The best shape for a piezoelectric tree that harvests energy from rain?

Question

This question is the second part of my previous question about piezoelectric plants. In summary: The plants on my world generate electricity from kinetic energy (piezoelectricity) instead of or paired with photosynthesis. The plants are hollow to resonate vibrations and absorb more energy this way. They grow in areas with frequent tectonic activity or with sufficient wind or rain. There are many variants of plant each specialising in one or more energy sources. In this question I'll be asking about rainfall as their power source. Also for the sake of the question just assume the biological process works.

As we all know, plants grow in the direction they are getting light and nutrients from and are also optimised to grow shapes that absorb efficiently. Leaves are wide and flattened to collect sunlight and exchange gases easily. Branches are fractal and grow in the golden angle, this angle promotes adequate ventilation of the plants and is the optimal arrangement for light absorbance. Tree trunks are solid and roots are also fractal to absorb as many nutrients as possible and keep the plant firmly attached to the ground.

How would these plants be shaped to get the most energy from rainfall?

Answer 1

You want to harvest energy from rain & what's the best shape?

Looking at it mechanically I'd say a bowl.

With a bowl you can harvest the kinetic energy of the rain as it strikes the surface while gathering it & then run it off to a lower elevation & harvest further energy by standard hydro electric methods.

This reservoir would essentially be an energy store you can tap during times of low rainfall if needed.

That's easy.

For a 'tree' the 'trunk' (aka bole) might form this bowl, some form of spring loading could capture compression energy as the weight of water in its 'bowl shaped bole' increases then once full runoff tubes lined with some form of vegetable turbine analogues opened to drain it, the branches should be angled up around the rim of the bole to increase the surface area over which rain is caught & its leaves on them angled to channel rain into the bole, the leaves could also collect energy from each raindrop impact through the motion imparted to the stalk & you might expect a layered structure to the leaves & branches to catch runoff from those above.

That's the large physical structure, also easy.

But what structures & bio chemical methods a tree might use to capture, store & convert this mechanical energy for growth is another matter entirely that I'm having difficulty envisioning.

Potentially a whole three other question?

So I'll have to end with a frame challenge of sorts & ask you what known chemical processes you think might be used to capture this mechanical energy & store it for use by a plant?

Because off-hand I can't think of any.

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[Ah! Your prior question has the answer to that does it?]

[I'll go through it's links & see if I can find it, will edit when I have]

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Hmm.. I think you may have misunderstood what 'Electric bacteria ' are & focused overly much on the word electric, they're anaerobic organism that 'breath' metals // that 'electric' part of their name only seems to be a nod to the fact that they use different pathways than normal for the intake & excretion of electrons in more familiar types of metabolization // I don't think it means what you think it does?

If you haven't misunderstood it then I have of course :) after all my reading hasn't been that extensive.

Answer 2

A thick center with thick but short branches extending from it. Those branches will carry very long, thin and tough twigs horizontally with a small slope upwards and a large leaf at the end. The leaf's edges will face downwards and the leaf will twist downwards faster than the twig when hit by rain.

The length means a single raindrop can create a lot of movement across a single twig which increases the energy gained. The upwards slope helps it return to its original position and the leaf's movement when hit by rain prevents an excess rain to break off the twig or leaf.

Answer 3

The leaves should be arranged in such a way that every droplet will trickle from one to the other, maximizing the harvested energy, by intercepting the energy involved in each jump and minimizing the losses to drag.

Answer 4

I think that any energy gained from rain would be far outmatched by what can be gained from the wind. 2 meter of rain per year is a really large amount but insignificant compared a constant light breeze.

A grass type of shape would do well to harvest from wind. For a larger plant you could imagine something like a weeping willow. with long hairlike strands falling down from branches.