# Reduction of Dust on Solar Panels through Unipolar Electrostatic Traveling Wave
## 3 Electrode Design
### Cost Comparison  
The cost of cleaning PV panels with de-ionized pure water was determined for the 1 MW SPP field in the District of Bolucek of Sanliurfa province in Turkey.  
The cleaning process has the requirement that the PV panels should be cleaned at least twice a year during the life-time of the plant to prevent the loss of panel efficiency going beyond the scope of insurance. The total cost of each clean, excluding the cost of the tractor, from Table 2 is \(\copy\)425.00, giving an annual cost of \(\copy\)14,850.00 for cleaning the panels twice per year. The tractor costs are excluded as it is considered to be within the initial investment cost. This approach also results in a significant waste of water.  
With electrostatic cleaning, the main running cost is the electrical energy consumed by the panels. Each M2 panel working with 4 channels will consume 1.33 A at a frequency of 1 Hz and a voltage of 11 kV, and 0.33 A for 1 channel. Working 8 h a day will consume \(8\times 24\times 0.33=63.36\) Wh of energy at a voltage of 24 V. This results in an energy consumption of 30 \(\times\) 63.36 = 1900 Wh per month and 22,800 Wh annually. The power plant has 4800 panels, and a unit of electricity is priced at 0.07 \(\copy\)1/kWh, according to the EMRA regulations. This results in a total approximate annual cost of 4800 \(\times\) 22,800 kWh \(\times\) 0.07 \(\copy\)1/kWh = \(\copy\)660. The M2 design is 50% less expensive than tractor cleaning. Electrostatic cleaning is less expensive than cleaning with water and its derivatives, saves water and increases the output power of the PV panel.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Product Used** & **Amount** & **Unit** & **Unit Price** & **Total Amount** \\ \hline Cleaning Tractor & 1 & & \(\copy\)20,000.00 & \(\copy\)20,000.00 \\ \hline Tractor Diesel & 100 & L & \(\copy\)0.80 & \(\copy\)800.00 \\ \hline Cleaning Lady & 2 & & \(\copy\)350.00 & \(\copy\)700.00 \\ \hline Cleaning solution or pure water & 395 & L & \(\copy\)15.00 & \(\copy\)5925.00 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Cleaning costs.  
Figure 13: M2 model: (**a**) Before cleaning; (**b**) After cleaning.  
Turkey has 589 SPP, which includes 39 licensed and 550 unlicensed power plants, with further large power plants, such as the 1300 MW solar power plant being built in Konya, being built. The cost of cleaning a 1 MW solar power plant using traditional cleaning methods is \(\ell\)14,850.00 when performed twice a year, with a total of 395 L of solution and pure water being used. A 1300 MW solar power plant will use approximately 1300 \(\times\) 395 = 513,500 L. Moreover, these large power plants are often located in areas with water shortage; electrostatic cleaning is to be recommended in such places. Electrostatic cleaning is expected to become widespread in the future due to lower cleaning cost, time-saving, efficiency, water saving, and increased output from the PV panels. This is even more important after Turkey was placed in the group of countries experiencing water problems [47], and it becomes essential to implement water laws [47] and there is a need to introduce cleaning systems that do not require water.