The Green Energy Transition Blindspots | Olivia Lazard | EDU2022 

Excellent talk. Thank you for sharing Olivia’s important work with a wider RU-vid audience.

Unfortunately, and contrary to her assertion, Olivia's discussion does not actually start with the physics. In physics one of the fundamental tenets is that if you compare two, or more, things you have to compare apples with apples, as they say. Her statement; "... what this means is that the power density contained in one unit of coal gas and oil is greater than that produced within one solar panel or one windmill." Comparing a unit of coal with what the area of a solar panel is not comparing apples with apples. It's a bit like someone saying you can make more apple pies from a bag of flour than you can from an apple tree, which clearly doesn't make sense, although this possibly is not the best analogy. Furthermore, from the graph it is clear that the energy per unit area it is describing for fossil generation is land required for a power generation station, but forgetting the fact that the fossil energy needs to be extracted, which would be far larger, will be possibly hidden underground. Because of this, to correctly calculate the power density of fossil fuels then you would need to know the thickness of the coal seam, the depth of the oil field etc. and you have to compare the two technologies over the same time scales. For example, solar panels in regions with good solar resources have an average power density of around 50 W/m², a 1m² by 1m thick seam of coal weighs up to about 1.8 tonnes. Accordingly, if you had a 1m thick coal seam, each 1m², if burned in one year, would have an equivalent energy density of approximately 1,600W/m². However, you can only mine that coal once but the solar panel will keep giving its 50W/m² for about 25 years. So for a fair comparison you would have divide the coal value by 25, which gives you 64W/m². However, another one, if you're using coal to make electricity only about 40% of the energy will be converted to electricity whereas solar panels and wind turbines yield their power directly as electricity, so the true coal energy density would then be about 25W/m². I'll leave somebody else to do the oil and gas analysis, and comparisons with different coal scene thicknesses. However, again, solar and wind produce far fewer carbon emissions then fossil fuels so we should also take into consideration the amount of land required to draw down the CO2 produced by the fossil power station. So when you do a fair, full system analysis it would appear that the power density of renewables is probably significantly better than fossil fuels, taking all aspects into consideration. This shouldn't be overly surprising considering that fossil fuels originally started out as biogenic material, plants or animals, which can harvest energy from the Sun far less efficiently than a solar panel or a wind turbine. (yes, a wind turbine is solar energy, it's the sun's energy that makes the wind blow). I've also watched Olivia's TED talk, and whilst I would agree that quite a bit of what she's saying, mostly the socioeconomic bits, parts of it similarly lacked scientific/physic]s rigour. I've now started listening to the next bitter this talk on mineral extraction in which Olivia States; "To get 10 g of copper for example we need to move and extract on average 1 ton of soil" This sounded wrong as soon as I heard it, it would mean they were mining copper with a concentration of 0.001%, or 10 PPM, which even though I don't have any real knowledge of copper mining struck me as being too low to be economical. So I did some quick internet searching. As far as I can make out the mine she's showing is probably the "Bingham Canyon Mine, more commonly known as Kennecott Copper Mine", in Utah. From some rough calculations, based on the size of the mine and the annual copper yield, it would appear that the, 10g copper per ton of soil, calculation is based on taking the total excavation of the mine, (labout 25 to 30 billion tonnes) and divided it by one year's copper production, instead of the 19 million tons of lifetime production. The calculation then works out at about 680 grams of copper per ton of material (which almost certainly won't be soil) removed. However if we are just talking about the actual copper ore itself then apparently: "Copper concentrate generally contains 20 to 30 per cent copper; for this example, 270 000 tonnes per day of mined material may produce 1 750 tonnes of copper." Olivia has far more impressive academic achievements than I do, but hers are in a socioeconomic sciences rather than the physical sciences or engineering. Furthermore, the fact that mining copper with a copper content of just 10ppm (10g/tonne) doesn't immediately ring alarm bells as not being economically viable, suggests social economic degrees don't embody rational thinking. At 10ppm that would make copper about 10 times more abundant, and hence 10x cheaper, than gold (≈$30M/t), so it should be costing over $1M/tonne, not about $8K/t.

Another bit of unscientific science "The international energy agency tells us, for example, that with the current level of innovation an electric car requires six times more mineral inputs than a conventional car". What about the 'mineral' fuel and engine lubricants a conventional car uses in its lifetime. For a diesel SUV you're probably looking around 10 times its weight in fuel over its life. For an EV run on renewable or nuclear electricity, which ultimately they will be, the equivalent mineral input will be miniscule.

Let's call them wind turbines, not wind mills. Nothing is being milled here.

The very serious lady has some important things to say. My question is: after the graph ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-98j9Utld7tU.html why would we build anything else than nuclear, to get into all the troubles with wind and solar mentioned later? Why not obvious point, but 20 minutes of rambling?

I am at sixth minute. The very serious lady hasn't told anything substantial yet.