines have lower losses than buried cables. In a buried cable the conductors are very close to each other, and reactive losses become very significant.

We can distribute power using DC to help reduce some of these losses, but then we can't easily transform it back to AC - its an expensive and lossy operation.

So in fact, putting your power station near the load is generally the best idea if you can do it.

[ManDownUnder]

solar energy is not the answer. look at the situation we are in after 100 years of consuming oil - its almost gone. we'd be nuts to do the same thing to the sun....

LOL good point - me and my shortsighted ideas...

[Wolf]

Jerry Pournelle's "One Step Further Out" has ideas on "surviving with style" - solar arrays in geosynch orbit always in direct sunlight with no atmospheric interference, beaming power down to a receptor on Earth using a MASER (Microwave Amplification by Stimulated Emission of Radiation) - "clouds? what fucking clouds?". OK, any plane that overflies the area is toast but as Pournelle says: "call it 'evolution in action'".

Thermocouples - plenty of places with huge temperature differentials in reasonably close proximity - depths of ocean cf the surface, sink holes in geothermal areas etc. Every little bit helps.

[avgas]

They actually spent a fair amount to install metres that won't work backwards exactly to avoid smart bastards like you pumping extrenal supply peak surplus back into the grid.
Never mind the fact of harmonics and shit flushing back into the system when people do it wrong.

[Bass]

Structural requirements are beyond arimid fibre technology, but by far less than an order of magnitude. Monofilliment carbon fibre would do, but at the moment we can only make that in zero gravity... chicken, egg. Bizzarly the only possible viable material on the planet is a particular spiderweb.

Whoa!!!
Thats way taller than I was thinking! Lets see.....speed at earth surface at equator about 1000mph, radius about 4000 miles.
We want 24000 mph, so tower needs to be about 96,000 miles tall absolute minimum.


Consider this - if we are going to use the Earth's rotational momentum to fire off spaceships, if we do it enough, will we slow the Earth down? Sort of permanent daylight saving.

[Steam]

It's bullshit by they way. One every 4 days. Hahahahahaha.
I kid you not: From this BBC story (http://news.bbc.co.uk/2/hi/asia-pacific/6769743.stm)

China is now building about two power stations every week, the top climate change official at the UK Foreign Office, John Ashton, has said.



From the New York times (http://www.nytimes.com/2006/06/11/business/worldbusiness/11chinacoal.html?ex=1307678400en=e9ac1f6255a24fd8e i=5088partner=rssnytemc=rss&pagewanted=all) this story is from more than a year ago, since then things have accelerated.

Already, China uses more coal than the United States, the European Union and Japan combined. And it has increased coal consumption 14 percent in each of the past two years in the broadest industrialization ever. Every week to 10 days, another coal-fired power plant opens somewhere in China that is big enough to serve all the households in Dallas or San Diego.

[ManDownUnder]

Thermocouples - plenty of places with huge temperature differentials in reasonably close proximity - depths of ocean cf the surface, sink holes in geothermal areas etc. Every little bit helps.


Thermocouples? Ain't that just a techno word for hot sex?

[Wolf]

But power networks aren't much good.

Most networks run losses of between 7-10%.

About half of that is the powerline, losses at high voltage are about 3-4% per 1000km of line. The balance is lost at the lower voltage used to distribute power locally, and in the transformers that do the voltage change.
True, but what's the "power loss" (inefficiency) of the Toyota Prius that is burning petrol that was transported from Marsden Point to Wellington in a fucking great diesel-powered truck?

There are no "lossless" systems, but we could probably have a great play around with ways of lessening the total loss.

compare an electric car, a petrol-electric (or diesel-electric) hybrid and a petrol or diesel vehicle.

All are made up of lossy systems of varying degrees of efficiency and all rely on distribution of their source of energy which in turn relies on production of same.

going back through the chains:
electric car, power socket, electrical grid, power station (what else prior to that would depend on how that powerstation is powered and what mechanisms are in place to do so - e.g. Huntly relies on fucking great diesel trucks to haul coal; Arapuni relies on rainfall in the catchment area and gravity)

Hybrid or Internal combustion car, fuel pump, fuel tanker, fuel refinery, electrical grid, power station (for the electricity) ships, trucks, oil wells (for the crude oil) and, of course, the oil wells themselves rely on an electrical grid and a power station...

