Metal-Free 'Rhubarb' Battery Could Store Renewable Grid Energy 131
sciencehabit writes "A molecule nearly identical to one in rhubarb may hold the key to the future of renewable energy. Researchers have used the compound to create a high-performance 'flow' battery, a leading contender for storing renewable power in the electric utility grid. If the battery prototype can be scaled up, it could help utilities deliver renewable energy when the wind is calm and the sun isn't shining."
Abstract.
Be Bop a Re Bop (Score:1)
Just had to say it. Gotta love PHC!
Boris Johnson (Score:2)
is gonna love this [youtube.com].
Re:Rhubarb (Score:1)
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If I lost 100 lbs and got $100k in plastic surgery I could maybe be a model too!
...a model what?
( *poof!* - you're now plastic and at 1/144th scale )
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If I lost 100 lbs
You mean scaled down?
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Definitely. If he was scaled up he would be a fish.
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or a snake
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True. And snakes scale horizontally.
renewable energy only (Score:1)
That is a shame. I wish it could store non-renewable energy too...
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Technically, all energy is renewable, at least until we reach the heat death of the universe.
Sir, your comment lacks entropy
Re:If it can be scaled up? (Score:5, Interesting)
Yeah, go read what your own post actually says.
Bart Korman is the sponsor of House Bill 44 (HB44). The bill would allow Missouri utilities – including Ameren, Kansas City Power & Light, and Empire Electric Company – to count ancient hydroelectric plants like the 83 year-old Bagnell Dam towards compliance with the RES.
Clue: Hydro Power IS Renewable Power. Its perfectly appropriate.
In addition, HB44 would allow these utilities to purchase “renewable energy credits” from hydropower from anywhere in the world, of any size. If HB44 goes into law, utilities will change nothing about where their power comes from, and instead Missouri ratepayers would literally be subsidizing large hydropower from faraway places like the Hoover.
In the large picture, it doesn't matter where the power enters the GRID. We've been "wheeling" power for close to a hundred years.
There isn't wind power everywhere, so getting those areas that do have it to put it on the grid makes sense. If there is nobody living
in a a windy area, there would be little reason to build a wind farm there unless you could find remote purchasers.
Your example is seriously flawed. Your understanding of power generation is seriously lacking.
But I gotta say, your tinfoil hat is bright and shiny.
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Power companies are trying to op out of solar power subsidies.
Because the grid is not designed to handle significant amounts of unpredictable single phase power coming from residential customers, at inconvenient times of the day, and it is definitely not designed to pay retail rates for power from any source. Residential solar uptake in those areas is reaching the saturation point at which the grid simply cannot handle any more without a very serious overhaul, which includes pervasive bulk energy storage. They're fighting back against legislation that requires them
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Sounds like bullshit to me.
Grid condition is desired and planned. (Score:2, Interesting)
That's not false, but remember it's completely intentional. A well built network is overprovisioned, as /. readers know from personal experience, but the power grid is not currently well built because
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It's still not that insidious. Peak hours for power consumption and peak hours for solar output simply do not align, meaning you still need a whole lot of installed peak capacity to service the difference, or a whole lot of energy storage capacity. The fact that it is being used at a lower duty cycle means the capacity is now at a higher capital investment per MWh of usage.
The residential energy grid is simply not intended to handle upstream flow. The commercial grid is, absolutely. Power companies love
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Actually, I doubt even requiring residential solar to feed properly conditioned current upstream would ever be efficient or worth while.
Maybe they could feed the neighborhood loop, which is usually much lower voltage, but even this would probably a battery generator set in each house to supply 3-phase synced power back up to the transformer. Electronics sufficient to do that would probably be unsafe in the residence.
The thing that makes more sense is finding a solution for in-home storage such that each bu
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I doubt it.
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I think the reality is that "renewable" is a code word for many things to many people. To some it means local, to others it just means creating an economic incentive for cleaner power *somewhere*, as the credit system would.
For instance, I wouldn't support the allowance for hydroelectric power most of the time because of the tendency to screw up ecosystems more than some solar panels will, but it's still renewable.
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No doubt Hydro changes ecosystems, but unless you are damming very large rivers and endangering fish runs, the ecosystem changes are not significantly different than what was there, (larger lakes where smaller ones were).
