Slashdot Mirror
The Myth of Renewable Energy
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."
The argument being made is that expensive and potentially hazardous materials are required to make wind turbines and solar panels.
"In this house we obey the laws of thermodynamics!"
Damn_registrars has no butt-hole. Damn_registrars has no use for a butt-hole.
This is an article from The Bulletin of Atomic Scientists (http://en.wikipedia.org/wiki/Bulletin_of_the_Atomic_Scientists).
In the 50+ years that they've been publishing I bet they're sick of talking about nuclear (power, weapons).
Warning: This sig is not thread safe. For more information see Slashdot's sig policy.
Interesting that the summary doesn't mention that TFA is published in the Bulletin of the Atomic Scientists. Which is a quote respectable group; but nevertheless, they have a horse in the energy race, one that burns Uranium. TFA simply counts the cost of various "green" energies, but never compares them to the costs of "conventional", or nuclear, energy generation. You're left with the impression that "green" energy is a shill, that all forms of energy are equally bad, and so you might as well sit back and keep burning oil and coal until someone invents perpetual motion.
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.
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.
... 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
but if you calculate the amount they burnt to actually build them......
... then they still burn less.
Someone had to do it.
Actually, it already has been a problem
and continues to be
Someone had to do it.
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 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. 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 (3.1GW) the oldest planet here in Ontario with solar assuming Ontario get the global average amount of sun light (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.
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.
Do not look into laser with remaining eye.
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?
"I am an Adept of Tantric VAX."
The tl;dr on the Pacific Institute paper "Hummer vs Prius" is:
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.
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
Note the average life of a car is about 13 years. The very first production Priuses are already older than that.
The massive problem is the long term cost of decommissioning. I was at primary school when they started decommissioning my local nuclear plant. I'll be dead by the time they've finished.....
That's one hell of a burden we are placing on our grand children.....
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.
A Shadeless room is a brighter room.
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 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: "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, 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 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.
I'd rather have reactors that can't possibly melt down. we invented those over 25 years ago, but still use gen I and generation II designs which are inherently dangerous, need constant cooling for months even after shut down.
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 - 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.