The total fixed cost of conventional still is about F = 103 $. To obtain the average value of the cost
of distillate output it is assumed: n is the expected still life time, V is the variable cost, C is the total
cost, where, C = F + V. Assume variable cost V equals 0.3 F per year (Buongiorno et al, 2009), and
for the expected still life 10 years, then C = 103 + 0.3 × 103 × 10 = 412 $ where the minimum average
daily productivity can be estimated from the analysis of different experimental data, and it is
assuming that 2.5 l/m2 a day, Assume still operate 340 days in the year, where the sun rise along the
year in Egypt. The total productivity during the still life =2.5x10x340=8500 l. Cost of litter from
conventional still = 412/ 8500 = 0.048 $.