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To store 1 megawatt-hour of electric energy as gravitational potential energy, you'd need to raise a 1000-metric-ton object 3.6 km into the air (assuming 100% conversion)
The highest man-made structure is ~830 m tall. The biggest heavy-duty cranes we have can lift a bit over 1000 metric tons (at least that's what I got from google).
So I think right now the technology to store energy as gravitational potential energy doesn't exist, at least economically. To get to the same point as the flywheels that have been tested you'd still need to go 900m high with a 1000-metric-ton object, which I'm not sure is possible (edit for clarity: I mean "possible with the technology we have right now")
Having good energy storage is good regardless of what type of electricity we're generating though, since it would help to prevent outages (in case of a emergency shutdown of some plant, for instance).
edit: Post below is correct, I'm off. It's 360m in the first part, 90m in the second. This is doable, though I'm not sure whether it's better than flywheels or what the costs would be.
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On August 06 2010 12:27 crate wrote:
To store 1 megawatt-hour of electric energy as gravitational potential energy, you'd need to raise a 1000-metric-ton object 3.6 km into the air (assuming 100% conversion)
Make that 360 meters kk.
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On August 06 2010 11:53 exeexe wrote:
But the 3 major power plants i had in mind was sun, water and wind, but there are proberbly more. If they combined cant fill out your demand for power then its your problem and not a problem for the technology.
World energy consumption is expected to surge, especially as the living conditions in developing countries improve in the next few decades. To put it quite simply, your options have many drawbacks, with the primary one being cost. Solar and wind are much more expensive than conventional options, nuclear included. Even worse, they're not really reliable - what happens when the sun goes down (Which it does on a daily basis) or the wind dies down? You can't ramp production up or down either, and electricity usage does vary seasonally and hourly. Energy storage requires additional infrastructure and costs. Even worse, if you're using something like solar that only produces electricity half the day, that means you need twice as much generating capacity as you would compared to something that works all the time (Well, not exactly since usage goes down at night, but you get the idea)
Hydro is actually a pretty economical option, but is sadly not without its environmental impacts. Not to mention you only have so many rivers you can dam. Not possible for it to form the backbone of power generation. Wind suffers from the same problem of limited geography. For that matter, so does solar.
I actually recently did a study on solar power, working off what is commercially available. The results were not encouraging. Generally speaking, today, without subsidies, a solar panel can barely expect to pay its own cost back in its lifetime - and this doesn't even include inflation. And this was done using one of the most sunny areas in the US.
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On August 06 2010 13:48 Underwhelmed wrote:
- what happens when the sun goes down (Which it does on a daily basis) or the wind dies down?
The sun never sets if you go west.
Source:
youtube.com
Go west where the sky is blue - is ofcourse a hint that it will never be night :D
On August 06 2010 13:48 Underwhelmed wrote:
I actually recently did a study on solar power, working off what is commercially available. The results were not encouraging. Generally speaking, today, without subsidies, a solar panel can barely expect to pay its own cost back in its lifetime - and this doesn't even include inflation. And this was done using one of the most sunny areas in the US.
We are talking about solving a problem of the interest of the society. Not planning the budget of the next year for a corporation. We are solving a problem, not earning money. So fuck the economics, thats a secondary objective.
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On August 06 2010 14:03 exeexe wrote:
We are talking about solving a problem of the interest of the society.
Society really doesn't want to pay ... how much? Five times as much maybe? I dunno, really; I've not looked in to the costs other than hearing from a lot of sources that solar is expensive. But society doesn't want to pay much more for its electricity. So if it's not economical, it's not going to happen.
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On August 06 2010 14:17 crate wrote:Show nested quote +On August 06 2010 14:03 exeexe wrote:
We are talking about solving a problem of the interest of the society. Society really doesn't want to pay ... how much? Five times as much maybe? I dunno, really; I've not looked in to the costs other than hearing from a lot of sources that solar is expensive. But society doesn't want to pay much more for its electricity. So if it's not economical, it's not going to happen.
I dont know, but i know your wars are expensive too and the society apperently wants to pay for that.
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On August 06 2010 14:03 exeexe wrote:The sun never sets if you go west. Source: youtube.comGo west where the sky is blue - is ofcourse a hint that it will never be night :D
Transmitting electricity across vast distances starts running into problems of inefficiency and infrastructure.
We are talking about solving a problem of the interest of the society. Not planning the budget of the next year for a corporation. We are solving a problem, not earning money. So fuck the economics, thats a secondary objective.
Don't be stupid. Money is always relevant because it's representative of costs involved and it doesn't pop out of nowhere. What is it going to cost society to solve this problem?
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On August 06 2010 05:05 {CC}StealthBlue wrote:
Debt, and Corruption is why this will never happen.
