Slashdot Mirror
Will Renewable Energy Ever Meet All Our Energy Needs?
Lasrick writes "Dawn Stover has another great piece detailing why renewable energy will never provide us with all our energy needs. She deconstructs the unrealistic World Wildlife Fund report (co-written by several solar companies) that claims renewables will be able to provide 100% of the energy needs of several countries by 2050. From the article: 'When renewable energy experts get together, they tend to rhapsodize about the possibilities, believing that this will somehow inspire others to make their visions come true. But ambitious plans to power entire countries on solar energy (or wind or nuclear power, for that matter) don't have a snowball's chance in Australia. Such schemes are doomed to fail, and not because of the economic "reality" or the political "reality" -- however daunting those may be. They are doomed because of the physical reality: It's simply not physically possible for the world's human population to continue growing in numbers, affluence, and energy consumption without trashing the planet.'"
Until you define "needs", the question is pretty meaningless.
his article is sort of an IQ test: if you agree with him, you fail
for instance
quote "Take solar power.... In only one hour, the sun delivers as much energy to Earth's surface as humanity consumes in a year....astrophysicist Tom Murphy calculates that, even with an annual energy growth rate of only 2.3 percent, a civilization powered by solar energy would have to cover every square inch of Earth's land area with 100-percent-efficient solar panels within a few hundred years. "
I mean, do I really have to go thru all of hte problems with this one statement ?
'When renewable energy experts get together, they tend to rhapsodize about the possibilities, believing that this will somehow inspire others to make their visions come true.
Those aren't experts.
"First they came for the slanderers and i said nothing."
Yes. Fast forward far enough and we're either extinct or running off renewables. Non-renewables are temporary, pretty much by definition. Stupid question.
Without looking any deeper into your numbers, do you see nothing difficult about achieving a more than fourfold increase from 20% to 90% efficiency?
...on how you look at the problem.
Cover every roof in the United States with photovoltaics at today's efficiency levels and you'll generate roughly as much energy as the entire civilization consumes. And lots of places in the world have roofs other than just the United States....
But, though there's no problem with resource availability, there are two huge practical concerns. First, such a project would be massively expensive. Second, it generates electricity, which is not readily useable for transportation with today's infrastructure.
Neither of those problems are insurmountable. Though solar photovoltaics aren't cheap, they're not as expensive as many petrochemical alternatives being seriously considered, such as tar sands. That is, we might not be able to afford widespread PV adoption, true...but, if we can't afford it, we won't be able to afford anything else when the existing wells run dry.
(As a side note, we're already scraping the bottom of the oil barrel. Remember Deepwater Horizon? Imagine you're standing on the shore of the Colorado River in the middle of the Grand Canyon. A mile above you is the rim; that's how far below the ocean surface the wellhead was. Several miles above the rim is an airliner flying past. That's how far through solid rock the well was bored before it reached the oil deposits. That's how desperate we already are today for oil...loooooong gone are the days when you had to be careful in Texas with a pickaxe lest you start a gusher. Yes, we've got lots of oil left -- about half as much as the planet's total original reserves, in fact. But -- duh! -- we went for the easy-to-get-to, high-quality half first, and what's left increasingly fits the definition of, "dregs.")
The problem with transportation fuels is more pressing. At the very least, with enough input energy, you can extract CO2 from the atmosphere and turn it into fuel (via the Fischer-Tropsch process, for example) that you can put back into a tank to burn it again, so we have alternatives. The catch, of course, is that it takes a lot of excess energy to do so, and so won't be cheap.
TL/DR: Yes, we can run our society on solar power. No, it won't be cheap. No, we won't have any better alternatives. Yes, that means we're facing some tough times in the not-too-distant future.
Cheers,
b&
P.S. Even worse than the looming transportation fuel shortage is the looming petroleum-based fertilizer shortage. That double whammy is going to result in lots of people starving to death. b&
All but God can prove this sentence true.
Shh, he's on a roll.
---
ECHELON is a government program to find words like bomb, jihad, plutonium, assassinate, and anarchy.
This is a classic case of weighting down an opponent's thesis with extra assumptions, and then using those assumptions to shoot it down.
The basic question is, "is it possible to meet the world's current energy needs using renewables?"
The question the author is answering is, "is it possible to to meet the world's energy needs using renewables, assuming continued exponential growth forever?"