The single most significant impact seems to be on certain species of ocean going fish.
As often as not fish and bird populations are improved by lakes forming upstream of dams.
The alleged damage is merely change, and not irreversible change, but some people won't accept any change.
They bitch
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Yeah, I'm not sure I'm ready to have cost issued decided by a judge.
In what may be the first time a U.S. solar power project has been declared cost-competitive against natural gas in a competitive bidding process, a judge has said solar is cheaper than natural gas. The ruling could be a road map for avoiding a new fossil fuel age dominated by big natural gas.
He can declare all he wants. When it comes to the issue of cost, a legal jurist is seriously outside his area of competence. Solar in Minnesota is asinine. I lived there for may years.
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The people who set it up just attached the panels vertically on poles.
Minnesota is tropical in comparison.
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Well, what this really means is that states such as Idaho and Kentucky can suddenly make it rich in renewable energy, as they're well positioned on the power grid. If other states are preventing renewable energy in-state, that just means other states can drop a few incentives and get a sudden boom in the local economy. Especially since all they need to do is become a storage pool for the existing grid.
Now renewable energy in privately-held consumables... that's another issue. Such states could easily bec
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I'm all for it, it seems that as these alternative power options become more feasible the more push back from corps you're likely to see, at least if you want them attached to the main grid.
Personally in sunny states I think every new house should have panels and be tied into the grid.
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Have you ever looked into how damaging it is to the environment to actually build a solar panel? They use nitrogen trifluoride to manufacture them.
Also, the batteries themselves, both production and recycling provide a large impact to the environment.
I lean more to nuclear technology, unfettered by the people who think that recycling spent fuel leads to weapons of doom.
And yes, I've lived with a braidwood nuclear power plant a few miles away and don't mind having a reactor in my back yard (the cooling lakes
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Well manufacturing can be done safely, not arguing it is, only that it is possible.
As for nukes, I'm all for it using newer technology, after all can you really run a city like Tokyo on solar?
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Stop spread FUD. The vast majority of solar cells are polycrystalline silicon. Nitrogen triflouride is only used for etching thin film solar cells, which requires only small amounts of the gas. In addition, flourine can be used directly, or the unused nitrogen triflouride can be captured.
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Now that they've leveled off their mountains [wikipedia.org], Kentucky and West Virginia have got plenty of flat land to build on!
What's the storage density? (Score:5, Interesting)
The summary implies that this technology could be used for large-scale power, but I wonder what the storage density is.
Specifically I wonder how this compares to liquid metal batteries [technologyreview.com]. If everything Professor Sadoway says about the liquid metal batteries is true, those really will provide grid-level storage of power.
Re:What's the storage density? (Score:4, Interesting)
The research paper is here: ma.ecsdl.org/content/MA2013-02/16/1688.full.pdf
There are some papers on liquid metal batteries here: www.ambri.com/.../Chemical_Reviews_LMB.pdf
The problem with any of these systems is that the cost of the raw materials themselves are subject to speculation by the currency markets and investment traders. So the minute, some magic energy storage chemical comes on the market, it is going to become as valuable as gold, and the manufacturing companies are going to be bought up and controlled.
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Sodium sulphur batteries have been deployed at grid scale in Japan. It's cheap and plentiful, and essay to recycle. Unlikely to be affected much by speculation.
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Actually neither the summary or the article state that it could be used large scale, they merely speculate.
Their test unit is no bigger than a toaster, and they haven't run it for very long.
They are just beginning their investigation.
One wonders if they are allowing for the amount of energy used to pump this stuff around in
their calculations, and the degree to which it is affected by temperature etc.
In short, there are one of these announcements appearing on Slashdot on an average of once
a month. There is
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Pumping a liquid around at a constant elevation doesn't have a very high energy cost. I imagine you'd lose far more energy through the round-trip chemical reactions than you would through pumping the liquid around.
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They are probably not including energy used to pump the liquids in their cycle efficiency. However, the volumetric energy density is quoted as exceeding 50Wh / L. A 5 watt water pump has a typical flow rate of ~300 L/h (maximum pumping height of 4 feet), resulting in an energy usage of ~0.017 Wh/L, which is less than 0.03% of the total energy density. So pumping should have little effect on the cycle efficiency.