The idea that man is to blame for global warming is absurd enough.
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On August 06 2010 14:32 Underwhelmed wrote:
Transmitting electricity across vast distances starts running into problems of inefficiency and infrastructure.
Yeah but also the demand for electricity drops rampantly after the sun has set. Not in our society but in the future.
Don't be stupid. Money is always relevant because it's representative of costs involved and it doesn't pop out of nowhere. What is it going to cost society to solve this problem?
Rather you should ask what does it cost society if the problem will not be solved?
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On August 06 2010 14:40 exeexe wrote:
Yeah but also the demand for electricity drops rampantly after the sun has set. Not in our society but in the future.
I wish I had your confidence in predicting the future.
Rather you should ask what does it cost society if the problem will not be solved?
Along with "Of all potential solutions, which one has the least cost to society?". And this is why cost is very much relevant. It would be nice if in the future solar became cheap and efficient enough to replace nuclear, but I wouldn't bet the farm on it just yet. Of the options we have available right now, nuclear is the best.
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I would not mind trains at all, I visited Frankfurt a few weeks ago and didn't step inside a car once. I used public transportation 100% of the time, and it was efficient (just bought a train pass), fast, and there wasn't any garbage in the stations or in the cars. Very enjoyable, although I'm sure it must have a pretty high upkeep and cost a lot to establish. Does anyone know if it pay for itself through sales?
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On August 06 2010 12:27 crate wrote:
To store 1 megawatt-hour of electric energy as gravitational potential energy, you'd need to raise a 1000-metric-ton object 3.6 km into the air (assuming 100% conversion)
The highest man-made structure is ~830 m tall. The biggest heavy-duty cranes we have can lift a bit over 1000 metric tons (at least that's what I got from google).
So I think right now the technology to store energy as gravitational potential energy doesn't exist, at least economically. To get to the same point as the flywheels that have been tested you'd still need to go 900m high with a 1000-metric-ton object, which I'm not sure is possible (edit for clarity: I mean "possible with the technology we have right now")
Having good energy storage is good regardless of what type of electricity we're generating though, since it would help to prevent outages (in case of a emergency shutdown of some plant, for instance).
edit: Post below is correct, I'm off. It's 360m in the first part, 90m in the second. This is doable, though I'm not sure whether it's better than flywheels or what the costs would be.
This is actually ridiculously absurd for either number - the technology may exist, but I sincerely doubt it will be cost-effective. An average American household uses about 11 MWh a year, and there are some 110 million households in America right now (with both projected to grow, of course). That's about 1 billion MWh per month or so.
With the current technological constraints in place, that means we'd have to have 1 billion cranes lifting 1 billion compact cars to the height of approximately the Empire State Building to store energy.
I suppose we could construct this giant GPE-storage system in the middle of nowhere (i.e. Kansas) but would it really be worth it compared to our other options?
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On August 06 2010 12:13 crate wrote:Show nested quote +On August 06 2010 12:08 exeexe wrote:On August 06 2010 12:02 crate wrote:
In addition, solar and wind are highly variable (wind turbine output goes as the cube of the wind speed), and there is no way to store large amounts of energy on the grid, You know what i have always wondered why people continue to say this. Why cant we build towers whos job is to lift some heavy object up in the air. That will store energy and if we have energy in > energy out (of the entire grid) --> we raise the weight and energy out > energy in --> we lower the weight Just make enough of these towers and problem is solved. I'm not saying it's not possible, I'm saying we don't have it. There was some company working on flywheels to store energy (Rockwell mentioned it in his report), which is the same basic idea as your suggestion. They don't story very much energy (less than a megawatt-hour) and are costly. I don't think scaling this up to store the variable energy from a largely solar or wind system would be economical, but I'm not an expert. Regardless you will lose some energy in the process, you don't have 100% efficient engines. I don't know what the actual efficiency would be, but I think converting mechanical -> electrical (and vice-versa) is pretty efficient.
We're already using it in pumped storage power plants. It's just that instead of lifting solid weights, we lift water from a lower lake to an upper lake. The one I was working at last month produces 2.4GW (8*300MW) which is really noticeable, with about 80% efficiency. The civil engineering costs are huge but once you're done it can run forever and quite cheaply.
They weren't built as renewable energy sources backups (I don't think people really cared about this back then outside of commercial brochures), but rather as nuclear power plants backups (they don't like changing their power output), or plainly to make money (buy elecricity during off-peak hours, sell back during peak hours). But it would certainly work very well with renewable energy sources as well.
As many renewable energy sources as you can + nuclear reactors for the rest + PSPs (or whatever other storage solutions we have, but for now it's mostly PSPs) looks pretty solid to me. And by pretty solid I just mean better than anything fossil fuels can come up with right now.