I think we need to get inventive about how we use the resources, find efficient means of doing things.

[Ocean1]

Whoa!!!
Thats way taller than I was thinking! Lets see.....speed at earth surface at equator about 1000mph, radius about 4000 miles.
We want 24000 mph, so tower needs to be about 96,000 miles tall absolute minimum.


Not quite, gravity is exponentially stronger the closer you get to the core of the masses involved, but centripetal force is more so with regards to angular velocity. Best way to picture the forces involved is to think about how you’d build it. Organise a stable geocentric platform, (look Ma, no hands…) somewhere over one of the more climatically stable parts of the equator. Start unreeling a small tracer cable up and down simultaneously, so that the tension is always balanced about your platform. Keep going until the one pointing at the planet touches, grab it and burry it in concrete. Wind the platform out a tad to keep the cable under a little tension. Start manufacturing a bigger cable, feeding it both ways along the tracer. When you get most of the way up / down tie a fucking big rock to the outwards end. Repeat. When you have a cable capable of taking a railcar stop.

What you’ve now got is basically a vertical bridge, with all the forces balanced lengthwise. It’s got a zero G station about 60% out along it’s length, at geocentric orbit, good place to set up manufacturing. You’ve got a 1G (upside down, but still 1G) station cruising out at the far end, doing just short of 2 x escape velocity. Glue a linear motor and a power cable to the side of the tower and organise some sort of energy recycler at the bottom. Make with that railcar on the linear motor and power up to the first stop, (geosync station), stop to admire the view. Drive out to the next stop, (the “ballast” rock), using a regenerative braking system all the way to replace, the energy you used getting to stop one.

From this point on the energy budget required to put a ton into orbit is the same as that to ship a ton across a similar distance on the surface. For the same price you can throw things off the top, or collect things passing by there.


Consider this - if we are going to use the Earth's rotational momentum to fire off spaceships, if we do it enough, will we slow the Earth down? Sort of permanent daylight saving.

Only up to the point where a significant portion of the planet's mass has been chucked. Want to take a shot at the energy required to do that? Also, seems likely that with such a device you'd be landing a lot of raw material from the asteroids at whatever velocities you need to balance that equation.

What would the view be like overhead from the second station?

[Wolf]

Bass and Ocean1. Either of you read Niven and Pournelle's "Barsoom Project" and/or "Descent of Anansi" (sp?)

Great SF around the logistics of space elevators and the construction thereof.

I doubt I'd live to see one built here or on Mars (Niven and Pournelle in at least one of their books had them building one on Mars as a test station - less gravity to worry about and if the cable breaks it's not going to wipe out a city falling to the ground).

The way things are going, I'm doubtful that my kids will live to see it.

Think its a great idea, though. Ultimate "Indian Rope Trick".

[Winston001]

Thanks for the great discussion folks. We seem to have split the topic as usual into alternative energy sources and space elevators. Arthur C Clarke wrote about a tether based in Sri Lanka in Fountains of Paradise.

There was a competition last year to build an elevator to assess engineering and materials. Anyway here is wikipedia article http://en.wikipedia.org/wiki/Space_elevator And another I just stumbled across http://science.nasa.gov/headlines/y2000/ast07sep_1.htm

Jerry Pournelle wrote his book on alternative energy more than 25 years ago (A Step Further Out) and I still haven't read anything in recent times to compare. And that is so frustrating - these ideas have been around (thermocline, geoenergy, ocean currents) for years but ignored by industry. The simple reason is oil is cheap. End of story.

The good news is that there is a research project running a turbine on the west coast of Wellington in the current running into Cook Strait - just as Ocean suggested. Magnitudes better than wind power. The downside is engineering - the marine environment is very challenging.

