Our two energy sources are Solar and Nuclear. Solar is a renwable resource that harnessess the sun's energy, and Nuclear is a renewable resource that harnesses the energy of the nucleus of an atom
As stated, Nuclear enery is nonrenewable, and harnesses the energy that comes from the nucleus of an atom- namely, uranium. Urainium is incredibly dense, and as such a nuclear plant could run for a year an and a half on just one load of fuel, without releasing CO2. Basically, Nuclear is one of the only energy sources that could match fossil fuels at scale. Nuclear plants are also one of the safest, due to all the precaution. Of three nuclear incidents, only one was fatal. On the flip side, even though producing the energy is cheap, containing it requires expensive facilities. In addition, nuclear is viewed as a danger, so plants face a lot of public dissent.
Solar energy is energy harnessed from the sun. The fuel is free, and the panels themselves are easy to make and use. The main disadvantage comes from the fact that the sun isn't always shining, so the main expense of solar energy is storing it. In addition, large-scale solar fields take up a lot of space, which is often needed for other things or inhibited by wildlife. In short, solar is emission free, but can cause enviornmental impact on a large scale, and cheap, until the cost of countermeasures for no sun add up.