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Comment by jimmaswell | Hacker News Reader

> Without drastic improvements in air-conditioners’ efficiency, the IEA reckons, they will be burning up 6,000 TWhs by 2050.

I feel like future improvements in the efficiency and greenness of energy production have the potential to offset increasing energy demands. We could solve much of this faster if we'd just properly utilize nuclear, but politics get in the way of using efficient designs and public perception is unfairly negative despite it being the safest of all energy production methods[1]. If electric vehicles gain more traction then the emissions from the transport of materials for nuclear etc. also stop being a factor.

Side note, I hate this font they use that makes a 1 look like a seriffed I. Unnecessarily hard to read.

1: https://ourworldindata.org/what-is-the-safest-form-of-energy

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The problem with energy efficiency is that it paradoxically tends to increase consumption.

There’s a basic economic aspect we mustn’t forget - supply and demand. When energy prices drop, consumers often buy more if it.

I’m on mobile so I don’t have a link at hand, but I recall reading that people drove a lot less when gas prices were higher. When they went back down, people went back to driving more.

If you really want to lower energy consumption- just raise the price.

Lowering energy consumption isn't the end goal, lowering harmful emissions is. If in the future, energy is produced entirely by solar, hydro, and nuclear, vehicles/machinery use little or no fossil fuels, and air conditioners have continued to be improved wrt use of coolant/leakage, then there's no need to reduce consumption because consumption is harmless.

In the meantime, pricing poor people out of electric is not a good solution.

At some point waste heat itself will warm the planet enough to matter. With exponential growth one can get there pretty quickly. A few hundred years. At some point we should add a heat tax to compliment the carbon tax (that we should already have in place).

True, but very low priority compared to getting CO2 under control. From "Sustainable Energy – without the hot air" by David MacKay, pages 170 to 171:

"the average solar power absorbed by atmosphere, land, and oceans is 238 W/m^2; doubling the atmospheric CO2 concentration would effectively increase the net heating by 4 W/m^2. This 1.7% increase in heating is believed to be bad news for climate. Variations in solar power during the 11-year solar cycle have a range of 0.25 W/m^2. So now let’s assume that in 100 years or so, the world population is 10 billion, and everyone is living at a European standard of living, using 125 kWh per day derived from fossil sources, from nuclear power, or from mined geothermal power. The area of the earth per person would be 51 000 m^2. Dividing the power per person by the area per person, we find that the extra power contributed by human energy use would be 0.1 W/m^2. That’s one fortieth of the 4 W/m^2 that we’re currently fretting about, and a little smaller than the 0.25 W/m^2 effect of solar variations. So yes, under these assumptions, human power production would /just/ show up as a contributor to global climate change."

http://www.withouthotair.com/c24/page_170.shtml

It seems to me the assumption that energy consumption per person has peaked at the current European level and not increase in 100 years wildly false. Compelling new uses for energy will be found and other cultures are less likely, I think, to restrict personal energy consumption as much as Europe does currently.

That might be true, but remember that MacKay's numbers assume 100% non-renewable energy. In reality, solar panel prices are dropping fast, and they'll likely make up a substantial portion of the energy supply. Solar energy captured with photovoltaic panels is solar energy that's not heating the earth directly, so the waste heat problem is much smaller. The same is true for all renewable sources, e.g. winds and tides heat the earth uselessly if we don't capture them.

I agree. Keep power production on Earth to like 50% solar (wind, sunlight, tidal, etc) and there will be no problem with this heat issue. Bezos has specifically stated that he hopes to put industrial production off earth to avoid the industrial heat production problem in the far future.

> The problem with energy efficiency is that it paradoxically tends to increase consumption.

There's a practical limit to the increase in indulgence, after which the efficiency gain is all win.

We're not seeing a very dramatic effect or problem from inexpensive energy driving massively increased consumption in the US as one example. Efficiency is winning.

For example, US energy prices are 1/3 that of Australia, while per capita energy consumption is about 30% higher. US per capita energy consumption is comparable to Sweden, despite their energy prices being ~50% higher.

Natural gas is very cheap in the US, about 1/2 the cost in most regions. That doesn't mean I'm going to turn the temp in my house up to 87f this Winter.

The average fuel efficiency for vehicles has gone up by about 100% over ~45 years, while miles driven per capita in the US has increased by closer to 40-45%. Electric cars that get 90mpg equivalent, aren't going to cause people to drive 3x more than they do today.

US household energy consumption hasn't changed much in 20 years. Fridges got a lot more efficient over time on electricity, people still typically only own one of them per household. The same with furnaces and water heaters.

Smartphones sip electricity, especially compared to laptops and desktops - people aren't buying 20 of them to compensate for the dramatic difference in electricity consumption that results in using a smartphone instead of a desktop.

Most of the things we buy that consume energy have practical limitations on them, when it comes to how many of them we own or how much energy we'll consume with a given thing. As you reach those practical limits, efficiency starts to have a very positive effect.

Industrial level uses are much more sensitive to price. Get 1 cent/kwh electricity and your aluminum production is going to increase quite a bit, etc.

You'll still be constrained by the cost of the ore and the demand for the final product.

"The problem with energy efficiency is that it paradoxically tends to increase consumption."

Where's the evidence for that? Electricity consumption in most developed countries has been declining since around the mid-2000s.

Here in the UK, total electricity demand peaked in 2005 and has declined every year since, in spite of population growth (and more air conditioners!). Demand in 2017 was around 15% lower than in 2005, with about a 10% higher population.

https://en.wikipedia.org/wiki/Jevons_paradox

also https://www.axios.com/despite-renewables-growth-there-has-ne...

Jevons paradox only applies when the cost of energy is the dominating factor. If I replace my fridge with a newer more efficient fridge, I'm not going to buy more fridges: I don't have the space!

>If you really want to lower energy consumption- just raise the price.

Energy prices have a direct effect on all the getting stuff done that economies are based around. "Just increase the price" "Just shoot yourself in the foot" but pitched it in a way that doesn't sound miserable.

As other commenters have mentioned and provided citations for, lower energy prices correlate with increased consumption but at a diminishing rate.

The gains in efficiency for AC can be made via more efficient or retrofit building design.

Radiant heat barriers, deep-pack wall insulation, even growing vines on sun-exposed walls would all reduce cooling needs.

Or, a big shade tree, covering the house.

Nuclear costs are high and probably rising, renewables falling. I think renewables are the future on the whole, especially if storage tech keeps improving https://www.nirs.org/1011-old-reactors-vs-new-renewables/

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