Mr.Karthick Munisamy,

Can you tell your research, i wnat know your key parameter and correletion, after that only i can give effective answer to your qustion.

The economic feasibility of any solar still can be assessed primarily on the basis of ‘the unit cost of desalination of saline water’ and ‘payback period’ (np) of the investment made for the solar stills. In this section, the conventional model of techno-economic analysis  is given to evaluate the unit cost of desalination of saline water (UCdw) and payback period. The modified model is presented in the next section.

The cost of desalination of saline water from a passive solar still depends mainly on the present capital cost of the solar still (Cs), interest rate on annual basis (i), expected useful life of solar still in years (n), salvage value of solar still in future (S), average annual productivity in liters (Myearly), and annual operation and maintenance cost (OMC). The cost of land to install the solar still, annual tax and insurance charge (if any), and the annual cost of saline water are ignored here. The OMC includes the annual cost involved in regular cleaning of the glass cover, removal of scaling due to salt deposition on the basin liner and side walls, regular filling of saline water to maintain the level of saline water in the basin, and safe collection of distilled water regularly to avoid contamination.  However, a large variation in these parameters has been noticed in the world due to different socio-economic conditions. A square meter for a single-basin solar still costs about $400/m2 in the USA and the levelized energy cost of solar distilled water is about US$0.03 per liter for ten-year lifetime of the solar still as reported by Foster et al. [24]. Cost analysis of different solar still configuration by Kabeel et al. [22] presents the latest cost comparison of different solar stills studied by various researchers.

Economic analysis parameter [US$1 = Rs.56.00 (INR) and €1 = Rs.68.00 (INR)].

The unit cost of desalination of saline water (UCdw) is the ratio of total annualized cost of the passive solar still per unit area and average annual productivity in liters of the solar still per unit area. It can be estimated using the following relation [23]: (1)where total annualized cost (TAC) of the passive solar still is calculated as: (2)Each factor of Equation (2) is calculated by the relations given in the Equations (3), (5) and (6).

The annualized capital cost of solar still (ACs) is given as the product of the present capital cost (Cs) and capital recovery factor (CRF): (3)where the CRF is calculated as: (4)And, OMC is assumed to be 15% of the ACs as given in Table 1. Hence, (5)

Since annualized salvage value (ASV) is the product of salvage value of solar still in future and the sinking fund factor (SFF), it can be expressed as: (6)where (7)The average annual productivity in L/m2 (Myearly) can be calculated as: (8)where and are the mean daily distillate output per unit area and number of clear days in a year, respectively.

The payback period is the minimum time required to recover investment costs involved for the system. There are many methods for the estimation of it [23]. For simplicity, in the case of solar still, it is assumed that cash flow (CF) is the same for each year. Then, expression for the estimation of payback period can be expressed as: (9)

If the distillate produced by solar still is sold at market price (Sp), the CF can be calculated as: (10)where the is the selling price of distilled water per liter.

http://ijlct.oxfordjournals.org/content/early/2013/06/24/ijlct.ctt048.full