It's not about density (Score:4, Informative)
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Storage density is only a problem for portable systems. For fixed storage installations, the important question is "what does it cost per ampere-hour of storage?" Inefficient storage that is cheap can beat highly efficient storage that is expensive.
Of course, to correctly calculate costs one needs to include things that are the result of storage density, like land acquisition and construction of holding tanks. But if the storage medium is cheap, it could come out ahead of some higher density system that
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The important figure of merit here is price per kWh of storage.
I agree. I asked about density because I assume that, if the energy density is low, that it will be prohibitively expensive. If a battery that can provide power to a city needs a city-sized tank of liquid, that would be expensive (in real estate cost if nothing else). But you are right, I don't actually care about the density, I care about whether this "pencils out" economically.
As long as it can provide grid-level power at a reasonable cost,
No eyebrows raised here (Score:2)
Wouldn't surprise me.
That stuff is extremely sour!
It's like eating pure H+
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Yeah; the use of battery has become almost as bad as the use of magazine....
We should just replace the word "battery" with "cluster" (as in beowulf) so that people understand what it means. But I think it's already too late for that.
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What's cluster go to do with hitting someone?
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Yeah; the use of battery has become almost as bad as the use of magazine
Um, I think you guys' pedantry is a bit misplaced here. 1.5 volt flashlight batteries all have only one cell, and they've called them "batteries" since electrical batteries were invented. In fact, the only battery I think I have that is more than one cell is the one in the smoke alarm. Websters says:
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1: You're quoting the MWD -- I can find all sorts of slang that it defines.
2: Battery has been used to refer to single cells for around 40 years, which is why I commented as I did -- "Magazine" has been in disuse even longer.
So basically, the words in common usage have shifted meaning so much that a) most people don't even know the original term anymore and b) it's now almost impossible to figure out what the word means by picking apart its components (a flashlight battery -- does it hurt?). Other words th
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[T]he only battery I think I have that is more than one cell is the one in the smoke alarm.
What about lead-acid car batteries? Or lithium batteries for your computer?
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You're right, I forgot about those.
Renewable? (Score:4, Funny)
Of course any attempt to store NON-Renewable energy will invalidate the warranty,
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Sort of like buckets of volatile hydrocarbons in a gizmo at home?
Sure it's also corrosive, but so is chlorine and everyone with a pool has that in their home too.
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I doubt the utilities would like this, but for the average home dweller with solar panels it would be useful.
Or we could use the battery in cars, so that while we charge our car in it's garage, when the sun goes down, it can power the house back the other way.
Which makes it really difficult to get to work the next morning.
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They don't even like the existing battery storage systems, because the energy companies are supposed to buy "surplus energy" back from home-owners. Their whole business model is based on being able to charge extra at peak times. If users are able to buy and store energy at night-rate times, they avoid the extra cost of day-time usage.
The Joker said- (Score:2, Funny)
More like a reversible fuel cell (Score:4, Informative)
EETimes has a more useful article. [eetimes.com] This is more like a reversible fuel cell. The working fluid is pumped through the cell, where a chemical reaction occurs. The process is reversible. So there's a "charged" fuel tank, a "discharged" fuel tank, pumps, and plumbing. No info yet on the energy density of the "charged" fuel tank, which is the big question.
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Actually there is a 'cathode reactant' tank and an 'anode reactant' tank. Within each tank, charged and discharged versions of the reactant are mixed. (This is shown in figure 1a of the paper: http://www.nature.com/nature/journal/v505/n7482/full/nature12909.html [nature.com] but that link will be pay-walled for most people.)
Some numbers from the paper (Score:5, Informative)
In the galvanic direction, peak power densities were 0.246Wcm2 and 0.600W cm2 at these same SOCs, respectively (Fig. 1c). To avoid significant water splitting in the electrolytic direction, we used a cut-off voltage of 1.5V, at which point the current densities observed at 10% and 90% SOCs were 2.25 A cm2 and 0.95Acm2, respectively, with corresponding power densities of 3.342Wcm2 and 1.414Wcm2. ...
The galvanic discharge capacity retention (that is, the number of coulombs extracted in one cycle divided by the number of coulombs extracted in the previous cycle) is above 99%, indicating the battery is capable of operating with minimal capacity fade and suggesting that current efficiencies are actually closer to 99%. ...
