What this work is about, in plain words
How much microalgae biomass can at most be obtained under sunlight? The authors calculated this for the area around Isfahan in Iran for different orientations of the illuminated surface.
Light is the main source of energy for algae growth. So the yield in the open air is ultimately limited by how much solar energy reaches the culture surface and what share of it the cells convert into biomass. The authors set out to estimate the upper limit of daily and seasonal productivity for the conditions of Isfahan (Iran).
The calculation is based on the daily course of solar radiation, the average calorific value of dry algal biomass and different values of photosynthetic efficiency. Different orientations of the illuminated surface relative to the sun were considered.
By the authors' calculation, at a photosynthetic efficiency of 5 % the limit is about 38 g of dry biomass per square meter per day, and at 15 % about 114 g. Over the period from 21 March to 21 September, at an efficiency of 15 %, the limiting yield reaches about 18.5 kg per square meter.
Such estimates help to understand what yield is achievable in principle in a given climate and to choose the orientation of the installation.
Limitations. This is a calculation of the ideal upper limit, not the yield of a real installation. In content, the work is close to an English-language article by the same authors in the Iranian Journal of Fisheries Sciences (2013).