>If a breakthrough of solar technology occurs and the cost of photovoltaics
came down enough that we could deploy panels all over the countryside,
what is the maximum conceivable production? Well, if we covered 5% of
the UK with 10%-efficient panels, we’d have
This paragraph is titled "Fantasy time". So before I start the criticism, I would like to thank him for clearly debunking fantasies about hydro and geothermal, where aside from ground-source heat pumps and sparsely populated mountains, they are simply too small. Photovoltaics are the largest source of sustainable energy by far, so the results of an overall analysis will be heavily dependent on the treatment of solar panels.
At the same time, I think it's practical to assume that humans will aggressively innovate the properties and production of PV panels, because the potential value is so large. But I'm going to stick with existing technology. The Agua Caliente farm in Arizona:
As such, describing solar farms as a fantasy, and upper bounding the efficiency at 10%, when there are existing installations built with solar panels at 16% efficiency, seems too pessimistic. Looking ahead to other technologies, perovskites, considered a low-cost option, were recently pushed to 25%:
and Alta Devices demonstrated 29% efficiency with a GaAs thin-film before a buyout by a Chinese firm led to a class-action lawsuit filed by disgruntled employees:
>most countries will be in the same boat as
Britain and will have no renewable energy to spare
A glance at a map will immediately show the viewer that Britain is one of the most poleward and densely populated countries in the world — a worst-case scenario for solar electricity. Even Japan has the benefit of sitting significantly further south.
Yikes, those are some really bad assumptions. It's been a decade since I've read the book, so skimming now I'm seeing an awful lot of hot air in the assumptions that went into it.
For example, the mythical, never built, "clean coal" shows up in most of the potential scenarios for the UK! That was an obvious stinker back when the book was written, but to simultaneously give the benefit of the doubt to charlatans, and then misestimate solar and wind so much is pretty unforgivable.
I think we perhaps give the book too much credit because it converted everything into understandable units, which is the primary utility of the book. But that utility papers over a lot of really bad judgement, so using it as a guide for sustainable energy leads to really bad conclusions.
Yeah consumer panels are routinely 18 - 20% efficiency now. But these are the ideal numbers. To be fair he doesn't derate the efficiency of PV as happens in the real world, so the degree to which 10% is an underestimate is mitigated. I don't think this substantively changes the analysis, it just means less reliance on nuclear in the various models. Additionally, in a gloomy country like the UK the more you rely on solar the more you need advanced storage and grid solutions to deal with the inconsistencies.
And agree that the comment about other countries is not correct. Australia for example will pretty soon be able to meet 100% energy demand with renewables on sunny days and is looking to export power.
Agreed, the 10% seems like a solid estimate, at least for today, but it seems quite likely that new tech could bring that up to 15% or more, which is a 50% in efficacy. Wikipedia says that current panels are getting a 10% capacity factor now, which is only 40% - 50% of what can be had at sites with good solar. That capacity factor seems to be slowly climbing since 2008 as well.
This paragraph has some pretty bad predictions by MacKay though:
>The solar power capacity required to deliver this 50 kWh
per day per person in the UK is more than 100 times all the photovoltaics
in the whole world.
This is a completely irrelevant and pointless thing to state.
> At the start of this book I said I
wanted to explore what the laws of physics say about the limits of sus-
tainable energy, assuming money is no object. On those grounds, I should
certainly go ahead, industrialize the countryside, and push the PV farm
onto the stack. At the same time, I want to help people figure out what
we should be doing between now and 2050. And today, electricity from
solar farms would be four times as expensive as the market rate.
Overlooking that Solar PV had already fallen precipitously in cost in 2008, and assuming that a four-fold fall was not a given, was a huge mistake.
> So I feel
a bit irresponsible as I include this estimate in the sustainable production
stack in figure 6.9 – paving 5% of the UK with solar panels seems beyond
the bounds of plausibility in so many ways. If we seriously contemplated
doing such a thing, it would quite probably be better to put the panels in
a two-fold sunnier country and send some of the energy home by power
lines.
5% of the UK is about the same percentage of the UK that is occupied by houses and gardens. Putting solar panels on all roofs could probably get to 10 kWh/d or more. Converting only a very small amount of arable land, which has already been taken out of nature, to solar panels, could get the UK to 5% easily.
The skepticism of solar and embrace of tech like clean coal and nuclear were big misses here.
http://www.withouthotair.com/c6/page_41.shtml
>If a breakthrough of solar technology occurs and the cost of photovoltaics came down enough that we could deploy panels all over the countryside, what is the maximum conceivable production? Well, if we covered 5% of the UK with 10%-efficient panels, we’d have
This paragraph is titled "Fantasy time". So before I start the criticism, I would like to thank him for clearly debunking fantasies about hydro and geothermal, where aside from ground-source heat pumps and sparsely populated mountains, they are simply too small. Photovoltaics are the largest source of sustainable energy by far, so the results of an overall analysis will be heavily dependent on the treatment of solar panels.
At the same time, I think it's practical to assume that humans will aggressively innovate the properties and production of PV panels, because the potential value is so large. But I'm going to stick with existing technology. The Agua Caliente farm in Arizona:
https://www.solarfeeds.com/mag/solar-farms-in-the-usa/
uses CdTe panels from First Solar which are currently manufactured with about 16% efficiency:
https://www.firstsolar.com/-/media/First-Solar/Sustainabilit...
As such, describing solar farms as a fantasy, and upper bounding the efficiency at 10%, when there are existing installations built with solar panels at 16% efficiency, seems too pessimistic. Looking ahead to other technologies, perovskites, considered a low-cost option, were recently pushed to 25%:
https://www.pv-magazine.com/2021/04/06/unist-epfl-claim-25-6...
and Alta Devices demonstrated 29% efficiency with a GaAs thin-film before a buyout by a Chinese firm led to a class-action lawsuit filed by disgruntled employees:
https://en.m.wikipedia.org/wiki/Alta_Devices
I also take issue with the assertion on page 115:
http://www.withouthotair.com/c19/page_115.shtml
>most countries will be in the same boat as Britain and will have no renewable energy to spare
A glance at a map will immediately show the viewer that Britain is one of the most poleward and densely populated countries in the world — a worst-case scenario for solar electricity. Even Japan has the benefit of sitting significantly further south.