Moving on to fusion power, MacKay says:
Fusion power is speculative and experimental. I think it is reckless to assume that the fusion problem will be cracked, but I’m happy to estimate how much power fusion could deliver, if the problems are cracked.
At [US levels of consumption] and 6 billion people, [deuterium] fusion would last 1 billion years.
MacKay is keen to stress that oceanic uranium extraction, the thorium energy amplifier and especially fusion are all unproven — though fast breeders are established kit. This is why he sees nuclear as a “stopgap”. He freely admits, however, that building new nuclear power stations is the most economic way of generating low-carbon power — and he confirmed to The Reg that in his view there would certainly be ample supplies of uranium to last the lifetime of any likely number of new UK plants.
MacKay sees nuclear as a “stopgap” and perhaps a “gamble”, but he fears that he may still have painted it in so positive a light that people will brand him as “pro-nuclear”. He emphasised to The Reg that he absolutely isn’t, and we believe him.
You can see why he’s worried about getting that label, though. Worst case, assuming that only the known technologies work and only the known reserves exist, MacKay tells us that the entire human race could power itself — transport, domestic, industry, the lot — at hugely profligate American levels using nothing but fission for around a century. Since it’s unlikely that everyone will suddenly ditch fossil and ramp up to that level of use overnight, realistically you’re talking about at least a couple of centuries; longer if people only fancied being Europeans rather than Americans. It wouldn’t even cost much, compared to renewables.
A pretty useful stopgap, then. And if any of the gambles pay off — oceanic uranium, new thorium tech or fusion — the human race can pretty much relax. We’re sorted for at least a millennium, by which point we’ll hopefully be mining other planets.
Having lined up his numbers, MacKay tries them out for size on various different agendas. He takes the low-hanging fruit in every plan, as he cuts off the oil and gas.
Firstly most transport is electrified, allowing millions of vehicle batteries to be used as power reservoirs to deal with grid fluctuations — though MacKay admits that people might be upset if the wind inconveniently dropped at the wrong time, perhaps leaving their cars flatlined when they needed to be charged up. He also allows some big land areas for growing biofuel to handle things which can’t be electric — some aviation would still be feasible, for instance.
Also, MacKay assumes big savings from more energy efficient buildings, universal home solar thermal and the use of heat pumps — helped out with “the promotion of sweater-wearing by sexy personalities”. Biomass heating is also used to the limit in every case, as is generation of energy from domestic waste.
All this leaves electricity consumption roughly tripled, and daily demand swings get worse. The difference in the various plans is how you deal with this.