AQDS has an aqueous solubility greater than 1M at pH 0, and the quinone solution can thus be stored at relatively high energy density—volumetric and gravimetric energy densities exceed 50Whl1 and 50Whkg1, respectively. ...
As shown in Fig. 2, current efficiency starts at about 92% and climbs to about 95% over ~15 standard cycles. Note that these measurements are done near viable operating current densities for a battery of this kind. Because of this, we believe this number places an upper bound on the irreversible losses in the cell. In any case, 95% is comparable to values seen for other battery systems.
I'm not an expert in any applicable field, but as I have institutional access to the original paper, I scanned it to find what looked to me like relevant numbers. As I interpret the above:
It generates about 0.5W cm^-2 of membrane, so you'd need 2m^2 to get 1 kW output. (But presumably this can be in some compact folded/layered configuration.)
It can charge much faster than it discharges: that 2m^2 of membrane would let you charge at about 4kW.
The storage capacity of the battery fades at less than 1% per charge/discharge cycle.
One litre of reactants lets you store 50Wh of energy (i.e. 20kg for a kilowatt hour)
I think the last paragraph is saying that, neglecting pumping costs, it returns about 95% of the energy you put into it.
Note that we can expect these numbers to improve with further research, but whether there are big improvements to come or only minor ones I couldn't say.
Also: They use a two-reactant-tank set up rather than four tanks, so each tank holds a mixture of the 'charged' and 'discharged' forms of its reactants (e.g. one tank holds a mixture of Br2 and HBr.) I'd naively expected a four tank set up.
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One litre of reactants lets you store 50Wh of energy (i.e. 20kg for a kilowatt hour)
To put in in perspective, a random pick: the 1.4L engine of the current version of Volkswagen Golf (a city car, rather) generates 59kW - to power it up using the "rhubarb flow battery" and keep its performance unchanged (also assuming 100% efficiency of the power train), one would need about in excess of 100 liters of reactant per hour.
Me thinks:
* lotsa room for improvement
* even so, the more likely scenario for the next 10 years is the "renewable energy power plant buffering energy using flow batteries"
It's not for cars (Score:3)
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even so, the more likely scenario for the next 10 years is the "renewable energy power plant buffering energy using flow batteries" one rather than an "electric car filling its reactant tanks"
I have a 3.5 kW solar system on my roof that sells excess power back to the grid at 8c/kWh. At night, I pay 28c/kWh.
I use about 16kWh/day, around 40% of that at night. This flow battery takes around 20kg of reactant for a kilowatt hour, so I'd need around 120kg to meet current (ha) needs.
So, for my (probably not wildly atypical) situation, a battery like this would save me around $400/yr.
In other words, if you could produce these right now, with the power densities as stated, at a cost of $600 or les
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I use about 16kWh/day, around 40% of that at night. This flow battery takes around 20kg of reactant for a kilowatt hour, so I'd need around 120kg to meet current (ha) needs.
So, for my (probably not wildly atypical) situation, a battery like this would save me around $400/yr.
My (probably not wildly atypical situation): I'm differentially charged based on the hour of consumption: 30c/kWh off-peak, 38 (or 42) c/kWh (based on the total 3-month-based consumption) for peak.
It would make sense for me to suck power from the grid at night time and push it back in the grid during the day; it would make sense for the producers as well - can reduce their excess capacity they need to provision to deal with on-peak - this should worth something for them, even if considering only the mainte
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As compared to your bog standard lead acid battery, which contains approximately 94 WH per L and 48 Wh per kg. This thing is slightly better than lead acid by gravimetric energy density and about half as good by volumetric energy density.
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On the other hand, you can make this as big as you like without needing absurd amounts of lead - the energy is actually stored in the liquid, not on the anode or cathode. You can have Olympic swimming pool sized reservoirs (or even bigger), which is simply not practical for conventional batteries.
"A molecule nearly identical" (Score:2)
Is this what passes for science reporting... "A molecule nearly identical".
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I don't know why the focus is on rhubarb specifically. Anthraquinones are found all throughout nature, usually as some sort of red or yellow pigment (like the pigment carmine, for instance, made from cochineal insects). Rhubarb contains some compounds call anthraquinone glycosides, but I wouldn't characterize them as being "nearly identical" to anthraquinone disulfonic acid on account of sugar molecules not being very similar to sulfonic acid groups.
