The Myth of Renewable Energy 835
Harperdog writes to this "Excellent piece by Dawn Stover about what renewables can and can't do. The sun and wind may be practically inexhaustible, but 'renewable' energy isn't. Solar, wind, and geothermal power are not fundamentally different from other energy technologies that consume finite natural resources. Good reading for anyone who thinks they know how to combat climate change."
Re:Renewable or infinite? (Score:5, Informative)
Quoth Homer of Simpson (Score:5, Informative)
Re:RTFA and reached a conclusion (Score:5, Informative)
In the 50+ years that they've been publishing I bet they're sick of talking about nuclear (power, weapons).
Source: Bulletin of the Atomic Scientists (Score:5, Informative)
Re:Renewable or infinite? (Score:5, Informative)
That's entirely dependent on current nuclear reactors (BWR, PWR, which all share the "water reactor" part in common). Molten salt reactors would need a lot less water.
Re:Renewable or infinite? (Score:5, Informative)
Unfortunately the article glosses over the fact that far more of those expensive and [s]potential[/s] actually hazardous materials are required to make carbon and nuclear based power generating stations. It also glosses over the lifespan of those products vs their counterparts (largely because no one bothers to collate the data on all the replacement parts that need to go into existing stations). The argument has never been that these solutions are perfect, nor infinite. The argument for green tech is that it's better overall and more sustainable than what we're currently doing.
Re:600 acre-feet, WHAT? (Score:4, Informative)
An acre-foot is a quite reasonable measure of volume if what you are interested in is collecting rain water in a place where land is sold by the acre and shallow depths remeasured in feet.
That said, I'd wholeheartedly vote for the US switching to metric measures if I had a vote.
Re:Renewable or infinite? (Score:5, Informative)
... they're still better over the lifetime of the vehicle. MIT: http://www.pacinst.org/topics/integrity_of_science/case_studies/hummer_vs_prius.pdf [pacinst.org]
Re:Renewable or infinite? (Score:5, Informative)
but if you calculate the amount they burnt to actually build them......
... then they still burn less. [renewableenergyworld.com]
Resources are recyclable, energy is not (Score:4, Informative)
If we burn coal, we still have carbon and oxygen just in a much lower energy state. We can't get that back without spending at least as much energy as we got out (in reality a lot more), which would defeat the whole point. Same with oil, gas and nuclear. So solar panels have a limited lifespan, but it's not like they disappear when they break down. Recycle them and make new ones, as long as you manage to get a net positive contribution of energy it's sustainable. The reason is of course that solar panels have an external power source while coal does not. Of course we have to design them to be recyclable and actually do it, but that's a matter of will and economics. But there's no way to do the same with fossil fuels, they'll never be sustainable because their energy is consumed.
Re:Renewable or infinite? (Score:3, Informative)
Actually, the Hummer comes out ahead ... so, the bias is exactly opposite to what you'd expect it to be.
The Hummer runs on bio-diesel I believe. That's the whole point of the poster, not that you compare a Hummer to a Prius and the Pruis is better.
What is the amount burnt to build coal plants? (Score:4, Informative)
For a given power generation capacity, there is no intrinsic reason why the energy cost for building windmills / solar cells should not be a fixed ratio of that of building coal plants. Maintenance costs for wind/solar are very low, but even if you don't believe me on this one, ask yourself, again, whether coal plants require no maintenance -- they do.
After that, solar/wind cost nothing in energy, while coal plants need to be fed coal, that also has to be transported.
A bit of truth for RE as pushed by big business (Score:4, Informative)
However, this deals with renewable energy as touted by big business. They make big huge systems that consume lots of resources so that they can sell them and make money. A passive solar house isn't going to use all these rare precious resources. Geothermal energy that is designed into the house going down 10 to 20 feet using convection isn't going to require the same massive resources that a huge power plant going hundreds of feet into the ground nor is there any fracking required. A personal wind turbine or hydro isn't going to need rare earth magnetics to squeeze out every drop of possible energy because energy use will already be reduced and you can just take the inefficiency of normal magnets/em into account when designing the system.
Besides the obvious slant of the article what we should realize is that large, centralized, hi tech renewable energy products are unsustainable. The way to go is smaller, decentralized, personal systems. Decentralization reduces the need for large quantities of any resource to be taken from any given area, making it sustainable. Is it a bother to have to wipe down your mirrors 2 or 3 times a year on your passive solar oil collection system, sure, but you won't need 600 acres of water in your back yard, just a damp cloth.
