dredmorbius@joindiaspora.com
Doc Morbius (moved to Glasswings)

Switching to Renewables: How much energy is available?

A reasonably good explainer on the potential for powering humanity on solar power: It's interesting and better information than I'd feared, though it still omits a lot, mostly in terms of baked-in assumptions of energ consumpion increases from future wealth and population increases. An apparently-large solar energy surplus rapidly diminishes within just the next century.

https://www.youtube.com/watch?v=IZEaYjo4ZJU

Basic facts:

  • Global energy consumption is about 400 quadrillion BTU (quad), or 10,000 million tonnes of oil equivalent (mtoe), or 115 petawatt hours (PWh -- 115 million GWh) equivalent. Those are units, and they're big. The important thing is to look at the total amounts and what they translate to on a per-person basis.
  • US consumption is about 100 quad, / 2,500 mtoe.
  • Total incident raw solar power is about 7,000 times human energy use. That's what "as much solar energy falls on the entire Earth in 1 hours as humans use in an entire year" translates to. But after figuring in various losses (land vs. water, usable daily hours, panel efficiency, other losses), what's left is closer to 100--200x current total human energy use. And some of that's got to go to both our own food supply and the rest of the environment.
  • The Rest of The World (Non-OECD countries / countries outside North America, Western Europe, Japan, Australia) uses a tiny fraction of the energy of the West. That's 6x the people (roughly) and about 1/3 the per-capita energy use. Note that this includes China and India, which have greatly in creased energyy usage per capita over the past 3 decades as they've industrialised.
  • Global population is projected to grow to somewhere between 9--12 billion by 2100 or so.
  • There's still the question of energy storage, dispatchable energy use, and the need for fuels in transportation uses, most especially marine shipping, air travel, and rockets, none of which can rely on battery or grid-supplied electricity.

Even just accounting for present population and average OECD consumption, that's another 6 * 3 or 18 time more energy consumption that is presumed just to bring the rest of the world up to average OECD levels of energy affluence.

We only had about a 100x headway in net solar energy surplus to begin with, this would cut through about 1/5 of that. Without considering future energy growth or additional energy affluence among either OECD or other nations.

Efficiency gains, especially reducing the two-thirds of all energy lost (mostly in conversion from thermal to mechanical energy) will buy us back some of that, but this is a one-time bonus, and it's going to be much less than the total lost energy. The 2nd Law of Thermodynamics always wins out, and there will be energy efficiency losses.

We're using a lot of energy, and the dreams we're selling our children and the world involve a huge increase on even that. I don't doubt that the future will be solar powered, mostly. I do have doubts it will be a high-energy solar future.

Again, the ultimate critique here is not against renewables. We have no other choice. Our high-energy, large-population lifestyle is inherently unsustainable.

Data:

OECD:
- 3,784 mtoe energy (2018)
- Population: 1.3 billion (vs. 7.8 billion global, -> 6.5 billion non-OECD)
- Per-capita consumption: 2.9 tonoil (7.6 tonoil US).
- 38 member states: Australia, Austria, Belgium, Canada, Chile, Colombia, Costa Rica, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Israel, Italy, Japan, Latvia, Lithuania, Luxembourg, Mexico, Netherlands, New Zealand, Norway, Poland, Portugal, Slovakia, Slovenia, South Korea, Spain, Sweden, Switzerland, Turkey, United Kingdom, & United States.

Non-OECD
- 6,216 mtoe
- population: 6.5 billion
- Per-capita consumption: 0.96 tonoil

OECD energy and demographics from:

https://www.iea.org/reports/key-world-energy-statistics-2020/final-consumption
https://en.wikipedia.org/wiki/OECD

#Energy #Resources #Limits #Solar #SolarPower #LimitsToGrowth #Population #DoTheMath #Video #YouTube

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