“Bottled water is R3 to R20/litre. Our water costs at most about R2,20/litre during amortisation of the capital expense. Once amortised, you’ll be paying around 70c/litre.”
Energy consumption is not insignificant, however. A 100-litre/day unit consumes about 1,5kW of electricity, or a little less than a domestic kettle.
The water produced by Cirrus’s AWG technology is slightly alkaline, he says. Filters remove particulates, and hydrogen sulfide — the gas that causes acid rain — in South Africa’s atmosphere is so low it doesn’t have an impact on water quality.
For peak production, relative humidity must be above 40%. In arid areas, it will often fall below that level during the day, but at night, when the temperature is lower, humidity rises, even in deserts.