Unfortunately that involves designing tech that can be put together/serviced by your average joe and that simply isn't going to happen without government or industry help to educate the masses which won't happen because there's no money in teaching a man how to fish instead of selling him a fish everyday for the rest of his life.
Which is unfortunate. I'd love to see bamboo sand biofilm water filters with added activated carbon (provided by gov't/business) in homes for cleaning water instead of huge water treatment plants and plastic encased water filters that are non-renewable by the customer.(activated charcoal is renewable, if they let you get at it)
Re:Renewable or infinite? (Score:4, Informative)
My apologies .. the above is incorrect. I had assumed it was about the Hummers running on bio-diesel ... this is something else.
Re:Renewable or infinite? (Score:5, Informative)
Actually, it already has been a problem [guardian.co.uk]
and continues to be [oilprice.com]
Scale (Score:5, Informative)
The problem is not so much with the technologies' themselves as it is people's understanding of the scale of them. For example Tom Murphy [ucsd.edu] explains that dropping the great lakes by 1m would produce 54 billion kWh. Compare that to the 2,000 billion kWh produced every year by coal plants [wikipedia.org]. My napkin math says we would drain the great lakes of their current supply of water in the order of years, not decades just to replace coal.
Since the people on Slashdot are mathematically inclined, try to calculate the physical area needed for solar panels to replace a nuclear power station near you. To replace the Pickering Nuclear Planet [wikipedia.org] (3.1GW) the oldest planet here in Ontario with solar assuming Ontario get the global average amount of sun light [wikipedia.org] (which is pretty generous for Ontario) and gets an average of 20% efficiency you get 250W x 0.2 = 50W/m^2. So, (3.1E9W) / (50W/m^2) = 62E6 m^2 or 62,000 square km, a box 8km by 8km of solid solar panels or a circle with a radius of 4.4km. That is approx 2% the size of the exclusion zone around Chernobyl. We are talking about building something 2% the size of the area we fenced off during the worst nuclear accident in history per nuclear station.
Most renewable source of energy are not very concentrated, so anything dealing with them has to be huge, it's inescapable.
Re:What is the amount burnt to build coal plants? (Score:5, Informative)
I think that the point is that they all require maintenance, but that once started up, the solar and wind don't require mining, transportation of fuel, or environmental cleanup just by operating, while solar and wind just require machinery maintenance.
Re:Renewable or infinite? (Score:5, Informative)
You mean the battery in my Prius that's still going strong after five years? The Prius that has more cargo space than my old Jeep and can hold four people as opposed to the Jeep's two (four if you cut off two peoples' legs)? The Prius that gets me fifty miles to the gallon because I take the highway to and from work?
Have you even driven one? Hell, have you even SEEN one?
Re:Renewable or infinite? (Score:5, Informative)
1. Someone else wrote a paper called "Dust to dust" that claimed the lifetime energy cost of a Hummer was less than that of a Prius.
2. The "Hummer vs Prius" author disputes the "Dust to dust" paper's conclusions because they used arbitrary figures for lifetime mileage, energy used in manufacture, and so on.
3. The "Hummer vs Prius" author claims a quick recalculation shows the lifetime energy cost of a Prius is, indeed, lower than the Hummer.
Re:Renewable or infinite? (Score:5, Informative)
When the batteries fail on them, they will end up scrapped, no one will want a crappy economy car with a dead battery that doesn't even get good gas mileage anymore.
Early Priuses are now more than 10 years old and the batteries have hardly degraded. Looks like they don't need to be changed any more often than an engine in an internal combustion engine car.
http://news.consumerreports.org/cars/2011/02/200000-mile-toyota-prius-still-performs.html [consumerreports.org]
Note the average life of a car is about 13 years. The very first production Priuses are already older than that.
Re:Renewable or infinite? (Score:5, Informative)
That's one hell of a burden we are placing on our grand children.....
Re:Source: Bulletin of the Atomic Scientists (Score:5, Informative)
FAIL.
The Bulletin of Atomic Scientists is NOT a nuclear power advocacy group. It was founded by former Manhattan Project scientists as an anti-nuclear weapon advocacy group in 1945 in order to bring public attention to the dangers of nuclear arms.
They are probably most famous for the Doomsday Clock.
More recently the BAS has increasingly focused on explaining the dangers associated with nuclear power.
