A reality check on renewables - David Why is VENEZUELA a CATASTROPHY? - VisualPolitik EN 8 months ago   18:35

How much land mass would renewables need to power a nation like the UK? An entire country's worth. In this pragmatic talk, David MacKay tours the basic mathematics that show worrying limitations on our sustainable energy options and explains why we should pursue them anyway. (Filmed at TEDxWarwick.)

Lesson by David MacKay.

Comments 973 Comments

Jason Summer
The problem is that renewables and taking action at all has popularity issues
Jordan TRusso
So Nuclear energy is the obvious way of the future.
Téssio Fechine
What would the W/m² for fusion power be?
Sam Lair
The Glorious Temptations of Fossil Fuels — On Earth, in this life and in the future, it is understandable that we would want to continue using fossil fuels to fuel growth. We’ve developed marvelous technologies and wonderful industrial capacities based upon their use. However, it is inevitable that technology and science will evolve to higher and more sophisticated levels. Just as we no longer rely on wax and whale oil to light our nights, we will outgrow the need for coal and oil to power our civilizations; however.....
50 years ago I was anti-nuclear power, because we had no way to safely store the waste, which remains toxic for many thousands of time's longer, than any human civilisation has lasted. At the time, science told us that a safe solution was just around the corner, and they would have THAT problem solved very, very soon. The hubris to believe we have the ability to store and manage a product of such toxicity for tens, if not hundreds, of thousands of years, always leaves me shaking my head in disappointment. Currently there is over 250,000 metric tonnes of HIGH level nuclear waste being stored around the world. I wonder when people talk the economics of Nuclear power, what costing do they use to "SAFELY" store/manage/protect/guard??? for the danger period of 40,000 to 250,000 years? At a measly one dollar, per tonne, per year, it would be 100,000,000,000, but we all know the real cost would be thousands of times more than that, so when they tell us how cost effective nuclear is, do they even think about nuclear waste, or are they planning to drop it down a big hole, and hope for the best? Goodbye humanity, make sure you destroy all life on earth before you turn the lights off.
richardnail Historical
Scattered presentation, complicated graphs shown for seconds, but more importantly what this guy is fundamentally saying: our living standards have to go down to support the ever increasing world population, it will continue to go down every time more people are added. Moral: your choice, want more population then accept destruction of the environment (this guy said over 20% of the land would be needed for renewables), which will result in a substantial degrading of lifestyle not to mention wildlife habitat. Bottom line, 8 billion humans on this planet is exactly 6.2 billion too many for sustainable living.
Daniel Wasilewski
well, as much as I admire that speech and healthy reasoning, one obvious overlooked question comes to my mind.
What is a total area of Roof tops in UK that housing that population? You could also say... ohh!
Michael Kaemmerling
If the planet got warmer you would need less heat
Éamon Ó Catháin
The problem with biofuels grown abroad for any country is the energy needed to then bring the fuels over sea to the country in which they're going to be burned. I suppose if you're already going to be setting up lines for bringing solar power over long distances you could probably do the same with power generated from bio though..
It should be mentioned that wind can be combined with solar or agriculture on the same land.
1 kW light bulbs?
pOgan pAgan
As an student of electrical engineer, there is a fundamental problem with this. The solar, wind or wave power plants are a regulators not a consistent source of energy. WHY? because for a main source you need a constant input, lets say 100 GW/h and they can't change that must always be 100 GW/h but from all renewable you have drastic changes so they will be used like Dams, yes dams mostly are used for regulating the input in the system not as a main source.
Tony Wilson
To all still commenting this is 6YEARS old, but still some of what he says has not changed, while other stuff has changed dramatically.
The fundamental principals of the graph with energy consumption between 4 and 8 minutes has not changed except that many of the developing are now higher on that graph. At 9.35 "pro-arithmetic" - I get that because as an engineer I am also pro-arithmetic.

TEDx need to have him on again and tell us what has changed and what hasn't.

We know that both wind and solar have gotten cheaper and more efficient.

The table at 10:14 is no longer right - solar concentrating technology has gone ahead in efficiency. And these days there are now 2 distinct concentration technologies - solar and solar thermal and they are very different so you can't simply have 1 line for concentrated solar.

The question is are we progressing enough with renewable technology.
An update for those numbers should be done. Solar is more efficientin 2019. Electric vehicles are becoming popular. Energy consumption is more efficient than ICE.
Worldometers info / world-population
Jack Cornelius
Developed nations should switch to nuclear power if they don't have natural disasters to threaten their facilities. But they'll have to police the use of Nuclear to prevent it's spread to nations that can't safely use nuclear power. The last thing the people of Africa needs is radiation problems from nuclear waste and meltdowns.
Phew!! It's a good thing GW isn't real.
Dalton Agrônomo
The future of cars is electric.

I live in Brazil.
Morten Skogly
What about hydro? Must be measured in m3, not m2? Biogass is another great solution, from landfills, agricultural and other organic waste.
Moonette Wolfsong
Great speech.
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Why is VENEZUELA a CATASTROPHY? - VisualPolitik EN A reality check on renewables - David 8 months ago   09:40

It wasn’t so long ago that Venezuela was the wealthiest nation in the entire of South America. Today, half of their population lives in extreme poverty. So, the question is… How did they end up there? What did their government do so wrong to destroy an economy in so little time? Today, we are gonna tell you the story.

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