[Ocean1]

Bass and Ocean1. Either of you read Niven and Pournelle's "Barsoom Project" and/or "Descent of Anansi" (sp?)

Great SF around the logistics of space elevators and the construction thereof.

I doubt I'd live to see one built here or on Mars (Niven and Pournelle in at least one of their books had them building one on Mars as a test station - less gravity to worry about and if the cable breaks it's not going to wipe out a city falling to the ground).

The way things are going, I'm doubtful that my kids will live to see it.

Think its a great idea, though. Ultimate "Indian Rope Trick".


Barsoom Project? No, have read a lot of both though.

And you're right, the orbital tower/elevator was first suggested by a russian, in the mid 50's. It took much longer to develope the calculus to define such structures. Your reference reminded me, a lot of that work was developed by both professionals and complete ametures and mailed to Niven in response to "Ringworld". Simply amazing.

[Hitcher]

I have invented a perpetual motion device. All I need to do now is patent it. Undreamed of riches beckon!

[Ocean1]

And that is so frustrating - these ideas have been around (thermocline, geoenergy, ocean currents) for years but ignored by industry. The simple reason is oil is cheap. End of story.

And yet there was a time when we built the world's most advanced hydro-electric projects. The problem isn't the price of oil dude, artificial or otherwise, it's the lack of political balls. Even if we still had the tech resources we then did can you see any MMP contrived government supporting such long-term projects?

[davereid]

Yes, nature can build dams, and no fuss... but no way an energy company gets to do it !

[Wolf]

I have invented a perpetual motion device. All I need to do now is patent it. Undreamed of riches beckon!
You mean...

you've found a way to harness the energy poured into the "Scottish Thread"?

:not::not::not::not:

We're not worthy. We're not worthy...

[Jantar]

As an energy professional, I'm having a good giggle at this thread. Please keep it going until I return in 4 weeks time. :laugh:

[Ocean1]

As an energy professional, I'm having a good giggle at this thread. Please keep it going until I return in 4 weeks time. :laugh:

Don't fergit to turn yer KB off at the wall eh?

[Bass]

Not quite, gravity is exponentially stronger the closer you get to the core of the masses involved,

Inverse square law a la Sir Isaac and I used a linear relationship! Doh!



Only up to the point where a significant portion of the planet's mass has been chucked. Want to take a shot at the energy required to do that? Also, seems likely that with such a device you'd be landing a lot of raw material from the asteroids at whatever velocities you need to balance that equation.

What would the view be like overhead from the second station?

Two things: -
Firstly, surely conservation of energy says that the effect on the earth's rotational momentum is much greater than than the mass proportionality. After all, you are taking mass that is moving at some speed X at the surface and biffing it off at some much greater speed, into space.
I do agree even so, that you would have to chuck away an awful lot of mass before any effect was seen, although I wouldn't want to be in the neighbourhood when an energetic asteroid was landing.
Secondly, there is the issue of changing angular momentum. As your elevator climbs the tower, it is being accelerated in the direction of rotation and so exerts a force on the tower in the opposite direction. The opposite of course applies on the way down.
How do you tangentially stabilise the tower?
I guess that you could arrange that the effing big rock on the outer end is much more massive than the elevator, but then your cable has to be able to handle much more than just a railcar.

Still pretty cool but.

[ManDownUnder]

As an energy professional, I'm having a good giggle at this thread. Please keep it going until I return in 4 weeks time. :laugh:

You drink Red Bull and start calling yourself a what? (p/t)

[Ocean1]

Two things: -
Firstly, surely conservation of energy says that the effect on the earth's rotational momentum is much greater than than the mass proportionality.

You can blame Einstein this time, for the most famous equation of all time.

Secondly, there is the issue of changing angular momentum. As your elevator climbs the tower, it is being accelerated in the direction of rotation and so exerts a force on the tower in the opposite direction. The opposite of course applies on the way down.
How do you tangentially stabilise the tower?

How much lateral stiffening does a slingshot string need?



