|Ivanpah Solar. This is only one-third of it. Then you need 5x the area|
for same capacity as Diablo Canyon and then 4x that to get to
equivalent electricity production per year
South China Morning Post
fact-checker is Charmaine. (I’m sure not the only one, just the one I’ve dealt with a few times. Very decent and conscientious).
She had a couple of questions about the letter I submitted (questions I’ve only just got to, three days late)
1. Subsidies. I’d said that our electricity provider, China Light and Power (CLP) pays us for the solar power that we put into its grid via our rooftop solar panels — the Feed in Tariff — an amount five times more than the going rate for the grid power delivered by CLP. This was subsidised by the HK taxpayer, I said.
Charmaine said it was not “the HK taxpayer”, but that costs to CLP were offset by selling Renewable Energy Certificates. I agreed I was wrong in saying it’s “the Hong Kong taxpayer” subsidies, so agreed with her edit to simply refer to “subsidies “.
In deep recesses of my mind I knew something about RECs, which are part of the whole carbon trading thing. It’s still a subsidy, of sorts, to CLP, and to us, as we would not have installed solar panels without it. At list price for electricity — the price we pay to CLP — it makes no economic sense at all to install rooftop solar panels, no matter how concerned one may be about climate change.
2. Area of land needed for solar power vs nuclear power. Charmaine said she couldn’t find a reference to my figure of 450 times as much land used in the Ivanpah Solar station vs the Diablo Canyon nuclear station. (Which I had got from EnvironmentalProgress.org/California via Michael Shellenberger, Apocalypse Never, p.188).
She points out Ivanpah Solar, capacity 380 Mw, is on 3,500 acres. Diablo Canyon Nuclear, capacity 2.2 Gw, is on 750 acres. Like for like in capacity — one Gw is 1,000 Mw — Ivanpah Solar needs 27 times the Diablo Canyon Nuclear area. [(2200/380 x 3500)/750].
Of course there are other factors involved and we agreed to a Nuclear industry figure of 75 times the land area requirement, Solar vs Nuclear.
Since then, I’ve looked into it a bit more and I can justify the 450 times figure, because:
A. There is a 4-fold difference in annual electricity production between Solar and Nuclear for any given capacity. Ivanpah Solar net production p.a. is 21% of its capacity. Diablo Canyon Nuclear net production is 88% of its capacity. Therefore the land use figures have to be adjusted to take account of that to compare like for like in terms of actual electricity production. You need to create approx 4 times the Solar capacity to get the same amount of net electricity per year as Nuclear. 88/21 = 4 times the 27 from above = 113 the land area needed, Ivanpah Solar vs Diablo Nuclear.
But there’s more!
B. The stated 750 acres for Diablo is way too much: When I thought about it, it seemed excessive. I have visited the Daya Bay Nuclear power station in China, which the same capacity as Diablo Canyon. I’ve also owned farm acres in Australia; I know what 40 acres looks like; I know what 100 acres looks like. 750 acres is a block 1.75 km by 1.75 km. This is huge! Quite simply, it is a gross overestimate of the land needed for an equivalent sized nuclear station. At a guess Daya is on ~40 acres. Certainly nowhere near 750 acres, which is simply incredible. As in not credible.
Then: Look more closely at the Wikipedia entry in Diablo Canyon and you find that the power facility is on just 12 acres! And that the owner of Diablo Canyon, Pacific Gas & Electric owns owns over 12,000 acres surrounding Diablo. At a guess, I’d say the 750 figure is just notional, plucked from the air. Perhaps the area that PG&E has notionally allocated to Diablo Canyon, though not the area needed to generate the power.
Now, it doesn’t need to be in just 12 acres. Allow for lawns and buffer area and say 40 acres. Then you get to 500 times the area of land needed for equivalent Solar to Nuclear [(2200/380)*3500/40]. To get exactly to the 450 x figure you need to allow 45 acres for Diablo Canyon. Looks about right to me! More than enough, from my eyeballing of Daya Bay. And eyeballing Diablo Canyon, below:
|Diablo Canyon Nuclear station. No way that’s 750 acres!|
ADDED: I ran the ruler over the GoogleMaps of Diablo Canyon and got around 80 acres. Which would make that multiple just over 250.
fact-checker Charmaine letter below the fold: