Why do we have to utilize solar energy? (왜 우리는 태양에너지를 사용해야 하는가?) We have heard about renewable energy from mass media or surrounding people. However, we have not heard about the reason why we must use renewable energy. Even in South Korea, really strange rumor is spread that photovoltaic cells generate bad electromagnetic wave and cause water pollution. Hence, these days, the public opinion is n..