The production power of the solar panel is one of the parameters for calculating the efficiency of the solar system. However, these approximate calculations are very useful and can be effective in estimating the approximate costs of a solar power system. This calculation is very simple and it is enough to divide the figure obtained from the number of watt hours per day by the figure corresponding to the worst case of monthly solar radiation intensity. Installing solar panels on the roof of your home is very effective in reducing the cost of electricity consumption and not only increases the value of your home, but also significantly reduces the carbon dioxide in the air. Solar energy is clean and renewable; plus, it's very affordable in Iran with lots of sunshine. In the modern world, the population is increasing, and as a result, the consumption of energy, especially non-renewable energy, has increased. On the other hand, fossil fuel resources such as oil and gas are decreasing. Therefore, the use of renewable energy such as solar energy, wind energy, etc. is a necessity.