Taiwan receives an average of 1644 hours of sunlight a year. The concentration of that sunlight yields an average ratio of approximately 1 KW per square metre. The combined surface area of all of Taiwan's cities (including Taipei County) is 3,422 km2, although only perhaps a third of that (1,140 km2) will take the form of building rooftops. The best commercial solar photovoltaic cells in the world convert about 22% of the light that hits them into electricity. I believe those used at the Lhuju pilot plant in Kaohsiung County (pictured above) convert something like 15%. Let's imagine that conversion was 100% and let's pretend you could build solar cells on that total area of 3,422 km2 and do the math...1 KW multiplied by 1644 hours yields 1.644 MW hours per m2, per year.
1.644 MW hours per m2 multiplied by 1,000 yields 1.644 GW hours per km2, per year.
1.633 GW hours multiplied by 3,422 yields 5.625 TW hours per year.
So that's less than 6 TW hours per year from solar photovoltaic cells assuming 100% conversion of light into electricity (instead of the current state of the art rate of 22%) and further assuming that such solar photovoltaic cells are fitted to every rooftop of every kind of building in Taiwan in addition to the construction of multiple solar power plants and solar "trees" such as this one in Keelung above. The energy output of Taiwan's three aging nuclear power plants is >40 TW hours per year. Therefore anybody who claims that solar power can replace nuclear power in Taiwan, such as Gavin Lee (李佳達), is either a fool or a liar and I don't give a damn whether they are affiliated with Harvard or any of the other bullshit factories.
"1 KW multiplied by 1644 hours yields 1.644 MW hours per m2, per year.
ReplyDelete1.644 MW hours per m2 multiplied by 1,000 yields 1.644 GW hours per km2, per year.
1.633 GW hours multiplied by 3,422 yields 5.625 TW hours per year."
There's a million square metres in a square kilometre, Mike.
Taiwan receives an average of 1644 hours of sunlight a year. The concentration of that sunlight yields an average ratio of approximately 1 KW per square metre.
ReplyDeleteWhat exactly is meant by "average of 1644 hours of sunlight" and how does that convert to 1 KW per square meter?
The number of 1644 hours is out there on the web as the average number of sunlight hours per year in Taiwan. It's not the same as daylight hours, and instead is probably related to the amount of cloud cover in a given region (a brief search didn't turn up the precise definition, but it's a commonly-used term).
ReplyDelete1kW per square metre is probably an overestimation. Insolation on Earth is around 1.4kW at the top of the atmosphere. Attenuation and the projection effect means that this number is significantly less most of the year. 1kW per square meter is the effective insolation for a region perpendicular to the sun, but given Taiwan's latitude it's only directly perpendicular to the sun for a few days a year (and in fact anything north of Chiayi is NEVER perpendicular to the sun).
So actual solar insolation on Taiwan is substantially less than 1kW per square metre; Mike was being generous.
Jesus Christ that's embarassing...
ReplyDeleteOK I'm the one who crapped all over myself there, so I'm the one who ought to clean it up...
ReplyDeleteClearly, if that 5.6 TW hours is a million times short of the mark, then it would be a staggering understatement to admit I was way ahead of myself to say that it isn't physically possible for solar power to replace nuclear power.
I deserve a right slap for that.
A less hyperbolic and more reasonable question would be how much it would cost in both land and dollars to replace nuclear power with solar power... and as it happens I myself answered this question previously in a published letter.
Not only did I mangle simple square root calculations, I even forgot that I'd answered the same question far more satisfactorily on a previous occassion.
Slap me again.
I think I'd better apologize, drink some gin listen to some Kinks records and then forget about this.