Does that use a lot of energy? • Hacker News Board

Re: Does that use a lot of energy?

#221

Post by harrall » Fri, Mar 06, 2026, 7:32 PM UTC

dmd wrote: post #219

harrall wrote: post #217

Earlier quoted context omitted.

Oops it’s actually 0.6 TW. https://ourworldindata.org/energy-production-consumption Convert TWh to TW for a year average.

Huh! I'm kind of stunned that we only use ~30x the power that we did back then. If I'd been asked to guess I would have added another 0 or even two of them.

Yeah we had an exponential jump when we discovered oil but we maxed that out and the growth has been linear since (and paying for it environmentally too).

I’m waiting for the next big major discovery in energy generation.

We’re always on the verge of fusion… fusion will be like the discovery of oil. Humanity will jump forward… well, technologically at least.

Re: Does that use a lot of energy?

#222

Post by dataspencer » Fri, Mar 06, 2026, 8:54 PM UTC

I find this at best non-enlightening and at worst misleading because there is no consistent unit of comparison: 10 minutes here, 1 hour there, 10 miles somewhere else. That renders the visual comparison of a bar chart pretty uninteresting, no?

Re: Does that use a lot of energy?

#223

Post by eru » Sat, Mar 07, 2026, 2:26 AM UTC

michaelt wrote: post #160

eru wrote: post #154

Why does their air con take 1kW to run? I wonder how much below ambient they are setting their temperature, and how old that aircon is and how bad the insulation? The washing machine seems also inefficient. My dryer is also a lot more efficient than theirs, at least if Miele's app is to be believed about how much it uses each cycle.

> Why does their air con take 1kW to run? The author is in the UK, so they probably looked at a product like [1] which is "ideal for rooms 16-26m²" and has cooling power consumption of 1005W. Residential air conditioning in the UK often involves small, noisy units that are only used for a few weeks at the height of summer. They'll have a thermostat built in, sure, but the user will eagerly turn them off when the room…

Yeah, looking at the text at the bottom, I looks like they took the peak power usage of their AC, not the steady state.

Re: Does that use a lot of energy?

#224

Post by eru » Sat, Mar 07, 2026, 11:53 AM UTC

toomuchtodo wrote: post #161

eru wrote: post #150

Earlier quoted context omitted.

You have pretty much the same heat losses with nuclear, or anything else where you heat water to turn a turbine.

Nuclear is low carbon, it’s fine we lose heat to extract that energy versus stationary and mobile combustion generation, as there is no other effective way to extract that energy at this time. Quantification of global waste heat and its environmental effects - https://www.sciencedirect.com/science/article/abs/pii/S03062... - Applied Energy Volume 235, 1 February 2019, Pages 1314-1334 * 49.3–51.5% of global energy use…

I made no claims about carbon.

Re: Does that use a lot of energy?

#225

Post by eru » Sat, Mar 07, 2026, 12:02 PM UTC

lesuorac wrote: post #198

eru wrote: post #149

Earlier quoted context omitted.

I love Technology Connections, but he has no idea what discounting is in economics. Or at least he writes his videos as if he doesn't.

What discount rate are you using? Solar has one of the lowest capital costs [1] so the discounting works in it's favor. And then the non-discountable operating costs also works in its favor since the fuel supply (light) is free. [1]: https://en.wikipedia.org/wiki/Cost_of_electricity_by_source#...

No, the problem is he speaks like he doesn't understand discounting at all. He treats a recurring revenue (or energy) as fundamentally different from a one time gain, as opposed to something you funge via discounting rates.

You are one level ahead: I'm more than happy to debate what discounting rates you should be using!

Re: Does that use a lot of energy?

#226

Post by eru » Sat, Mar 07, 2026, 12:02 PM UTC

cogman10 wrote: post #207

lesuorac wrote: post #198

Earlier quoted context omitted.

What discount rate are you using? Solar has one of the lowest capital costs [1] so the discounting works in it's favor. And then the non-discountable operating costs also works in its favor since the fuel supply (light) is free. [1]: https://en.wikipedia.org/wiki/Cost_of_electricity_by_source#...

Yup. It's why even in fairly red states like my own (Idaho) solar, wind, and battery are going up everywhere. Even without significant subsidies the economics are really good for renewables. They'd be even better if we didn't have extreme tariffs on China. That's actually what's convinced me that renewables are a better choice than nuclear. I still like nuclear, but renewables are just so much easier and faster to de…

Yes, the tariffs on Chinese PV and EV are really crazy.

Well, at least we don't believe in tariffs where I chose to live.