Vietnam saw a big increase in solar energy in 2020, becoming the world's third largest market. The government's support policies, like feed-in tariffs, played a key role in this growth. A study looked at these tariffs in different parts of Vietnam for solar energy. The cost of producing electricity from solar panels was compared to the tariffs. The results showed that in areas with less sunlight, the cost of solar energy production is higher than the tariffs set by the government.