At least according to Ray Kurzweil, author of The Singularity is Near and Fantastic Voyage
We will meet all of our energy needs with nano-engineered (engineered at the molecular scale) solar panels that are very efficient and inexpensive. We’ll need to capture only about 3 parts in 10,000 of the sunlight that falls on the Earth to meet all of our projected energy needs.
I have a hard time figuring out if Kurzweil is a complete kook or a genius. Singularity really blew me away, and I would love to believe the future he projects, but I am not making plans based on his views.
Ray Kurzweil may be a genius, but on this statement he made an order of magnitude error: We’ll need to capture only about 3 parts in 10,000 of the sunlight that falls on the Earth to meet all of our projected energy needs.
The correct number, I believe, is 20 parts in 10,000, according to DOE: So humans used the equivalent of less than 0.2% of the Sun’s energy striking the Earth’s surface in 1995..
Collecting 0.2% of the sun’s energy will prove a nice challenge, I am sure, but it hardly sounds impossible.
He’s a kooky genius.
He’s done a lot of outstanding work, no question, but he also frequently makes the mistake of assuming that current exponential trends can be extrapolated indefinitely.
On the other hand, I personally think that a “solar revolution”–installed solar power systems costing significantly less than current grid power–is perhaps 25% likely within the next decade. My bet would be on thin-film or dye-based technologies.
I personally, am not a believer in anyone who uses the word ‘nano’ as a buzzword in association with solar.
I have been slowly working on an article on nanotechnology, since that is the general area my Ph.D. project is in. The general rule is though, if you cannot mass produce something with excellent quality control repeatably, it’s going to remain in the lab. This is how you separate the charlatans from the legitimate advances.
The total global energy use in 1995 was 383 EJ. For comparison, about 5.5 million EJ of sunlight strikes the upper atmosphere of the Earth each year, and about 250,000 EJ of that makes it to Earth’s surface.
I don’t know what went wrong with the DOE’s calculator, but a lot more than 5% of solar energy hitting the atmosphere makes it to earth’s surface. I think it’s 75% under clear skies and more than 50% acccounting for clouds. DOE looks to be off by about 10x.
5.5m EJ sounds OK for upper atmosphere. Should be around 3m EJ for earth’s surface, putting human usage betwee 1-2 parts in 10,000 (sticking with Ray’s goofy units).
Of course only one fourth of the earth’s surface is land, and cheap PV is less than 10% efficient, so land usage is a lot higher than 1-2 parts in 10,000. On the other hand, electricity is high quality energy (e.g. a kWh of electricity moves a car 5x as far as a kWh of crude oil). Net/net I figure 20 acres out of 10,000, or 0.2% of our land area. We’ve got that much in roofs and probably that much again in road easements.
he also frequently makes the mistake of assuming that current exponential trends can be extrapolated indefinitely.
This is a common error among the techno-optimists. Witness the unwarranted enthusiasm around cellulosic ethanol.
This attitude is also endemic among the transhumanists (i.e. those who believe that the Singularity is coming in our lifetime). In fact, it might be their defining characteristic.
Once, I was myself a techno-optimist bordering on a transhumanist. But if I have learned anything from my engineering experience, it is that execution in the real-world is messy, inefficient, rarely works as well it did on paper, and requires maintenance that is often deferred. This last point is probably the single biggest reason (even more than limited energy resources) why I am skeptical of the transhumanist vision: it relies on increasingly complex technology which must function consistently and correctly. But as we all know, humans are better at building new toys than they are are maintaining the ones they have (see the recent ASCE report on America’s infrastructure). We’re already very much behind the curve. I very much doubt we can sustain the level of ubiquitous complex high technology required to see us through the Singularity.
I don’t know what went wrong with the DOE’s calculator, but a lot more than 5% of solar energy hitting the atmosphere makes it to earth’s surface. I think it’s 75% under clear skies and more than 50% acccounting for clouds. DOE looks to be off by about 10x.
Interesting comment, doggy, but I suspect DOE is on top of this. As explained by Wikipedia:
The average albedo (reflectivity) of the Earth is about 0.3, which means that 30% of the incident solar energy is reflected back into space, while 70% is absorbed by the Earth and reradiated as infrared.[Corresponding roughly to the 75% you cite. However…] …The remaining 70% of the incident energy is absorbed:
51% absorbed by land and water, then emerging in the following ways:
-23% transferred back into the atmosphere as latent heat by the evaporation of water
-7% transferred back into the atmosphere by heated rising air
-6% radiated directly into space
-15% transferred into the atmosphere by radiation, then reradiated into space
19% absorbed by the atmosphere and clouds, including:
-16% reradiated back into space
-3% transferred to clouds, from where it is radiated back into space
When the Earth is at thermal equilibrium, the same 70% that is absorbed is reradiated:
64% by the clouds and atmosphere
6% by the ground
The DOE number corresponds to the last number, which seems like a good conslusion. You don’t have access to the energy absorbed by the clouds and atmosphere.
