Status-Q

Hannah Ritchie has a splendid substack/newsletter called By The Numbers, and last week she published a very interesting thought experiment.

If you took the land that's currently used for growing biofuels, and, while still keeping it devoted to energy production, used the space for solar panels instead, how would they compare?

As she says,

"The numbers were quite staggering. So staggering in fact, that I doubted myself. I ran the calculations many times, convinced I’d accidentally added a zero somewhere. I asked Pablo to also come up with an estimate, without telling him how I got to my numbers. As it turns out, we took slightly different approaches, but landed somewhere similar."

The world uses about 32 million hectares of land for biofuels, which is pretty amazing in itself.  That's about the size of Germany.  And the main use of biofuels is in transport, where they currently meet about 4% of global demands.

But when she ran the numbers, Ritchie discovered that using the land for solar instead would generate about enough electricity to meet the world's needs.  Note - that's not the world's transport needs, it's the world's entire electricity consumption! 

Now, she wasn't proposing that you actually could or should do this simple swap; there are obviously all sorts of extra factors like infrastructure, environment, battery storage, etc.  But it's a very effective illustration of just how inefficient biofuels are as a way of generating energy.  (And it's worth remembering that you can often grow crops or graze animals under solar panels as well.)

Their second idea was to suppose that all of the world's road transport was to be decarbonised; something that skeptics often say could never be done because of the energy requirements.  What would that take?

Well, it would take about one-quarter of the land currently used for biofuels. The space that, at present, provides 1% of global liquid fuel.

In one of my YouTube videos, I talk about how I've wired up my solar/battery system to ensure the energy in my home battery isn't ever used to charge my car (which has a much bigger battery, so doing this doesn't normally make sense), while still allowing the car to be charged using any excess solar power.

I had a query from somebody who was confused about how it worked, so I did my best to answer, and we went to and fro in what became a decent-length conversation. He has a similar inverter to me, but had some fundamental misunderstandings about how it worked.

At first, I assumed this was because he had different goals: he lives in another part of the world where there's a lot more sun and a much less reliable electricity supply, for example. But no, it turned out he wanted to do the same thing as me, but was convinced it wouldn't work the way I had described it.

It turned out, in the end, that the source of his confusion was that he had asked four different LLMs (ChatGPT, Claude, Perplexity, and Grok) about how to configure the system, and they had all agreed that 'battery power is never used to power loads on the "Grid" port', which is actually incorrect.

What persuaded him, in the end, that my description was right, and that all four LLMs were wrong?

He read the manual.