REFERENCE
[Outdoor and Indoor Cultivation]
(Everyone dreams of cultivating using sunlight, but...)
Basically, most businesses who start cultivating algae start with outdoor cultivation.
After all, everyone dreams of using cost-free sunlight at first.
I myself also tried outdoor cultivation in Shizuoka and Hawaii using an original cultivation device called a biodome because of this motivation.
As mentioned above, it perfectly suppressed adhesion and precipitation, one of the three major elements of algae cultivation, and both the contamination prevention and cooling functions had a fair performance.
So, now I don't have the option to cultivate algae outdoors, but if I absolutely have to do it outdoors, I will use the biodome system without hesitation.
However, I will probably never try outdoor cultivation in the future.
There are two, or rather three, main reasons why.
First, outdoor cultivation is weather dependent, and even in areas like Hawaii that are said to be warm all year round, the weather plays a major role, including temperature issues, cloudiness, and rain.
The fact that it is difficult even in Hawaii also means that there are almost no suitable locations on Earth.
In Japan, the only place where cultivation can be done outdoors is Okinawa, but since Okinawa is also in the path of typhoons, cultivation itself is difficult at certain times.
The second reason is the difficulty of eliminating contamination.
It is no exaggeration to say that this is impossible to begin with, and no matter what system is adopted, the things being grown are plants that are invisible to the naked eye, and the contamination that gets mixed in is also microscopic creatures.
The current state of contamination is never made known to anyone outside the company, so even if it appears to be going smoothly from the outside, in reality it is either a fatally dire situation or a fairly good situation.
Even if the cultivation went smoothly in the early stages of the installation of the equipment, at some point contamination occurs, and once contamination occurs, it is almost impossible to eradicate, and it usually gets worse day by day.
In particular, the open pond method allows not only microorganisms but also anything to be mixed in, and if it rains, the culture solution will be diluted and will be wiped out by heavy rain.
The third point is that, although it is very modern, outdoor cultivation cannot be used to reduce CO2, which is a problem that algae cultivation will have to solve in the future.
The biggest reason why outdoor cultivation is not suitable for reducing CO2 is the reality that outdoor cultivation is extremely selective about the location of its implementation.
CO2 is emitted from all over the world.
And in order to have algae absorb the emitted CO2 and convert it into oxygen, an algae cultivation factory must be located adjacent to the emission site.
It would be meaningless to take the time and energy to liquefy the emitted CO2 and transport it to other areas while emitting CO2.
In addition, outdoor cultivation requires a large site area because the only light source is sunlight.
There is not always a place for that much around the emission point.
Therefore, when using algae cultivation to reduce CO2, it is essential that it is indoor LED cultivation using clean energy.
In addition, as mentioned above, outdoor cultivation is not stable and does not have the function to efficiently absorb CO2, and more than 90% of the injected CO2 is directly discharged into the atmosphere.
When I was culturing in Hawaii, I had no time to think about reducing CO2 at all. I was desperate to prevent all the algae from being wiped out by contamination and obtain biomass, so wasting CO2 was a secondary concern.