David MacKay's TEDxWarwick talk uses basic arithmetic to show how much land and energy renewables would need to power a country like the UK. It explains the limits of sustainable options and why they should still be pursued.
Why Hacker News points people here: Cited in energy debates for its back-of-envelope scale of the transition and the land and storage limits of wind and solar.
“I found this ted talk on the feasibility of various renewable energy sources quite eye opening”HN comment, 2019
Well, a bunch of countries have more or less agreed on aiming for no more than 1.5 degrees warmer. IPCC made a report on what that would entail stating basically that even with an overnight abolishment it cannot be reached. But that if we assume it feasible to use afforestation and other techniques to extract CO2 from the atmosphere in the future we might have chance to reach that target for 2100 given we stop using fossil fuels by 2030. Given the scale of the transition necessary, overnight or 11-years is more or less the same time frame Edit: Great TED-talk on the scale of what’s needed this video
RecommendsCuriousSkepticJan 2019
“I found this ted talk on the feasibility of various renewable energy sources quite eye opening”
Feasibility of various renewable sources
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On that topic, I found this ted talk on the feasibility of various renewable energy sources quite eye opening this video
RecommendsneilwilsonMar 2019
“Good video by the late David Mackay on that point here.”
Energy density per head limits wind and solar
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Not everywhere in the world has the land area to do wind and solar. In fact pretty much everywhere other than Russia, Australia, Canada, the US and Brazil. There the energy density per head of population is too high for renewables. Good video by the late David Mackay on that point here. this video
Recommendskinjba1Aug 2020
“showing the downside of renewable energy - such as the enormous land usage and reliable energy storage”
Downsides of renewables: land use and storage
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No energy source [that we've discovered so far] is perfect. All have downsides. Sadly, living in denial of that fact is more popular than ever, but that's a separate topic. Here are a couple TED talks showing the downside of renewable energy - such as the enormous land usage and reliable energy storage needed to compete with nuclear or fossil. Why renewables can’t save the planet link A reality check on renewables this video
Cites itspodekMar 2017
MacKay's TED talk alongside his book
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If you haven't read Sustainable Energy Without the Hot Air , by David Mackay, I recommend it. Free download: link About the author: David MacKay FRS is the Regius Professor of Engineering at the University of Cambridge. He studied Natural Sciences at Cambridge and then obtained his PhD in Computation and Neural Systems at the California Institute of Technology. He returned to Cambridge as a Royal Society research fellow at Darwin College. He is internationally known for his research in machine learning, information theory, and communication systems, including the invention of Dasher, a software interface that enables efficient communication in any language with any muscle. He was appointed a Lecturer in the Department of Physics at Cambridge in 1995 and was a Professor in the Department of Physics from 2003 to 2013. Since 2005, he has devoted much of his time to public teaching about energy. He is a Fellow of the Royal Society. Nine months after the publication of 'Sustainable Energy - without the hot air', David MacKay was appointed Chief Scientific Advisor to the Department of Energy and Climate Change. TED talk: this video Harvard talk: link
Cites itppfApr 2019
“There's also space limits - see”
Space limits of renewables
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"Renewable" doesn't mean "free energy". Constructing renewable energy sources (wind, solar, etc) takes more energy than constructing an equivalent non-renewable energy source - this is the EROEI (energy returned on energy invested). There's also space limits - see this video What's apparent to me is that we live in a unique era where energy is abundant and cheap, which may never be repeated (unless fusion power is developed).
Cites itwiz21cMar 2021
Cited for the maths of building renewables
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What about the resources needed to build the solar and wind infrastructures ? Metal, extraction of that metal, rare earths,... ? I'm all for solar and wind and whatever, but at some point there are some maths to do... this video
Cites itkinjba11May 2021
“Briefly: solar and wind energy requires sun or wind and tons of space relative to fossil/nuclear.”
Solar and wind need space
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Briefly: solar and wind energy requires sun or wind and tons of space relative to fossil/nuclear. Not every place has those. "A reality check on renewables" this video