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That stuff is just shit. Sorry to just come out and say this, but I just wasted 5 minutes of my life, and about 50megs of bandwidth, finding that out so I could warn you guys about it!
You owe me $0.05. (Score:2)
I'm going to start demanding a nickle in response to every press release announcing a new miracle battery technology.
I figure that will let me retire in about 18 months.
G.
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In case you haven't noticed, you are not sitting around at night in a house illuminated by candles, kerosine, whale oil or burning gas. This is because inventing new useful technology is hard, and takes many trials over a extended period of time.
There are at least two startups with new technology battery systems installing units
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Bromine (Score:3)
Isn't anyone concerned that one of the reactants is a halogen?
Definitely associated with "flow" (Score:2)
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Definitely where the sun wasn't shining. Can't say that the wind was calm, though. OK, I think everybody's got the picture. I'll stop now.
A molecule nearly identical to... (Score:1)
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However, an additional oxygen molecule does give H2O2. You point stands.
Not a fan of utility scale electric storage (Score:4, Insightful)
I used to be a big advocate of the idea of having big batteries to store electricity from unreliable and "green" energy like wind and solar. That was until the cost of wind and solar power really sunk in. Wind power is on about par with peak energy generation like natural gas turbines, which is somewhere between 2x and 3x the cost of typical base load power like coal and nuclear. Solar power is so expensive, and variable (based on location, weather, usage, etc.) that it boggles my mind that any utility would even consider it. Then I recall all the subsidies from tax money spent on this nonsense that it starts to make sense to me again.
The cost of the wind and solar power is high enough that adding to the cost with storage has got to mean the total cost to the utility, and therefore the customer, would be something like 4x what coal and nuclear would cost. Then the size of these batteries would have to be astronomical.
One thing that concerns me is the environmental impact these batteries would have. The materials for the batteries would have to come from somewhere. I assume they would have to be mined out of the ground. These batteries would have to be manufactured, transported, etc. The carbon footprint of pouring the concrete pad these would most likely have to sit upon would have to be quite large.
Another question of environmental impact is, what if there is a leak? The stuff used in the batteries may have been derived from plant material but too much of anything can be bad. I grew up on a farm, I saw what too much water can do. I also saw what too much fertilizer can do, it burns the crops almost as if it was set on fire. What will the liquids in this battery do to crops and water supplies if there is an accidental release?
At least with nuclear power any radioactivity will decay away, with a chemical spill that stuff will always be there. I would much rather see someone come up with a technology to make the production of ammonia cheaper and not rely on natural gas. Ammonia is a fertilizer, a naturally occurring substance, and a fuel. An ammonia leak would still be an asphyxiation hazard, a fire hazard, could burn crops, and could pollute a water supply. However, ammonia is a gas that breaks down into nitrogen and water in the air. The stuff they use in this battery contains bromine and sulfur, what would that do to the water table?
No thanks, I'll take nuclear power instead.
Where's my flying car? (Score:2)
No you won't, because the banks and governments will not touch it and the energy utilities don't have enough ready cash to do it alone.
The lesson that should have been learnt after TMI of lots of small reactors didn't happen so the price per reactor is still far too high for it to happen without vast amounts of capital.
Also the nuclear lobby ate it's own children by lobbying against such small reactors and thorium research. Unless something comes out of India or
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No you won't, because the banks and governments will not touch it and the energy utilities don't have enough ready cash to do it alone.
You are absolutely correct. I'm thinking that the shift to nuclear power will not come from banks, governments, or utilities. Certainly some government involvement will be required, but only because current laws require that involvement. Government involvement is not inherent to building a nuclear power plant. I think that this infusion of cash for nuclear power will come from a private corporation that needs power for producing their product, not a corporation where power is the product.
I think that a
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Completely wrong, as seen globally where there are plenty of places where no such laws apply. The involvement is needed because private investors will not fund it. Large reactors with large capital costs and very long lead times before any return on the investment rule out anyone that is interested in getting their money back. Governments can afford to invest in things without a financial return in the decade the investment is made.
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Completely wrong, as seen globally where there are plenty of places where no such laws apply.