Optimist, read it again:
30% of the incident solar energy is reflected back into space, while 70% is absorbed by the Earth……
The 70% absorbed by the earth breaks down as:
51% absorbed by land and water,…..
19% absorbed by the atmosphere and clouds,…..
The 19% does not hit the solar panels but that 51% does. Transfer of solar energy from the ground back into the atmosphere is irrelevant for the case of solar panels, which intercept the photons before they make it to the ground.
Plenty of energy out there to be had.
http://greyfalcon.net/greenenergy.png
But frankly so far the best looking solar technology is solar thermal.
http://blogs.business2.com/greenwombat/2007/09/solar-startup-a.html
Thinfilm PV comes up second.
http://greyfalcon.net/pv
Hey guys, read today’s energy blog. PG&E and FP&L have announced a new solar power plant they say will compete with conventional power plants in terms of price.
This may be big news. RR has already suggested that solar power is abundant enough and clean enough to juice our elelctrical grid, while we cross over to PHEVs.
I think both technologies (solar and PHEVs) are very close to commercial. Certainly, if the price mechanism could capture external costs – wars, pollution, a standing military costing $750 billion a year – solar energy is very serious option.
As to Green Engineer: I think not only optimists, but doomsters extrapolate to reach their goals.
Look at worldwide fossil crude consumption. In doomster models, it grows by 2.2 percent annually compounded, meaning it doubles in roughly 35 years, an then we run out suddenly, or somewhere along the way.
In reality, higher prices dampen demand – we may have hit Peak Demand already, and I predict flat to no growth going forward, if oil stays at more than $60 a barrel.
At no growth, we get extra decades, maybe a century, to work with before commercially viable oil deposits are exhausted. (Thug states remain a problem.) (Or maybe two centuries recovery techniques get better and better).
But, it gets better. What if PHEVs become viable. Then we see actual steep declines in oil consumption. People drive to work and back and use zero liquid fossil fuels – and this happens all over the world.
One thing is almost certain: If oil stays above $60 a barrel, we will see continual declines in oil demand.
I would not go so far as to say “no worries.”
Unfortunately, due to thug states, oil supply could be erratic. This could lead to price spikes and recessions. Another worry is that oil prices collapse on their own, undercutting electric cars, and leading to huge losses in that arena, and many other alternatives.
Still, we may on the edge of one of the great epics in human history: Cleaner fuels, yet still abundant.
RR has posted on promise of geotheral in US, perhaps 10 percent of our use. Germany is doing great with wind and solar.
We still can go to nukes.
What is not to like in this scenaro: We migrate to PHEVs, radically dropping oil consumption while cleaning the air, and reducing CO2 emissions.
And, why is this not a realistic scenario (other than George Bush being president)?
“And, why is this not a realistic scenario (other than George Bush being president)?”
What happened in energy under clinton? That’s right…nothing!
Yeah, but Clinton was Prezzy when oil was cheap, and both Houses controlled by the R-Party. He should have done more, but could of he?
In sharp contrast, Bush had carte blanche to do whatever he wanted after 9/11, and he has been prezzy in an era of higher oil prices, and for most of that had an R-Party running both Houses.
In spite of all of that, Bush has accomplished nothing; if possible he accomplished worse than nothing with his Iraq adventure.
We have no energy program I can detect, other than to stay on good terms with KSA (Bush buddies), even if they finance terrorism worldwide, and cut oil production as prices shoot over $70 a barrel.
If you can even identify what is Bush’s energy program, let alone disagree or agree with it, I would like to know what it is.
That solar thermal company that GreyFalcon and Benjamin Cole mentioned…. Ausra seems to claim that they could generate electricity for a Levelized cost of Energy of 7.8 cents/KWH using their current technology on a 92 mile x 92 mile area of the Mohave desert to supply 92% of the current US electricity requirements 24 hours a day, 365 days a year, including the cost of 16 hours of thermal storage.
http://www.ausra.com/pdfs/T_1_1_David_Mills_2049.pdf
http://www.ausra.com/technology/myths.html
Is it irrational exuberance, or is it realistic?
I found an article that may answer my question.
http://www.sciam.com/article.cfm?articleID=1FC8E87E-E7F2-99DF-3253ADDFDBEC8D41
Ausra claims to have solved the storage problem without using molten salts or other expensive means of conserving heat….
The system will employ pressure and a steam accumulator to accomplish the trick. “You allow some of the steam to recondense,” O’Donnell explains. “It flashes back to steam when you reduce the pressure just by opening the valve to the turbine.”
Such long-term steam storage, however, is unproved. “Steam storage is currently feasible at small levels, for example, one hour or so,” NREL’s Mehos notes. “Due to large volumes and high pressures involved with steam storage, scaling up steam storage to baseload applications is very high risk.”