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CarlShulman comments on Review of Kurzweil, 'The Singularity is Near' - Less Wrong
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It doesn't help his case that in recent years increases in clock speed have slowed.
The original Moore's law talked about not the clock speed, but the number of gates per IC, which has been holding up OK, if you count multicores, although even that metric shows signs of falling below exponential.
Clock speed isn't the only measure of CPU performance. In fact, it isn't much of a measure at all, given that new processors are outperforming Pentium 4 chips (ca. 2005) by the factor you'd expect from Moore's law, despite the fact that their clock speeds are lower by as much as a half.
What really matters (and what Kurzweil emphasizes) is (computation power) / (dollar).
I agree with that, but that leads me to my big problem with Kurzweil.
Whenever I hear him talk about exponential growth in solar power, it's always about installed base, and not watts/dollar. As a practical matter, since we're talking about capturing a finite surface flux, I don't see any way for this to be go exponential in watts/dollar for practical purposes, given the cost of land use.
Even if you go exponential in the underlying technology, eventually giving away free mylar type sheets capturing 100% of incident solar flux (and say we're around 20% of flux now), you've still got all the costs of land and electrical distribution that aren't getting exponentially cheaper themselves. And we've really only got a little over 2 doublings of percentage of surface flux to go and we're done.
His plots of exponential installed base just seem a dishonest way of claiming that exponential growth is occurring in solar, and that gives me pause about trusting his other claims.
Similarly, just because we're using silicon manufacturing methods for solar doesn't make it an informational technology subject to exponential growth, but he talks like it does. Digital information technologies can go expoenntial because they can keep going smaller, but you can't do that if you're trying to capture a surface flux.
Orbital solar power stations. Granted, it's only a temporary extension before the exponential starts stagnating, but it's just one example of how the limit of Earth's land area could be overcome. The eventual limit is capturing all of sun's energy output, e.g. with a Dyson sphere, with near-perfect efficiency.
My point about surface flux wasn't about the limit of surface area to work from, but a limit on how much flux was passing through any square meter. Unlike semiconductor technology, you can't just keep going smaller to improve performance.
And I don't think orbital satellites are likely to be competitive with land on a cost per square meter basis for a while.
But this isn't my bigger concern. I'm more worried about the intellectual error involved, which lessens my trust in his other conclusions. Either he doesn't recognize the mistake, or he does.
http://bigthink.com/ideas/31635?page=all Ray Kurzweil: Solar Will Power the World in 16 Years
During his latest Big Think interview, Kurweil explained:
Notice the sleight of hand. The cost per watt (of a panel, not of the energy delivered to a customer) is "coming down dramatically". Has that been exponential? Where is the curve? What is the doubling time? Also, are the land costs held fixed? Many of the newer, cheaper technologies trade off efficiency of the semiconductor used versus increased area used.
But instead of even showing us data on cost per watt, he starts talking about the aggregate power generation from solar, and how it has been on an exponential progression, and bases his predictions on that. That's either a fundamental mistake or a deception.
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Maybe you missed my point. I want to see exponential growth in watts per dollar for total system cost.
There's a paragraph near the end that doesn't make a lot of sense, with a chart *with data only from 2005 to 2009, projected out to 2031." The fact that someone would project out 5 years of data for 27 more years does not fill me with confidence. Even the supposed crossover point is 2020, 11 years after his 5 year window of data.
This is another guy who is looking either dishonest or sloppy, conflating power per dollar for system and panel costs.
Very simple. Show a multidecade plot of power per dollar for system cost - with actual multidecade data, and not just projections. Let's see if it's exponential, and let's see what the doubling time is.
And then given the cost, let's see if Ray's projections for solar power generation look reasonable. I really doubt it.
Here's the Nation Renewable Energy Laboratory market report.
Page 62 has whole-system costs for 1998-2010, which fall about half (which doesn't reflect the recent drop of solar cell prices towards production cost, the alleviation of the silicon shortage caused by unexpectedly rapid growth, and the overshoot below cost due to Chinese subsidies).
