In Barry Brook’s open forum debating “Do climate sceptics and anti-nukes matter?“, chemist/metallurgist “DV82XL” offers up a well-reasoned summary of why wind and solar are largely irrelevant to our goal of reaching a carbon-intensity of zero by 2050. In 550 words this comment is so tightly written that I will not attempt to abstract. The author does not discuss the gating principle that only “cheaper than coal” energy sources will contribute materially to our zero-carbon goal. That argument was already made in Barry’s parent post.
Marcus â€“ Absence of a decent storage technology means we canâ€™t really time-shift electricity demand. When more electricity is needed more power plants have to be running and feeding power to the grid in real time. Thereâ€™s no way to run plants at night and store the generated power for daytime use.
Transmission losses mean our ability to space-shift demand is limited, too, though not as severely. Electricity-intensive industries (the classic example is aluminum smelting) need their own dedicated power plants nearby.
The combination of these problems means that household energy conservation is mainly a way for wealthy Westerners to feel virtuous rather than an actual attack on energy costs. Household conservation slightly decreases the maximum capacity needed locally where the conservation is being practiced, but has little impact further away, where demand has to be supplied by different plants. Industrial efficiency gains are far less visible; but, because the scale of industrial energy use is so much larger, they matter a lot more.
The combination of these problems also means we cannot, practically speaking, aggregate lots of very small flows of electricity into one big one. Itâ€™s not just total volume of energy production that matters, but the energy density available to high-volume consumers at a given place at and at a given time. This may sound like a dry technical point, but it has huge and nasty implications.
One is that the most touted forms of â€œalternative energyâ€ and are largely useless. Solar and wind power are both time-variable and low-density. Lacking good ways to time-shift and aggregate electricity, means you canâ€™t count on them to run factories and hospitals and computer server farms. The best you can hope for is that they can partially address low-density usage applications, as they have done in the past.
In the real world, there are only four base load sources that matter: coal, oil, hydropower, and nuclear. What they have in common is that you can get lots of energy per gram out of the fuel, thus lots of both energy volume and energy density out of one power plant.
Both economic arguments and historical evidence tell us that you canâ€™t have an industrial civilization without a fuel that has an energy density at least as high (and thus a cost per unit of energy as low as) coal. Higher density is better, because it means lower cost. Those costs are not denominated just in money; low-density energy sources are more labor-intensive to operate and that causes more illness and death. Compare annual deaths from coal mining to annual deaths in the petroleum industry to the annual deaths associated with nuclear power; the trend is dramatic and favors higher-density sources, even if one ignores chemical air pollution entirely.
Nothing on offer from advocates of low-density â€œalternative energyâ€ even comes close to coal as an industrial baseload source. let alone oil or nuclear. Ethanol and hydrogen look like it, until you consider life-cycle costs; basically, making either costs a lot more than mining coal, both in money and in input energy.
For fixed-location power plants, nuclear is the clear winner. Coal and oil have lower density and serious pollution costs. Renewables cannot produce the power we need.