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Comment by Veedrac

2 days ago

3% GDP over a single decade is certainly not a trivial amount, but it's worth noting the comparison here is spending more than that every year forever.

Similarly, 100 TWh sounds like a huge number, and it is, but it's like the equivalent capacity of one base Model 3 per 6 people globally. It's a lot in absolute terms, for sure, but it's by no means a crazy unachievable quantity of battery for a family of 6 to use.

If I wasn’t clear: 3 percent of gdp is the ballpark perpetual capital cost with present technology and a 20 year storage system life. Just capital costs and just storage. Versus all of energy being roughly 5pc of global GDP now.

That is assuming we can hit that scale in the next couple decades and that nothing happens to push up costs with increased scale. More likely is a moderate cost increase, but who knows? Putting all our eggs in the battery storage basket is not great.

Just a few percent more stable base generation in the mix would greatly reduce the amount of storage needed and open more options (e.g making power to gas more reasonable)

It may be cheaper overall; it may not be. But even if you think this is modestly costlier, reducing risk and volatility of outcomes is something that one often chooses to pay for.

  • I find this hard to believe. Let's math it. Let's put grid storage at $200k/MWh, or about 4x current battery prices. Let's keep it at that level for sake of argument. Let's very pessimistically say we need to replace 50% of storage every decade, and again for sake of argument let's say replacing the batteries costs the whole 4x (eg. no reuse of material or converters or grid connections). So the math there gives $1T/y for storage.

    Idk, it seems like even pretty pessimistic arguments with frozen costs and early retirements suggest this is cheaper than the numbers you gave.

    > That is assuming we can hit that scale in the next couple decades and that nothing happens to push up costs with increased scale.

    This strikes me as odd to posit about a technology that has had a steady 23% cost reduction per doubling over the last 6 decimal orders of magnitude.

    • Current prices of installed systems at peak scale are 150-350k/MWh.

      Replacing it all on a 20 year cadence seems like a reasonable assumption.

      Arguments assuming a positive return to scale 4 orders of magnitude out may be true— or may be unduly optimistic. I don’t like to have too much faith extending the lines too far off the right of the graph. When that is required, I want whatever margin and ways to reduce risk as possible: which is why I would like more nuclear in the mix. A grid with 12pc nuclear and the rest renewable (so about 3-4pc of nameplate power nuclear) would require much less over provisioning and storage.

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