There are module (not just PV cell, those are earlier) price data back to 1980 on page 60, also with a doubling time around a decade.
You can also look at this paper for more LCOE data:
Thank you for the diligence.
I think the graph on page 63 has the best installation data. Again, same years as the graph on 62, but breaking out the installation and pv costs separately. The installation costs went down about a third in 12 years. The internal trend looks a lot worse, with 2005-2010 being essentially flat, but lets go with the 35% drop. You wanna get out a calculator to figure out the halving time? Let's say conservatively, 15 years.
Meanwhile, Kurzweil's talk, from 2011, says that solar will rule the world in 16 years. Will another 35% reduction in installation costs make solar "rule the world"?
Looks like we're continuing our previous conversation: http://lesswrong.com/lw/dm5/why_could_you_be_optimistic_that_the_singularity/71cs
From last time, we had $3.30 per watt on installation. At $2.20 per watt in 15 years, and assuming free solar cells, will solar rule the world?
Maybe hopeful. They had coal at 2.10 per watt on the wikipedia page. Of course, the PVs won't really be free, but it does look competitive.
You've made me a little more hopeful.
I think it's materials science that eventually makes the difference, when we start replacing window panels with gorilla glass solar panels. The difference comes when solar is no longer something extra you add to a building, but part of the structure itself.
Hmmm, I'm not so sure. Yeah, we've got price per watt (Power), but it really should be price per kWh averaged over a day, which would include capacity factor, which is a big problem for solar. The panels seem cheap enough, but we need a big breakthrough in installation costs. I think it could happen, but the data doesn't predict it coming in Ray's timeframe.
In Little Science, Big Science Derek J de Solla Price does a great job talking about stagnation of exponential scientific growth curves. In general, an exponential growth curve must flatten at some point. He did things like look at the number of scientists in relation to the population. A quote:
It's been years since I read it, (and it's a good 50 years old) but I remember it was a good book, that was one of the founders of scientometrics. I would definitely recommend.
Kurzweil has never claimed that exponentials go on forever. He has claimed that many exponentials go on longer than the current technology would allow.
Even when there is only an overhead of 100X in which to grow something, knowing it is probably going exponentially with T timescale gives you a very different sense of the midterm future than thinking it is stagnant or saturated or linear. And the singularity is all about the midterm.
http://www.pbs.org/wnet/need-to-know/environment/futurist-ray-kurzweil-isnt-worried-about-climate-change/7389/
Ray sez
That's what he claims. He does it based on two mistakes - calling solar an information technology, and switching from looking at exponential growth in util/dollar to exponential growth in installed base.
See this article, and the links to the NREL for cost data (which Kurzweil does also talk about). Solar energy output per dollar has been improving with a doubling time of about a decade for several decades. If that trend continues, then it will be cheap relative to existing alternatives by the time Kurzweil projects gigantic market share. And prior to that there are markets in areas where competing electricity is expensive (theft on the lines in India, lack of connection to the grid in poor areas, the correlation of solar with peak load for air conditioning, places with carbon taxes) to absorb a lot of growth.
And cost improvements come not only from efficiency in absorbing flux, but from reduced use of materials, more efficient manufacturing processes, and so forth. Balance-of-system costs have also been going down. Distribution costs apply to other power sources (although distributed solar in some places benefits because homeowners can use the solar themselves, and free ride off the utilities for distribution, an implicit subsidy for early growth). Non-arable desert land is not particularly high value, nor are roofs.
This isn't really true--clock performance is a really good metric for computing power. If your clock speed doubles, you get a 2x speedup in the amount of computation you can do without any algorithmic changes. If you instead increase chip complexity, e.g., with parallelism, you need to write new code to take advantage of it.
Wrong. A two-fold increase in CPU clock rate implies a twofold increase in CPU cycles per second, and nothing more. Any number of pure hardware improvements - for example, increasing the number of instructions, decreasing the number of CPU cycles an instruction takes to execute, improving I/O speed, etc - can improve performance without changing the clock rate, or even while decreasing the clock rate, without introducing parallel processing cores.