Design & Nature Reimagined: Mimicking nature to help us store and use energy
Today I wanted to highlight innovations with energy. Although we all likely know about renewable energy by now: wind, hydro, solar, and even nuclear energy, one of the ongoing problems we've had for moving toward new energy is being able to store that energy in a battery. Today I wanted to look at opportunities for understanding how nature stores energy and how we might mimic that with our own technologies.
What is biomimicry?
Biomimicry is when we use natural design to inspire human design. There is more biomimicry around you than you might think! Velcro is a common example of biomimicry; which were designed after burrs that stick to your clothing. A more recent example is a paint that mimics the texture of a lotus petal. Petals of the lotus flower have a texture that wicks away water in a way which allows the petals to be cleaned.
Why energy storage for renewable energy is hard
First of all, storing energy is expensive and would take up a lot of space. And when we say storage, we aren't just talking about batteries, although that's one piece of the puzzle. The types of storage we're talking about is generation, transmission, and distribution. Generation storage means we hold the energy (capturing heat from the sun) store it in a different place (like in molten salt), and then using that energy later when we need it (at night when the sun goes down). If you've got the time, read more about thermal storage with molten salt. It's absolutely fascinating.
Transmission storage means that we can hold onto the energy source and then release that source at a later time when we need the energy. Hydro energy uses this technique by pulling energy from pumping water, and then when there is enough power generated, they can dam the water to reduce energy general. Then, when they need more, they release the water and transmit the energy out. Distribution is the third option for storage, and this is what we see in batteries or flywheels. Flywheels basically build up energy by speeding up their rotor. To release that energy back into the grid, the rotor is slowed down, which release energy and allows it to flow out; in this case it flows out into the grid for, you guessed it, distribution.
Additionally, there is a general problem with supply and demand. Since renewable energy is a supply that changes day by day (a sunny day vs. a cloudy day), finding a way to reliably store and serve it up is important. Finding ways to solve for this requires keeping a balance between supply and demand. Plus, the further out the houses are from the central storage, the more energy it takes to send out that stored electricity.
In recent years there's been progress on solar batteries, and you're able to get solar battery storage for your own home. That leads to the idea that we may have a more decentralized energy system, or perhaps backup storage as we go forward.
Biomimicry for energy storage
So even though we do have some solutions for energy storage, we're still in need of more options. That's where biomimicry comes in. How could we mimic nature to provide more options for renewable energy storage? And not just provide more options, but also improve on existing technology?
One possibility is to mimic the fractal structure of swordfern leaves to provide more storage capacity. This means that we can expand the capacity of existing batteries by employing a new pattern.
We can even mimic butterfly wings to get solar panels to heat up more and produce more energy. That means that the same surface area can ultimately produce more energy!
A final option, which seems like a long way off, but is particularly fascinating to me is biomimetic photosynthesis. When a plant takes in solar energy, it's able to store that energy for later use. A great example of this is deciduous trees. These trees soak up sun throughout spring and summer, then, in fall, their leaves change color and drop. Without leaves, they're not able to photosynthesize and create energy on demand, so how do they stay alive? They go into dormancy and store their energy. In the spring, the tree is able to push out these stored starches and sugars to create new leaves and begin its growth cycle. So how can we find a full lifecycle for energy that mimics photosynthesis?
Artificial photosynthesis is one possible future. If we can get store energy from light in a form that is not starches and sugars (carbohydrates), the energy produced would be much more efficient, so we have to figure that out first. Since photosynthesis is reliable, but not particularly efficient, we need to figure out how to optimize it if we were to use artificial photosynthesis. For artificial photosynthesis to become viable, we would need to get between 5 - 10% efficiency.
From this idea, there is also the potential to turn carbon dioxide into a usable fuel. Currently this is a theory, but one that can be experimented on and explored. I personally think the potential for plants to teach us new ways to interact with the world around us in quite huge. Plants live on a different lifecycle than most humans and animals, but are organisms in their own right. So what new things could we learn from them?
That's all I've got for you today. To end, I'd like you to take a moment to look at one of nature's best energy creation and storage mechanisms—the leaf.