Introduction

The climate of the Kashan Special Economic Zone, characterized by solar radiation indices, abundant sunshine hours, low humidity, and minimal rainfall, ranks among the most suitable areas in Iran for solar energy development and photovoltaic power plant installation. Meteorological and climatic data analysis underscores that Kashan’s environmental conditions not only favor downstream basic metal industries but also present an excellent opportunity for investing in renewable energy, particularly solar power.

Solar Radiation and Sunshine Hours

• The average annual sunshine duration at Kashan station is approximately 2,928 hours, with an annual sunshine percentage exceeding 65%, representing critical technical parameters for solar power plant construction.
• The months from June to September record the highest solar electricity generation potential, with sunshine exceeding 75%.
• Considering the geographic latitude (34 degrees north), the solar incidence angle in the region is optimal for solar panel installation, enabling maximum utilization of solar energy throughout the year.

Temperature, Frost, and Impact on Power Plant Performance

• The average annual temperature in Kashan is around 19°C, with absolute maximum and minimum temperatures recorded at 48°C and- 12°C, respectively.
• Annual frost days are limited to 39, which is comparatively low within the province, significantly reducing equipment damage risks.
• The substantial diurnal temperature variation, when managed with standard equipment selection and appropriate design, does not adversely affect the power plant’s performance.

Wind Conditions and Their Effect on the Solar Power Plant

• The predominant wind direction is from east to west (45 degrees) with an average annual speed of about 3.3 m/s, beneficial for panel cooling and efficiency enhancement.
• Wind speeds in Kashan are not strong enough to damage panels; however, structural design must account for resistance to occasional severe seasonal winds.
• The absence of destructive winds and severe sandstorms ensures operational stability for the power plant.

Rainfall, Humidity, and Evaporation Rates

• The region’s average annual precipitation is approximately 130 millimeters, classifying it as arid to semi-arid.
• Relative humidity remains below 45% annually, reducing corrosion risks and extending panel lifespan.
• High annual evaporation and transpiration rates (2,300 to 2,600 mm) indicate clear skies, dry air, and minimal cloud cover, favorable for solar radiation.

Climate Classification and Comparison with Successful Global Regions

• According to the Domarten, Ambrže, and Silianov classification systems, Kashan’s climate is assessed as “cold dry” and “dry.”
• These characteristics align with numerous globally successful regions in solar power plant development, such as special economic zones in China, India, UAE, and South Africa, which have transformed into solar power production hubs due to their dry, sunny climates.
• International studies confirm that dry climates with high sunshine hours incur the lowest solar power generation costs while achieving the highest efficiency.

Conclusion and Investment Recommendations

The climatic conditions of the Kashan Special Economic Zone, encompassing solar radiation, sunshine hours, temperature, low humidity, minimal rainfall, and favorable winds, position it as one of Iran’s premier locations for solar power plant development. These factors reduce maintenance and equipment depreciation costs, enhancing the economic viability of solar projects.

Considering global trends toward green special economic zones and successful international experiences, investing in solar power within the Kashan Special Economic Zone is not only technically and economically justified but also has the potential to establish the region as a national and regional model for clean energy development.

References

1. Climatic studies for the revision of the comprehensive plan of the Kashan Special Economic Zone
2. SolarPower Europe, Global Market Outlook for Solar Power 2025-2029
3. Renewable Watch, “Government allows developers of SEZ to deploy solar systems for captive consumption”
4. SEforALL, “Green Industry Special Economic Zones to Catalyze Renewable Energy Manufacturing”
5. IEA-PVPS, Snapshot of Global PV Markets- 2025