Just a quickie as I have to catch a bus in half an hour…
That’s how I started this blog post earlier today. And I then proceeded to demonstrate exactly why you shouldn’t write and publish anything that requires fact-checking or basic arithmetic in less than half an hour. First up, it turns out that the “news” item I was critiquing was almost three years old. Way to be cutting-edge, jim.
Not content with staleness, though, I then added a healthy dollop of inaccuracy (dividing by a thousand — instead of a million — to convert square metres to square kilometres). It’s the sort of thing that wouldn’t have got published if I’d used my usual two-drafts process instead of dashing it off in twenty minutes.
Given that the maths error pretty much invalidates the second half of the blog post, it’s not something I can just amend. That said, the first half is still relevant. So I’ll leave that here as a reminder that we shouldn’t take the news at face value when they make technical-sounding statements like: “For an energy source to be commercially viable, it must reach an efficiency of 10%, which is an industry standard.” I’m going to take out the second half of the post though as it’s a bunch of arse based on a flawed calculation.
But I hope this all serves as a reminder that we shouldn’t take blogs at face value either. Thanks to Doormat for pointing out the error.
The BBC currently has an article heralding the news that Sun and hydrogen ‘to fuel future’. It suggests that a new nanotech breakthrough has made converting solar energy into hydrogen a practical method of fuelling our cars. On the surface it sounds quite interesting, but unfortunately there are serious problems with the article. It opens by telling us that:
Hydrogen Solar says it has managed to convert more than 8% of sunlight directly into hydrogen with fuel cell technology it has specially developed.
For an energy source to be commercially viable, it must reach an efficiency of 10%, which is an industry standard.BBC News: Sun and hydrogen ‘to fuel future’
That all sounds very interesting, but it doesn’t actually make any sense. For an energy source to be commercially viable, it must reach an efficiency of 10%, which is an industry standard. Er, 10% of what exactly? I just don’t get it. The reality is that for an energy source to be viable (in practical terms, forget commercialism for a moment), it must produce more energy than is used to extract, refine and distribute it. This is measured as a ratio (sometimes known as Net Energy Ratio, NER, or more precisely as Energy Returned on Energy Invested, ERoEI) not as a percentage. So crude oil, for instance, has an NER of between 30:1 and 90:1 (depending on the well). If you were to convert this to a percentage, it would equate to a return of between 3000% and 9000%. Is that what the 10% in this article refers to? An NER of 0.1:1?
Probably not, but lest you get blinded by the intro figures claiming some sort of magical commercial threshold of 10%, please be aware that those claims make no sense as they are currently written.
[The rest has been DELETED. See above.]