Here is a link to one of their publications:
http://books.google.com/books?id=ngYAAAAAMBAJ&printsec=frontcover&source=gbs_ge_summary_r&cad=0#v=onepage&q&f=true [google.com]
Re:Like magnets can't be re-used (Score:5, Informative)
Or for that matter that efficient generators ANYWHERE need rare earth magnets. In the end, almost all power generation needs the same kind of generator, the only difference is what makes them spin and how efficient you want them to be.
Large central station generators (actually alternators...) have been achieving 98 to 99% efficiency for several decades now using copper and electrical steel (no Neodymium). A larger rotor allows for more copper, which reduces the percentage of the alternators output power needed for generating the field. With a wind turbine sized alternator, the power required to maintain the field can approach 5% of the rated output, hence the use of permanent magnets (especially since the turbine is rarely producing rated output). Also note that making concrete for the foundations for the wind turbines does involve a lot of CO2 emissions - look up cement kilns.
FWIW, the NdFeB magnet material was originally developed at General Motors.
NOT an excellent article (Score:5, Informative)
It's a misleading hack piece. First, 600 acre-feet of water per year to run a 1000-MW plant is diddly-shit. For comparison, a unit-home consumes about 1kw (averaged over a month, give or take a factor of two) and one acre-foot/year of water. So a plant supplying enough power for a million homes, which themselves consume a million acre-feet/year of water, will add 600 acre-feet/yr of water to their consumption. Whoopie-shit.
Notice how no numbers were given for the geothermal plants and their consumption. The Geysers [wikipedia.org] were initially run from in-place groundwater, which they did consume (there was no condensation, no recharge). Now they are being recharged, NOT with groundwater, but with treated sewage water. So the article was misleading there, too, since groundwater is no longer the limiting factor.
She gives numbers for windpower resource consumption, but is again misleading. A "4-foot-wide, 7630 mile sidewalk". How do you suppose that compares to a single lane of interstate highway (12 feet wide) capable of carrying truck traffic? 636 miles of 4-lane interstate, NOT accounting for the increased road thickness. She repeats the "rare earth metals are rare" canard.
Neodymium [wikipedia.org]: "Although neodymium is classed as a "rare earth", it is no rarer than cobalt, nickel, and copper ore, and is widely distributed in the Earth's crust". She may be right about Dysprosium [wikipedia.org], at least with current magnet technology. It's not clear if it's necessary, or merely nice at current prices. Note that the current main consumption appears to be hybrid automobiles, not wind turbines. (Hybrid autos, not a good idea at present size.)
Her treatment of hydropower is similarly deceptive -- first dismiss newer technologies as "experimental", then hammer on the problems of (some) hydropower installations. Wave power [wikipedia.org] looks interesting. There's not too much that can go wrong with a buoy anchored to the bottom; we've got ample experience with them in their non-power-producing form.
All of the article lacks a good "compared to what" -- how much water and concrete are consumed by existing energy production? What resources do they consume?
So, NOT an excellent article.
Re:Renewable or infinite? (Score:4, Informative)
Re:Renewable or infinite? (Score:2, Informative)
"On the contrary, I would argue that the problem with nuclear power is that, as is becoming increasingly clear, people's fears about it are *justified*."
Nonsense. All significant accidents have happened in old (in some cases, 3 "generations" old) technology plants, and sometimes human error was a major component.
Newer designs are inherently safer. Chernobyl, for example, was a poorly-constructed plant using technology that was long outdated even when it was built. The majority of damage in Japan was caused by the improper storage of spent fuel right at the reactors -- areas that were neither designed nor safe for such storage.
Use newer technology (like molten-salt thorium reactors, for example), and you can virtually eliminate the problems that have plagued old nuclear plants, while protecting natural resources... we have plenty of thorium, for example. Thorium reactors are also -- or can be -- "breeder" reactors that produce more fuel than they consume. They can also be designed to eliminate the biggest causes of human error, making them that much safer still.
Re:Renewable or infinite? (Score:5, Informative)
Re:Renewable or infinite? (Score:5, Informative)
To be fair, the original Prius (Gen I - 2003 and older) batteries are starting to fail fairly regularly now that they're pretty old. But replacing them isn't that expensive - best bet is to replace the pack with a refurbished pack and send your old one back to the refurbisher to salvage the usable parts and recycle the rest. Many opt to refurb the pack with the cells from a Gen II (2004-2009) pack which are more robust and perform better.
Gen II Prius batteries are much more robust than the Gen I batteries - the occasional pack still fails here or there (usually because of a weak cell, not because the whole pack fails) but even then the best route is to replace the pack with a refurbished unit for half the price of a new pack.
There are shops that specialize in this (like Luscious Garage [lusciousgarage.com] - their blog has lots of info on what normally goes wrong in hybrids as well as how well they hold up under taxi use), though the best shops tend to be in locations where there is a high concentration of hybrid vehicles.
All that said - one doesn't need to worry about hybrid battery failure - in their best selling states (CARB states) the batteries are warranted for 10 years / 150k miles. You can be sure that the manufacturers have engineered them to hold up for at least that long - frequently replacing batteries that fail certainly isn't good for business.
Re:Renewable or infinite? (Score:2, Informative)
[Quote]you forget that nuclear generate nuclear waste that take thousand of years to read safer levels[/quote]
That's not an engineering problem though, that's a legal problem. With breeder reactors we could lower that from thousands of years to two or three hundred. Which is certainly still a significant amount of time, but hardly unmanageable.
Infornative? So ignorant that it's entertaining (Score:4, Informative)
The huge amounts of water required is a consequence of the advantage that nuclear power has over other forms of thermal power generation and you can't really use less without giving up that advantage. That advantage is the high temperatures and the large temperature difference that give you. That means a lot of cooling so you need a LOT of water available. That's really just a siting problem and only limits where you can put the reactors because the water isn't actually lost - just heated up. With a large river, lake or on the seashore the used cooling water can be released in such a way that it makes little difference.
Re:Renewable or infinite? (Score:3, Informative)
Your prius gets 50mpg? Well that's not bad, should I tell you that I just finished driving nearly 5000mi, in a '96 saturn and got around 49mpg on the highway. Yep, a car that's 15 years old, getting nearly the same performance.
I'm gonna go right ahead and call BS on that. It's not hard to look up EPA ratings even for old cars, and in 1996 Saturn sold nothing rated higher than 36mpg highway. EPA ratings don't always hit the mark spot on, but they aren't that bad.
GM sold only one car line during the 1990s with 40+ mpg EPA ratings: the Geo Metro. I used to drive one. I had the 1990 model year, EPA rated for 45mpg highway, and it really did hit that figure.
The way it got there was pretty easy to understand. The only tech which was "advanced" for 1990 was the use of electronic fuel injection and an engine computer which would turn a light on in the dash when you should shift up to save fuel. Everything else was just a matter of reducing power & drag, and cutting weight. It had a 3-cyl 1.0L 49hp engine, ultra narrow tires inflated to high pressure, a 1620 lb curb weight, and a very aerodynamic body (not quite so good as the Prius, but I don't think CFD design was being used for cars back then).
In later model years (including 1996) the fuel economy of the Metro actually dropped to about 40mpg highway, because they redesigned it to be slightly heavier with more creature comforts and upgraded it to a 1.3L 4-cyl engine with significantly more power. (Why? Gas was still cheap and people hated how gutless the 1.0L engine was.)
Saturns were significantly larger, heavier, and more powerful than Metros. The 1996 Saturn rated for 36 mpg had a 1.9L 4-cyl 100hp engine, a 2282 lb curb weight, and aerodynamics not quite so good as the Metro (hatchbacks and Kammbacks are the best body designs for aero). Saturns did not have some kind of revolutionary high efficiency engine, so there's no reason to believe they could've matched and exceeded Metros: too heavy, not aerodynamic enough, too big an engine.
Now before you go off on some asinine rant about how the Metro proves that the Prius is nothing special, the Prius is really in an entirely different league:
* It gets 50mpg in the city, not just on the highway.
* Curb weight of 3042 pounds (meaning: enough weight budget for real crumple zones, unlike tin cans such as my Metro)
* 98hp engine
* Lots of torque from the electric motor, so it's actually fairly zippy off the line
* Real creature comforts (those high fuel economy Metros were pretty spartan inside, to save weight)
* Isn't a cheap piece of shit (I loved my Metro, but I have no illusions!)
In other words, while you still have to make some sacrifices to get 50mpg, they're no longer anywhere near as stark as they were with the Metro, thanks to the hybrid drive system, and there's an entirely new capability that the Metro didn't have (high efficiency in stop-and-go traffic).