Where would that be? Every nation has laws on the handling of radioactive material. If there are any nations that do not have laws on radioactive materials then it's likely because they don't have enough infrastructure to be concerned about nuclear power. No one is going to build a nuclear power plant if there are no customers for the power, and no electrical grid to get it there.
I'm not advocating that there be no laws regulating nuclear material. I'm advocating sensible laws. In the USA the current r
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You know, there are remote places where it makes complete sense to install a bunch of solar panels instead of building a cable from nearest nuclear plant. There will be even more place like these if it becomes possible to store the generated power for later use, the longer the possible storing time the more sites become possible. Think between small battery packs and huge buildings. Storage sizes of small shacks.
The rest of your post is kinda funny. "At least with nuclear power any radioactivity will decay
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Your comment shows a common misunderstanding of radiation. You've heard the phrase, "A candle that burns twice as bright burns half as long." This phrase applies to radioactive materials. Anything that has a half life of thousands of years is not much of a radiation hazard, it's essentially inert. Anything that has a half-life of years is a massive hazard, but it's gone once it decays. A large portion of fission products have a half life of days, or even seconds, which is why being exposed to a reactor
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Sounds like you already have your mind set. You've got a very negative hypothetical here.
Then I'd also like to know how you derive the COST of Nuclear and Coal versus Solar and Wind. Keep in mind that "what we pay" isn't the full cost and WHERE we pay it is sometimes more important than HOW MUCH. Also - the cost of putting a solar panel at my house -- huge. But if a large company is using collectors to boil some water -- it's a much different cost per kilowatt.
For instance, a nuclear plant sucks in a lot of
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Solar collects energy when a utility is most likely going to experience peak demand -- well, at least in the summer.
This is false, the article in the summary even points this out. Once solar and wind reaches about 20% of total capacity it overwhelms the ability of the grid to compensate for peak load times.
Solar power peaks at noon, power consumption peaks at about 4:00PM. Something has to fill in that gap. If we use stored electricity for that then we are paying twice for our power, once to produce it, and again to store it. Barring some great leap in solar power technology we are going to be stuck with wind, coal,
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Solar radiation and bacteria may decompose organic chemicals but it does nothing for contamination from lead, mercury, cadmium, arsenic, etc. Weathering may wash these elements away and dilute them over time but then the same can be said for radioactive elements.
Any radioactive element that is a hazard to the human body must have a half-life less than a human half-life, otherwise the radioactive decay is unlikely to occur while the person is alive. The really bad fission products decay within seconds or d
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You can't complain about subsidies for wind and solar when every other energy source has been subsidized for decades.
Sure I can. I complain about all subsidies as the nature of subsidies is removing wealth from the profitable so that the wealth can be given to those that cannot produce that wealth on their own. Subsidies punish the productive and reward the unproductive.
If you want wind to prosper you need to get rid of the wind subsidies. Government subsidies require rules, there are always strings attached to that money. Strings that hold back any real development that might make it competitive. Right now wind pow
Speakin' of pies... (Score:5, Funny)
"Wow - a rhubarb pie? For me? Let me carve out a slice right now!"
"BZZZZERK!"
What's the power density of the battery ? (Score:1)
And how many charge/discharge cycle that "rhubarb battery" can handle ?
What are the benefits this "rhubarb battery" has over the ultra-capacitors which can handle huge number of rapid charge/discharge cycles ?
See the comment I posted back in 2012 regarding ultra-capacitors @ http://slashdot.org/comments.pl?sid=3143769&cid=41458249 [slashdot.org]
capacity higher than Duracell AAA (Score:2)
The difference is that a battery can hold a useful amount of energy.
As a rough guideline, 1 amp hour ~= 10,000 farads.
That's the capacity of a large ultra capacitor or a AAA battery. You don't power a city with those. You can, use them to power your SSD for four seconds in case of a power outage so it can finish writing the data.
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To be fair, there is talk about scaling them up to run electric cars.
No, the issue today with large ultracapacitors is that 1. tend to be experimental and 2. very expensive.
The advantage of doing something city size is you don't need to spend the extra cash on what ultracacitors are good at - small size and rapid discharge.
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The difference is that a battery can hold a useful amount of energy.
The difference is that this really isn't even a battery. It's a two-way fuel cell. The chemical reactor and energy storage parts are separate, allowing independent scaling of power output and storage capacity.