This process would have benefits where high density energy is needed, hydrogen powered container ships being a popular plan of mine.
But if you don’t have space constraints, involving a hydrogen fuel cell only adds inefficiencies. Most fuel cells are in the 64-80% efficiency range, which the theoretical max being 84%. This might be worse off than the PV->battery->use pipeline that we’re used to.
The quote “Natural photosynthesis is not efficient because it has evolved merely to survive so it makes the bare minimum amount of energy needed – around 1-2 per cent of what it could potentially convert and store” makes no sense to me; plants are usually in massive competition for access to light, so in what sense is there no need for it to be more efficient?
As a hypothesis (because I’m not a biologist) it might be important to optimise for other things at the expense of efficiency. Disease resistance, for example. Or perhaps absorbing more sunlight will cause them to overheat (is that why the leaves are not black?)
Unless we know all the factors involved in 'survival' we can't assume that it's enhanced by greater energy efficiency. The latter may be counter-productive in ways that are not immediately obvious. Given the state of inefficiency of conversion that's evolved (survived), clearly there has not been a need for efficiency besting 1-2 per cent.
That's not generally not how evolution works. Sure, a plant will do fine with the current efficiency of photosynthesis, but intuition would tell us that a plant would do more fine if its leaves were more efficient. It would grow faster, have more or better seed and would generally outcompete other plants of its species.
That the efficiency is not higher than this leads us to believe that either:
- there are strong evolutionary imperatives to not raise the efficiency any further (ie: "there has been a need not to", rather than "there has not been a need to). This could be due to a lot of reasons; oxidative stress, a plant's 'desire' to have a large leaf surface, a tendency to dry out the soil too quickly, etc etc.
- With the current 'design' of chlorophyl, it is not possible to increase efficiency further, and it's quite hard to get out of the local optimum.
In full sun a plant can absorb far more light than it can handle. Apparently one of the little tricks of chloroplasts is how they shunt that power away without sustaining damage. Could we just do something with that power?
It’s a bit like turning the rotor blades when the wind is too high to keep the thing from ripping itself apart.
But imagine if you could make a turbine that generated tons more electricity in a gale force wind. Think what you could do with that much concentrated power.
In both cases it's a straightforward cost-benefit tradeoff: sure, you can build a turbine that works in gales. But they're rare. So in practice the turbine design is tuned against a statistical model of expected wind speeds to deliver the best $/kWh ratio over its design life.
> Think what you could do with that much concentrated power.
That sounds more like a headache (now you have to uprate the whole power-handling systems) than a benefit.
I've not been able to kill the idea of a plant that uses excess energy to create hydrogen which it uses to float its seeds far and yonder. Didn't know that there's already a lot of excess energy that could be used for such a project, though I suspect the knowledge of genegeneering needed to make it happen is a ways off still.
to add to this, I just listened to a podcast called StarTalk [0] where Neil deGrasse Tyson interviewed James Cameron [1]. James Cameron stated the idea for some of the plants actually come from personally scuba diving and seeing some plants react the way they did in the movie (specifically when you touch them move or close up)
James Cameron stated he has been a passionate scuba diver and it was a slight nod to others who may have had similar experiences.
Not hydrogen storage for seed dispersal, but Larry Niven's Known Space series featured Stage Trees. These were plants genetically engineered to be solid fuel rockets. They grew to be quite large, multistage launchers. When they ignited, they dispersed their seeds to other planets.
The biological hardware for producing hydrogen already exists; green plants make use of an oxygen-evolving complex to split water into oxygen and hydrogen, and the hydrogen then goes on to pump ATP synthase.
However, storing hydrogen is probably infeasible for biology. It's difficult to store hydrogen, even using metal containers without it leaking out, because the molecules are so small.
Usually it would be far simpler and cheaper to just use the wind to spread seeds through a variety of methods. Nature tends to "try" to conserve energy (no conscious effort involved but the ones that do so usually win out at a certain point), hence the rarity of high energy mechanisms things like bombdardier beetles or even offensive horns - predatory usage needed to sustain it would be too expensive for misses but defensive usage can be budgetted for better since saving their life is worth a heavy investment compared to death which voids its energy benefit to propagation. Even suicidal maters want their energy to contribute to their offspring.