Btw how can it take more time to travel by train than by car in the USA? Are the trains really slow or something? Highways' speed limits are pretty low in the USA so I thought the trains would rape cars easily. In France when I go back to my parents' home, it's either 2h00 by train (will be even faster after the high-speed railway is completed all the way), or 3h00-3h30 by car and you can't even sleep or read or do anything basically and you have a higher risk of getting yourself killed... it's a no-brainer really, especially since both cost about as much (high fuel prices + highway toll), unless you're like 4 people in the car.
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i take the train to school 
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On August 06 2010 16:13 d3_crescentia wrote:
An average American household uses about 11 MWh a year, and
Ofcourse you do -.-
+ Show Spoiler +
But could it not be lower? Just asking, no hints or anything. Just plain thoughts coming out of my head from out of nowehere.
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-Efficient use of waterways
-A system planned like the rail-system of European countries
-A prompt rail service with an excellent PR/Graphic design section to make it seem friendly, inviting, and modern. people in the US are suckers for that
-Jobs conveniently accessible by the railway
-Energy-efficient houses (properly sealed, halfway underground, uses sun energy to heat water/solar panels/both)
All of this is being done, which is a good thing and in San Francisco our public transit is one of the best I have ridden in the U.S. I do think it should be more popularized, not just the lower end communities taking it. I really dont even think it's HOW in this case as much as if people will drop their ego and get on a fucking bus.
BTW, my house is fully powered by solar energy by a great company that you rent the panels from and just pay them a monthly fee, they also install them for free. Only thing we had to pay for besides the monthly bill was an electrical service upgrade.
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The problem isn't neither technological nor economical. The only thing missing is political will.
Simple solutions exist and are working all around the globe. From better public transportation to better waste management. You only don't see more change because one side's lobbyists are richer than the other side's lobbyists.
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On August 06 2010 22:41 VIB wrote:
The problem isn't neither technological nor economical. The only thing missing is political will.
Simple solutions exist and are working all around the globe. From better public transportation to better waste management. You only don't see more change because one side's lobbyists are richer than the other side's lobbyists.
What's in for a politician to work on a project efficiently, when he can earn much more and have a better life working for lobbyists? Every single government project has to be at least overpaid to be built, compared to a market project, for the mere fact you're paying lousy bureaucratic overhead.
I'm more comfortable saying that it is primarily an economical problem, and that is the economic calculation problem.
Replacing economical interest by political interest is also a sub-par incentive solution to get things done. Political power, as tempting as it is, is best rewarding when it can be monetized. Few to no politicians are politicians for good will alone.
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On August 06 2010 06:21 TanGeng wrote:Show nested quote +On August 06 2010 05:49 Romantic wrote:
An inherent flaw in [b]capitalism!??[/b[ is that nobody takes into account systemic risk or non-$$$ considerations. Nobody thinks, "Oh when I buy this car taxes will go up to pay for the roads, I'll have to deal with congestion, global warming, drunk driving, noise pollution etc". America was purposefully marketed cars instead of more public transport and thats that. For a shitload of places it simply wouldn't be profitable.
Seriously, it's a flaw with only capitalism!? That's a limitation of the human mind. People in general don't think beyond, several steps. For cars, of concern are: how much does it costs, where and how can I use it, what are its dangers, what are its comforts. Drunk driving and traffic congestion is factored into the equation. Noise pollution is a function of where you live and work and people pay attention to that. One extra car on the road doesn't add much to the equation. What is left? A. Taxes will go up to pay for roads. Taxes were already leveed to pay for roads. Part of buying the car is a registration fee, which incidentally goes to pay for roads. B. Global Warming Exhaust pollution and smog might be an issue. Global warming is still unconvincing. C. America was purposefully marketed cars. America was purposefully helped into cars by its sprawling country. Ensenhower and the US interstate system helped along with that. Public transportation makes sense in the biggest cities. Destroy the suburbs and that'll destroy the need for most cars.
My dad does traffic forecasting, and the environmentalists are always trying to get him to manipulate the reports, to say that if we have dense housing and work that traffic will go down. This is downright incorrect. The more wealthy someone gets the more separated their home and workplace will be. IE not many people want to live in Oakland CA, but tons of corporate people work there. Also, mass transit isn't practical when traveling such distances. Also, the traffic in southern california is awful, but they won't let them put in more roads, as it is argued that this will increase traffic. The answer to this is yes, it will increase traffic marginally, but people will spend less time driving, hence actually improving gas mileage and decreasing CO2 output.
Also, these 'smart growth projects' aren't working, because few people want to live there, they are generally actually quite expensive, and even though they are near businesses and retail, there are other/better businesses retail centers nearby.
Also, high speed rail is a sham. It would have to be heavily subsidized, and although it is more environmentally friendly, SouthWest would be faster and cheaper...
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