Renewable Energy Vs. Nuclear Energy

Renewable energy is generally classified as any energy source that is self-replenishing, such as sunlight, geothermal heat, wind and moving water. Their utilization as power sources does not diminish their availability.
Nuclear power, however, relies on the mining of uranium and related radioactive elements. Though the utilization of uranium provides more power over a longer period of time than petroleum or coal fuel, its use does decrease its overall availability in the long run.
The debate over whether to use nuclear or renewable energy for long-term power supplies is based upon whether or not the sum of one's advantages and disadvantages outweighs the other's.

Advantages of Renewable Energy

One of the distinct advantages of renewable energy is simply the lack of the need to transport fuel to generators. Hydroelectric dams take advantage of existing streams; photovoltaic cells utilizes direct sunlight; wind generators take advantage of the atmospheric movement inherent in a rotating planetary body.
Renewable energy, especially solar and wind power, is also extremely scalable. Multiple generators can be installed across a wide geographic area. The recent development of floating wind turbines means that the geographic area does not necessarily have to be on solid ground.

Drawbacks of Renewable Energy

Many forms of renewable energy are difficult to match to demand. Environmental and climate conditions affect the feasibility of solar and wind power.
Some forms of renewable energy are also extremely costly, both in terms of construction and on the environment. Hydroelectric dams have displaced existing communities and affected wildlife, because of the flooding they cause. Dams also contribute greatly to carbon dioxide release for the same reasons.
Land use is also a concern with renewable energy, as solar and wind power utilize large swathes of real estate, causing a significant opportunity cost for land development.

Advantages of Nuclear Energy

Nuclear energy has the largest baseline energy output per unit of any available electrical energy source. Though the individual units of uranium it uses are costly, its ability to be used over a significantly long period of time makes it a more effective fuel source than petroleum. It has been mistaken for a renewable energy source thanks to its ubiquitous presence not only in the earth, but also in seawater.

Drawbacks of Nuclear Energy

There are many serious problems with nuclear energy, starting with the enormous cost of establishing a nuclear power plant. Costs for a new reactor can run as high as $15 billion, making it extremely cost-prohibitive for most communities, and even nations.
A more intrinsic problem, however, is the issue of what to do with nuclear waste. The highly radioactive byproducts of nuclear fission create a massive health and security hazard, and remain so for thousands of years. There is currently no easy way to handle nuclear waste.

Other Alternatives

Fusion energy, while sharing the cost problem of fission reactors, promises two major benefits in the use of nuclear energy. The first is the avoidance of the radioactivity problem inherent in fission energy, as fusion's radioactive byproducts are much shorter-lived.
The second advantage to fusion energy is its theoretically massive power output. The industrialized world's increasing demand for energy makes a single fusion plant arguably more tempting than an equivalent amount of renewable energy sources, because of the greater geographic coverage the latter would take up.