Think the largest sheer forces on such a structure would be atmospheric effects on the lower end and coriolis effects on the payload. Neither insignificant but both much smaller than the tensile stress on the structure. I did see a finite element analysis of such a tower somewhere, lateral acceleration hardly registered.

[Bass]

Think the largest sheer forces on such a structure would be atmospheric effects on the lower end and coriolis effects on the payload. Neither insignificant but both much smaller than the tensile stress on the structure. I did see a finite element analysis of such a tower somewhere, lateral acceleration hardly registered.

You're starting to lose me a bit here.

I can't see where E=MC squared is relevant. We are not talking about either relativistic speeds or matter-energy conversion. It's purely mechanics and Newtonian stuff at that

A slingshot needs huge stabilisation if the stone were to try and climb up the string from your hand to the pouch, which is the situation we have here.

The tangential accelerations I mentioned ARE the coriolis forces, I just used other words. I agree entirely about the tensile stress.
My point was that if your payload is a railcar, then your outer end anchor rock needs to be MUCH larger than the railcar to make the coriolis effects minor and so your cable needs to hold much more than just the railcar.

To use your analogy, this is equivalent to a slingshot with a large stone in the pouch and a smaller one climbing the string.

What am I missing?

Still an awesome scheme and your idea of running a superconductor up the tower as the cold end of some sort of heat engine........yeah!

[Ocean1]

You're starting to lose me a bit here.

I can't see where E=MC squared is relevant. We are not talking about either relativistic speeds or matter-energy conversion. It's purely mechanics and Newtonian stuff at that

It's perfectly relevant at sub relitivistic velocities, it's simply a discription of the amount of energy represented by a certain mass moving at a certain speed, relative to the observer. In this case the mass is the railcar and the observer is the tower, their relative velocities in both X and Y axis are identical. Their relative velocities in Z is a function of the rate of climb of the car, which you can control. I don't have the means to define it, but at any rational velocity corolias forces would be fairly minor wrt the overall structural requirements of the tower. It may be that the trip might take a day as opposed to an hour, in order to manage that but without hard numbers for the mass of each but I just don't know.

A slingshot needs huge stabilisation if the stone were to try and climb up the string from your hand to the pouch, which is the situation we have here.

The tangential accelerations I mentioned ARE the coriolis forces, I just used other words. I agree entirely about the tensile stress.
My point was that if your payload is a railcar, then your outer end anchor rock needs to be MUCH larger to make the coriolis effects minor and so your cable needs to hold much more than just the railcar.

To use your analogy, this is equivalent to a slingshot with a large stone in the pouch and a smaller one climbing the string.

Try it, put a bead on the string and hold it with your fingers, spin the string up and let the bead go. The string buckle any?

What am I missing?

Still an awesome scheme and your idea of running a superconductor up the tower as the cold end of some sort of heat engine........yeah!

More, given the planet's magnetic field it's basically a fucking huge generator, but I don't know how to figure output. Seems likely that at a minimum it'd power the elevator.

[Hitcher]

E=MC squared? I thought we were talking about F=gM1*M2/r squared.

[Swoop]

Plop a thermal/solar hotwater heater up there too...
The drawback with that is the simple fact that the solar panels and systems require maintenance.
The majority of kiwi houses fitted witht these are inefficient due to lack of maintenance.
A european systems engineer was over here and was horrified!
Our water quality was one contributing factor.

The suppliers of the equipment seem capable of the "quick sale" mentality, where they sell and install the gear, get the money out of the customer, and leave the customer feeling good... but uneducated about what needs doing in the future to maintain their investment.

[Bass]

Originally Posted by Bass
You're starting to lose me a bit here.

I can't see where E=MC squared is relevant. We are not talking about either relativistic speeds or matter-energy conversion. It's purely mechanics and Newtonian stuff at that

It's perfectly relevant at sub relitivistic velocities, it's simply a discription of the amount of energy represented by a certain mass moving at a certain speed, relative to the observer. In this case the mass is the railcar and the observer is the tower, their relative velocities in both X and Y axis are identical. Their relative velocities in Z is a function of the rate of climb of the car, which you can control. I don't have the means to define it, but at any rational velocity corolias forces would be fairly minor wrt the overall structural requirements of the tower. It may be that the trip might take a day as opposed to an hour, in order to manage that but without hard numbers for the mass of each but I just don't know.