The answer to the second question is obviously "no", unless you're an economist. But the author only attacks the "exponential growth forever" idea, and says nothing about the first question, which is far more interesting.
A more accurate synopsis of her argument is this:
"Since population growth and per capita economic growth are dependent on ever-increasing energy consumption, it is physically impossible for renewable energy to provide an indefenite supply of unlimited energy. Therefore, demand reduction is the only really-long-term answer."
While I actually agree with this position, it's freaking worthless. First off, the author's argument and the WWF paper are speaking to entirely different time scales. It's functionally equivalent to saying we shouldn't waste time advocating the use of seat belts because they don't protect pedestrians. Scope matters!
The second and larger issue here is that her counter-argument is just as reality-deprived as she claims the WWF paper to be. In her conlcusion, she states simply, "To which I say: Why don't we just not do it?" i.e. why don't we exert self-control as a species and stop growing. Stop adding to total population. Stop increasing per capita consumption. It simply doesn't matter how true that is on paper. I find it amusing that she name checks the Do the Math blog which has been linked on Slashdot previously. The blog is compelling and well-written. It also avoids the flippant suggestion that converting to a zero-energy-growth global society will somehow be as obvious as a Nike commercial. The "reality check" is that the reckoning over energy consumption will be painful. Death and violence are in the cards long before equilibrium is reached. Human beings have the capacity to plan for the future and execute on those plans, but the number of years forward we are motivated to act upon have finite congnitive limits. The climate change issue is a recent-but-not-exclusive example of these limitations at work.
There is of course an amusing logical fallacy in her argument as a whole. If we are to ever reach the equilibrium she seeks, whether that is by design or through painful reaction, that equilibrium would have to be completely fueled by renewable resources, since we must eventually run out of the non-renewable ones. Doh!
Still, I'm glad this got posted to Slashdot. Undeneath her specific arguments there is a clear undercurrent. "Physicists are smarter than all the rest of you because we deal with real stuff so all of you can suck it." That kind of attitude definitely belongs here.
It's energy storage. Energy storage is the ultimate limiting factor on human civilization. Anyone that can crack the energy storage problem will be very, very wealthy.
Modern PV panels have a net positive energy budget over their lifetime.
It's not always been like that, but the current generation PV panels provide 5-7 times their energy cost (deployed in at 25-40 deg latitude)
That's much better than a lot of other renewable alternatives, like anything bio-.
It's also better than shale oil and tar sands, the energy requirements for extracting and refining that mess is huge.
The availability of the raw materials for PV is still an issue, and probably will be in the foreseeable future (unless there is a graphene-PV or non-rare-earth thin film PV breakthrough).
---- Sig. gone.
That "reality check" need a reality check on more than snowballs; example: http://en.wikipedia.org/wiki/Grid_parity
Most of the world is heading in a few more years to being able to make solar power more cheaply than getting power from the grid (the parts that are not already there, like much of India).
I'm all for living within our current energy means in a reasonable way (and I abhor the pollution from mining and burning coal and oil), but she cites a calculation that projects exponential growth on Earth forward a few hundred years, calculates we will need to cover the whole Earth in solar panels (and then the Galaxy), and then concludes from that somehow that we should stay the way we are. That just does not seem to be a healthy emotional space to be in.
She's probably against self-replicating space habitats that can duplicate themselves from sunlight and asteroidal ore, too? Even if it would mean quadrillions of people could live in the solar system and the survival of some aspect of humanity might be better assured? From the 1920s by J.D. Bernal on that:
http://vserver1.cscs.lsa.umich.edu/~crshalizi/Bernal/world/
Maybe we should all move back to live in trees in Africa? Or maybe that is too "advanced" compared to flopping around in muddy tidal flats?
There are always at least four issues to a resource question:
* How much stuff do we "want" based on cultural expectations?
* How efficiently can we use what we have to make what we want?
* How should we divide all that up?
* How can we expand the scope of what we are doing to new types or resources or new areas to find them in?
That is the complexity of the issue and she stakes out a position without discussing the possibilities or why she prefers one over the other. There might be a case to be made in the direction she tries to go (e.g. the Amish may have an overall happier community-oriented way of life), but she did not make it.
A 21st century issue: the irony of technologies of abundance in the hands of those still thinking in terms of scarcity.