節能、減碳排的理念源自於環保意識及全球氣候變遷而起，有效降低能源消耗量及提高能源再生供給量是目前重要的課題。太陽能發電是目前發展最為快速的再生能源之一，近日核四議題再次喚起人民對環保再生能源的重要。台灣政府為推動再生能源政策「陽光屋頂百萬座」計畫，就是希望鼓勵人民安裝太陽能發電設備，除了分擔台電公司尖峰用電的壓力之外，還可以學習節能、減碳帶來的經濟發展效益。 本文中借鏡發展綠色能源成熟的國家日本、德國為例，並進行家庭用太陽能發電財務分析，透過淨現值(NPV)及內部報酬率(IRR)等方法，企圖使民眾更清楚瞭解綠色能源發展的重要性，期政府提高財務上的誘因，進而採取有力長久的作為，加速鼓勵民眾的安裝意願，共同達成台灣成為永續發展的國家為目標。;“Energy conservation and emission reduction” are a major response to our “environment protection and global climate change” demands, so more effective “energy consumption reduction and renewable energy supply increase” measurements are a highly leading subject in now days. Solar-Energy Power is one of the fastest growing Renewable Energy in recent years, especially in Taiwan when “the 4th Nuclear Power Plant issue” is again awaking people to pay more attention and watching the importance of our current environment protection and renewable energy measurements. ”Taiwan Officials are now advocating “Million Rooftop PVs Program” and subsidizing the installation of Solar-Energy power equipment. The program purpose is to release Taiwan Power Co., pressure in “Peak Season” and get people to learn more about the economic advantages of Energy conservation and emission reduction.In this thesis, Germany and Japan – a developed mature Green Energy populated economy is studied as an example, and Net Present Value (NPV) and Internal Rate of Return (IRR) methodologies are applied and in attempt to get Taiwan Officials and people to better realize the importance of Green Energy so that Officials can motivate people financially and make long-term promotion package for adopting Green Energy Solutions. We look forward to seeing Taiwan achieve National Sustainable Development goal through all of these efforts.