Granted there are also opportunity costs to everything - rabbits dominated Australia comically despite the widespread deadliness by investing in reproduction and evasion instead of dangerous defense mechanisms.
> High sunlight can raise plant growth rates but can potentially cause cellular damage. The likelihood of deleterious effects is lowered by a sophisticated set of photoprotective mechanisms, one of the most important being the controlled dissipation of energy from chlorophyll within photosystem II (PSII) measured as non-photochemical quenching (NPQ). Although ubiquitous, the role of NPQ in plant productivity remains uncertain because it momentarily reduces the quantum efficiency of photosynthesis.
Optimisation methods tend to get stuck in local optima. I'm sure nature sqeezed out every ounce of possible performance out of the current photosynthesis but that doesn't mean there can't be vastly superior process doing basically same thing but different enough that it won't spontaneously get discovered by evolution in next billion years.
That statement makes no sense to me but neither does the popular idea that species evolve to compete with each other limited only by immediate material resources.
I imagine some mechanism of foresight or conservatism must develope in a diverse population for the population to survive in total. Such a mechanism may have had to be present in the earliest lifeforms or else long periods of accumulating complexity and diversity, seem open to frequent and potentially unrecoverable upheaval, by the temporary competitiveness of mutations fit only for immediate material demands.
I think the particular hypothesis in the following has been rejected, but the article introduces some of the interesting variations in photosynthesis and hints at different evolutionary pressures behind their emergence. To the point about the efficiency of chlorophyll-based photosynthesis,
Chlorophyll, the main photosynthetic pigment of plants,
absorbs mainly blue and red wavelengths from the Sun and
reflects green ones, and it is this reflected light that
gives plants their leafy color. This fact puzzles some
biologists because the sun transmits most of its energy in
the green part of the visible spectrum.
I'd love to know more. If this is as simple as having liquid water pumped through tubing with algae this sounds great. How natural a system can this be? How pure does the water have to be?
Off Topic: ( A question I have in my head for a long long time )
What are the purpose of these PR article from University to other Academic Science magazines? If it was to attract investors or sponsorship, surely companies and individual have other means of access to how to invest or not, and not looking at every magazine / papers / Website announcement.
There are countless battery "breakthrough" and we all know they are at least another 5 years away from commercialise, or in most cases, never. Apart from inner nerds wanted to know, what value do they provide? What purpose do they serve?
In Oxbridge, colleges compete for public exposure because ultimately that’s what leads to donation & to get top undergrads applying who, eventually, will donate £££ to the college once they land a good job. So there’s quite a lot of PR relating to sports & academic achievements.
What’s a bit ironic in this case is that no research is really done at colleges, and grads tend not to be central to college life, it’s really the authors & the research lab who deserve the creds!
> What are the purpose of these PR article from University to other Academic Science magazines? If it was to attract investors or sponsorship
Pretty much this though probably for attracting students too.
> surely companies and individual have other means of access to how to invest or not, and not looking at every magazine / papers / Website announcement.
Sure they do, some have existing relationships etc. But it doesn't follow that this sort of release isn't useful.
For example, I'm in industry and, occasionally, we are looking at something that I believe could benefit from external expertise. Sure I have academic and consultancy contacts but I've also Googled what I'm interested in and found relevant press releases or, more often, papers. A phone call or email exchange has often led to a collaboration or pointers in a useful direction.
Universities are always under pressure to show impact. They need artifacts to show to funders (govt ministers) and demonstrate relevance. The explanation 'our lab turned water into fuel using algae' is generally intelligible, while the Nature reference lends a credibility the intended lay audience isn't intended to cash.
Also, there is some element of just wanting people to be aware of cool stuff that got done.
Universities are primarily there to produce scientific breakthroughs, not bring technologies to market. The value is in undertaking high risk research.
