Due to crisis in natural resources and ecological issues, many countries are moving on the road to renewable energy sources. Solar power is the most potential source of renewable energies. Owing to the open sky exposure, solar power generations are highly susceptible to lightning damages. Lightning induced overvoltage in a solar power generation system can harm insulation of the DC cables, inverters and other electrical and electronic equipment in the system. In this paper, the lightning induced over voltage on the DC lines of a large size solar power generation system is calculated. Lightning protection system (LPS) is used to reduce the induced overvoltage. It is found that properly designed LPS can reduce the induced overvoltage to nearly half. To further reduce the induced voltage, surge protective device (SPD) is proposed with the DC lines. The performance of the proposed method to reduce the induced overvoltage is analyzed using Finite Difference Time Domain (FDTD) method. It is found that the proposed method of using SPD in DC lines of the solar PV system can reduce the lightning induced overvoltage significantly.