OK.
I grant you that Maxwell's equations still work perfectly well at the sort of speeds we are talking about.
My point was that the relativistic effects would be tiny and that Mr Newton's stuff is perfectly adequate and WAY simpler. However, you are quite correct that a slow climb would reduce the coriolis effect.

A slingshot needs huge stabilisation if the stone were to try and climb up the string from your hand to the pouch, which is the situation we have here.

The tangential accelerations I mentioned ARE the coriolis forces, I just used other words. I agree entirely about the tensile stress.
My point was that if your payload is a railcar, then your outer end anchor rock needs to be MUCH larger to make the coriolis effects minor and so your cable needs to hold much more than just the railcar.

To use your analogy, this is equivalent to a slingshot with a large stone in the pouch and a smaller one climbing the string.

Try it, put a bead on the string and hold it with your fingers, spin the string up and let the bead go. The string buckle any?

But this is exactly my point - the string has to be strong enough to hold the rock - not the bead. Yes it does buckle due to coriolis forces and the amount of buckle depends on the ratio of the mass of the rock to the mass of the bead. Again to use your point, it also depends on how fast the bead moves,

What am I missing?

Still an awesome scheme and your idea of running a superconductor up the tower as the cold end of some sort of heat engine........yeah!



More, given the planet's magnetic field it's basically a fucking huge generator, but I don't know how to figure output. Seems likely that at a minimum it'd power the elevator.

Surely it rotates at the same speed as the earth and so is immobile relative to the earth's field - so no generation?


E=MC squared? I thought we were talking about F=gM1*M2/r squared.


I'm with you - also my point
That's Newton, not Einstein

[Ocean1]

Originally Posted by Bass
But this is exactly my point - the string has to be strong enough to hold the rock - not the bead. Yes it does buckle due to coriolis forces and the amount of buckle depends on the ratio of the mass of the rock to the mass of the bead. Again to use your point, it also depends on how fast the bead moves,


Arrrggg –ggg, me eyes is rupturing.

Why do you always make me go look, it disrupts the flow of my flippant and argumentative diatribe.

Here, numbers: http://en.wikipedia.org/wiki/Space_elevator#Angular_momentum.2C_speed_and_cable _lean

There’s that FEA diagram I saw too.

My point was that any structure capable of the vertical stress component orta be well good for the angular loads.

[ManDownUnder]

I came across a really simply idea the other day though.

Car pulls in from being out and the amount of heat slowly seeping off the bonnet was impressive. I lay some wet washing out on a towel and sure enough - water be gone!

It'd be nice to construct a duct of sorts to encourage the updraft, and hang washing in it. I reckon you'd dry most of a load per drive if that makes sense

[Bass]

Arrrggg –ggg, me eyes is rupturing.

Why do you always make me go look, it disrupts the flow of my flippant and argumentative diatribe.

Well, that's because I'm a pedantic SOB

Here, numbers: http://en.wikipedia.org/wiki/Space_elevator#Angular_momentum.2C_speed_and_cable _lean

There’s that FEA diagram I saw too.

What a cool article. Thanks for that

My point was that any structure capable of the vertical stress component orta be well good for the angular loads.

And I agree. It's just that the tension loads are a good deal higher than you first suggested


Besides, I enjoy a good technical bullshit session

[The Stranger]

Rather than solve a problem, why not remove it?
The company Sixpackback works for designs and prototypes electric motors. He was saying that they are able to make motors for refrigerators that are over 80% efficient when existing ones are around 20%.
They are FA dearer to produce as they use less copper and resources and are lighter.
How many other painless opportunities for energy saving are out there?

[avgas]

He was saying that they are able to make motors for refrigerators that are over 80% efficient when existing ones are around 20%.
Internal combustion fridge motors?
All electric motors run 50% or higher efficiency.
Unless its a really fucked one