I was working for a very large research institute. They had a large full color magazine with several people on the payroll that noone read. I never got a good answer why we did it, except momentum and everyone has one.
37 comments
[ 2.6 ms ] story [ 64.7 ms ] thread'Their method also managed to achieve more efficient absorption of solar light than natural photosynthesis.'
This process would have benefits where high density energy is needed, hydrogen powered container ships being a popular plan of mine.
But if you don’t have space constraints, involving a hydrogen fuel cell only adds inefficiencies. Most fuel cells are in the 64-80% efficiency range, which the theoretical max being 84%. This might be worse off than the PV->battery->use pipeline that we’re used to.
That the efficiency is not higher than this leads us to believe that either:
- there are strong evolutionary imperatives to not raise the efficiency any further (ie: "there has been a need not to", rather than "there has not been a need to). This could be due to a lot of reasons; oxidative stress, a plant's 'desire' to have a large leaf surface, a tendency to dry out the soil too quickly, etc etc.
- With the current 'design' of chlorophyl, it is not possible to increase efficiency further, and it's quite hard to get out of the local optimum.
It’s a bit like turning the rotor blades when the wind is too high to keep the thing from ripping itself apart.
But imagine if you could make a turbine that generated tons more electricity in a gale force wind. Think what you could do with that much concentrated power.
> Think what you could do with that much concentrated power.
That sounds more like a headache (now you have to uprate the whole power-handling systems) than a benefit.
One problem with floating plants is that dirt and water are heavy.
[∆]https://en.m.wikipedia.org/wiki/Tillandsia
James Cameron stated he has been a passionate scuba diver and it was a slight nod to others who may have had similar experiences.
[0] https://www.startalkradio.net/show/ [1] https://www.startalkradio.net/show/the-spirit-of-exploration...
However, storing hydrogen is probably infeasible for biology. It's difficult to store hydrogen, even using metal containers without it leaking out, because the molecules are so small.
Granted there are also opportunity costs to everything - rabbits dominated Australia comically despite the widespread deadliness by investing in reproduction and evasion instead of dangerous defense mechanisms.
> High sunlight can raise plant growth rates but can potentially cause cellular damage. The likelihood of deleterious effects is lowered by a sophisticated set of photoprotective mechanisms, one of the most important being the controlled dissipation of energy from chlorophyll within photosystem II (PSII) measured as non-photochemical quenching (NPQ). Although ubiquitous, the role of NPQ in plant productivity remains uncertain because it momentarily reduces the quantum efficiency of photosynthesis.
https://en.wikipedia.org/wiki/Photoprotection
https://en.wikipedia.org/wiki/Non-photochemical_quenching
I imagine some mechanism of foresight or conservatism must develope in a diverse population for the population to survive in total. Such a mechanism may have had to be present in the earliest lifeforms or else long periods of accumulating complexity and diversity, seem open to frequent and potentially unrecoverable upheaval, by the temporary competitiveness of mutations fit only for immediate material demands.
What are the purpose of these PR article from University to other Academic Science magazines? If it was to attract investors or sponsorship, surely companies and individual have other means of access to how to invest or not, and not looking at every magazine / papers / Website announcement.
There are countless battery "breakthrough" and we all know they are at least another 5 years away from commercialise, or in most cases, never. Apart from inner nerds wanted to know, what value do they provide? What purpose do they serve?
Pretty much this though probably for attracting students too.
> surely companies and individual have other means of access to how to invest or not, and not looking at every magazine / papers / Website announcement.
Sure they do, some have existing relationships etc. But it doesn't follow that this sort of release isn't useful.
For example, I'm in industry and, occasionally, we are looking at something that I believe could benefit from external expertise. Sure I have academic and consultancy contacts but I've also Googled what I'm interested in and found relevant press releases or, more often, papers. A phone call or email exchange has often led to a collaboration or pointers in a useful direction.
Also, there is some element of just wanting people to be aware of cool stuff that got done.
Universities are primarily there to produce scientific breakthroughs, not bring technologies to market. The value is in undertaking high risk research.