This research explored several energy solutions for Nigeria in order to have a long range and sustainable power sector. In the research, four deferent scenarios such as Business as usual scenario (BAU), Mild renewable energy scenario (MRES), Extreme renewable energy scenario (ERES) and Total green energy scenario (TGES) were developed using a computer tool kit LEAP from 2018 to 2050. The reference scenario was developed base on governments plan for renewable and sustainable power sector, while the three alternative scenarios were developed base on different policy settings in order to examine the reserves, demands, supply and emission impact of each of the scenarios. Also, the research compared some important energy policies existing in Germany with Nigeria. The results obtained showed that at 2050, the business as usual scenario has the highest energy demand with about 1.3 million GWh , while the total green energy scenario has the least energy demand with about 0.9 million GWh. For the greenhouse gases, the business as usual scenario again has the highest level of greenhouse gases (GHG) with about 231 million ton carbon dioxide equivalent (tCO2e) while the total green energy scenario has the least level of greenhouse gases with about 119 million tCO2e.