Algae biofuel has definitely been a thing that people have tried over and over again and it hasn’t happened after a few decades so presumably there is some issue with commercialization.

Wikipedia claims algae has very high water requirements (>600L of water for 1L of fuel) https://en.m.wikipedia.org/wiki/Algae_fuel

> 600L of water for 1L of fuel

Is this actually the problem or is there other factors? A lot more is needed for 1kg of beef or certain crops.

I live in the tropics and water usage is just never an issue and if it was they'd actually store some of what falls from the sky. Truly doubt that water is the real bottleneck here.

edit: From the wiki page

    Among algal fuels' attractive characteristics are that they can be grown with minimal impact on fresh water resources, can be produced using saline and wastewater

"Can be" != commercially viable.

Algal systems are ecosystems, and artificial ecosystems are (ironically) prone to collapse. It's like waking up one day and discovering all your houseplants have died, except it's a thousand tonnes of now-dead gunk in your algae bioreactor.

Doesn't matter since you want to dump the gunk somewhere anyways. Just dump it and start over.

Losing entire batches of your product on a regular basis is pretty bad for a commercial product

It is not lost, just a little more dilute than usual, and the gunk is not the end product, just a step in between. It is like prematurely harvesting grass. You get shorter stalks, and some extra work, that is all.

Extra work can make a difference if you are trying to get to competitive with fossil fuels and electricity.

It's not the loss of the product but the process; you have to start it up again. Like accidentally killing your sourdough starter.

Maybe Elon Musk suspects that effective algae biofuel production is a strong candidate for his 100M price, which would benefit SpaceX greatly. Maybe even feasible on Mars, in artificial atmosphere there.

Im proposing a conspiracy theory here, but the basically all of the world's most profitable companies are involved in fossil fuel production. They definitely have an incentive to not want this technology to thrive and their leaders have a lot of influence and money.

The retort to this theory would be that a company with a lot of resources could simply invest in the new technology.

But with the level of lazy corruption in the world it seems possible that these entities might be suppressing the technology somehow.

On the other hand if one of them cracks algae fuel production they get to make an awful lot of future money off all their existing fuel distribution infrastructure. Iirc several of the big oil companies were at least experimenting with it 10 years ago.

It doesn't take a huge amount in the way of active suppression: hire a some of the brightest industrial chemists and pay them well to work on your stuff instead of untested, unprofitable algae technology. Other smart people will similarly work on financial derivatives or cost-per-click optimisation instead of money-losing algae.

It's not a conspiracy, it's just capitalism chasing returns.

As far as my understanding goes, bio processes using whole organisms/cells like algae/bacteriae/fungi (as opposed to processes using a small set of enzymes or plain chemical processes using catalysts) inevitably come with the disadvantage of heaving a huge overhead. The organism/cell is a complex machinery where there's hundreds of pathways and chemical reactions running that are necessary to just keep the organism alive. Only a fraction of the energy input comes out in the form of the desired molecule. Most is dissipated as heat.

Maybe not the worst analogy would be the comparison between two systems for mining cryptocurrency: A, a specialized chip (ASIC), specifically designed to efficiently run the required algorithms and B, a general purpose PC that has all kinds of peripherals (monitor, keyboard, mouse, hard drive, ...) attached to it, drawing additional power that doesn't benefit the mining. B of course will never beat A in terms of energy efficiency.

So I'd guess if there's a purely chemical/enzymatic process that can do the job, it'll be that, rather than a whole cell/organism.

> In theory would only need sunlight and water to operate ...

Don't forget minerals.

Why wouldn't you use wild type algae, they are already quite efficient in producing biomass?

That is not the same. Then you need nutrients for cell replication as well (amino acids/protein, minerals, vitamins). But if you just collect secreted hydrocarbons from algae you in theory only need sunlight and water, and a little nutrients to maintain the cells. Maybe one issue is that most algae replicate very often, maybe once a day. I used to do bioengineering of an algee (Chlamydomonas) in my Masters