A desalination system has been designed and fabricated. The system consists of a single
slope solar distiller coupled with a solar water heating system. The Solar water heating system is
working as a thermal storage system. Solar water heating system is used to collect the solar energy
during day time and store it in a thermally insulated water tank. This energy is used as a heat
source, when required, for the distiller. Another conventional solar distiller, utilizes only the solar
energy as a heat source, has been used for comparisons with the modified distiller. Experiments
have been carried out during the whole day around the four seasons. Additionally, the effect of
adding Zinc Oxide nanoparticles with diameter 23~28 nm to the working fluid of the thermal
storage system has been tested. Nanoparticles have been added with two different volume fractions
of 0.05% and 0.1%. The results showed that, the enhancement in the productivity of the
conventional distiller ranges from 46.8 % to 105.4 % with average 67 % around the year. For the
storage system, the daily efficiency was 48% without nanoparticles, and, it is equal to 50.7% and
51.2% for 0.05% and 0.1% volume fractions of nanoparticles, respectively.