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Comment by csours | Hacker News Reader

Q: A big stack of concrete blocks seems to be almost purpose built for the wind (or a gigantic mutant toddler/cat) to push over. Cranes are also extremely susceptible to wind. I suppose the blocks could be engineered to interlock, but the pictures show cylinders. How do they plan to counteract the wind?

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Huh? A big stack of concrete blocks weighing 35 tonnes each seems to me exactly the opposite of being purpose-built for the wind. Maybe if you built it out of feathers then it'd be purpose-built for the wind, but gigantic concrete blocks don't get blown around a lot.

This seems like it'd be much more resistant to wind than buildings, which are hollow.

To me the most fascinating stability question is seismic. Wind is mostly predictable (apart from unusual events like microbursts). It would be easy enough to stack up a storm-stable shape before major predicted storms hit. Seismic stability would need to be considered throughout the stacking / unstacking process.

The cylinders have got to go, however. Stable stackable shapes are a thoroughly solved problem (bricks!), and stack at higher densities as well. Scaling up a press release model from the barrels they used for a real life demo saves very little time or money and implies an absence of familiarity with structural engineering, which will be this concept's #1 critical problem.

As far as the crane goes, the article indicates that "Wind could cause the block to move like a pendulum, but the crane’s trolley is programmed to counter the movement." That actually seems like the most interesting part of this system.

I'm sure they've accounted for winds they expect to encounter on a yearly basis, but "century" storms do happen, just ask Houston TX.

"Houston is experiencing its third ‘500-year’ flood in 3 years. How is that possible?" - https://www.washingtonpost.com/news/wonk/wp/2017/08/29/houst...

They aren't worried about the wind's effect on the stacked blocks, just the ones suspended. If a century storm comes, just shut it all down for a day, everything is stable.

Moving average. Climate change.

Huston got unlucky, but the real worry is the new 100+ year storm, because that will be even more brutal in the changed climate.

Surround it with a hyper-dense mesh of windmills. Now it can generate energy when demand is high, and store energy when demand is low.

The wind problem seems tractable and quite fun to think of different ways to solve it.

Could you dig it down?

By putting it indoors?

That would almost certainly price it well out of the range of even lithium ion storage.

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