What this work is about, in plain words
How much microalgae biomass can in principle be obtained under sunlight in Sevastopol in different months? The authors measured solar radiation over a season and calculated the upper limit of the yield.
In industry, microalgae are most often grown in open ponds under sunlight. To design such a production, one needs to understand how much light reaches the culture surface in different months and what yield it can provide. The authors set out to measure the incoming solar radiation and estimate limiting productivity for Sevastopol conditions.
From September 2019 to June 2020, the irradiance at the pond surface was recorded by an automatic sensor of the authors' own design. The readings were converted into the energy of photosynthetically active radiation, taking into account the solar spectrum at different sun heights. The limiting yield was then calculated from the average calorific value of the biomass and typical photosynthetic efficiency.
By the authors' calculation, the limiting yield ranges from 133 g of dry weight per square meter in December to 824 g in June. In winter, sunlight contains more red and fewer blue rays. The measurements are close to reference data for Sevastopol.
These values can be used as a guide when designing microalgae production in southern Russia.
Limitations. This is a calculated upper limit, not the yield of a real installation. The authors stress that in practice it will certainly be lower: part of the light is reflected and absorbed by the cover, and growth also depends on other conditions.