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.
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.
During his latest Big Think interview, Kurweil explained:
“Solar panels are coming down dramatically in cost per watt. And as a result of that, the total amount of solar energy is growing, not linearly, but exponentially. It’s doubling every 2 years and has been for 20 years. And again, it’s a very smooth curve. There’s all these arguments, subsidies and political battles and companies going bankrupt, they’re raising billions of dollars, but behind all that chaos is this very smooth progression.”
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.
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:
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”?
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.
Demo innovations (i.e. grist for the future, not already in the aggregate data) lately have included robots to do installation, designs with reduced installation reqs. The US DOE Sunshot Initiative page has the details of their programs supporting BOS, easier permitting, and so forth, although they have some interest in spinning a positive picture.
Cheap panels does suggest risk of slowdown, but there’s also some room to shift further tradeoffs in design, i.e. as cost of manufacturing and efficiency become less of an issue more effort will go into designing panels that work well with the BOS improvements.
and assuming free solar cells, will solar rule the world?
It won’t dominate dark areas, or assume 100% load (without batteries that push back dominance later), or price out already built nuclear plants (or coal and gas plants, absent massive carbon taxes). The claim that we might build so much solar as to match today’s world electrical output (but not the output of that future time) wouldn’t be shocking to me, although my guess would be for it to take longer than Kurzweil predicts (there are more efficiency gains to be had, but efficiency gives you free BOS savings by letting you use fewer panels, and the other areas will have to step up, especially for the later parts of his prediction).
it’s only a temporary extension before the exponential starts stagnating
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 is clear that we cannot go up another two orders of magnitude as we have climbed the last five. If we did, we should have two scientists for every man, woman, child, and dog in the population, and we should spend on them twice as much money as we had. Scientific doomsday is therefore less than a century distant. -Derek J De Solla Price
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.
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.
>
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.
Demo innovations (i.e. grist for the future, not already in the aggregate data) lately have included robots to do installation, designs with reduced installation reqs. The US DOE Sunshot Initiative page has the details of their programs supporting BOS, easier permitting, and so forth, although they have some interest in spinning a positive picture.
Cheap panels does suggest risk of slowdown, but there’s also some room to shift further tradeoffs in design, i.e. as cost of manufacturing and efficiency become less of an issue more effort will go into designing panels that work well with the BOS improvements.
It won’t dominate dark areas, or assume 100% load (without batteries that push back dominance later), or price out already built nuclear plants (or coal and gas plants, absent massive carbon taxes). The claim that we might build so much solar as to match today’s world electrical output (but not the output of that future time) wouldn’t be shocking to me, although my guess would be for it to take longer than Kurzweil predicts (there are more efficiency gains to be had, but efficiency gives you free BOS savings by letting you use fewer panels, and the other areas will have to step up, especially for the later parts of his prediction).
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.