Nuclear Energy

Nuclear energy is energy released from the nucleus of an atom such as that of uranium-235. Nuclear energy is released by any of the following nuclear reactions :

• Fusion , the fusing together of atomic particles.
• Fission , the breaking of the binding forces of an atom's nucleus.
• Decay , a slower fission process.

The radioactive decay of the fissile material is accelerated in a controlled manner to create heat. This heat may be converted to kinetic energy by means of a steam turbine which is used to drive a generator for electricity production. About 7% of the World's energy needs are met by nuclear energy which includes 17% of all electricity. Construction of nuclear power plants declined after some incidents in the past. However, lately, there has been renewed interest from national governments, the public, and some notable environmentalists in nuclear energy due to the belief that it might be able to lower the environmental impact of energy use, particularly greenhouse gas emissions.

The use of nuclear power is controversial because of the problem of storing radioactive waste for indefinite periods, the potential for possibly severe radioactive contamination by accident or sabotage, and the possibility of its use in proliferation of nuclear weapons.

Hydrogen

Hydrogen is considered as an alternative fuel with great potential, and also as a power source of fuel cells . In spite of its ubiquity in nature, hydrogen is difficult to produce in large quantities. A lot of research is going on to discover new methods for hydrogen production; once succesful, hydrogen may become a viable alternative to greenhouse-gas -producing fossil fuels. Some of the methods being considered for production of hydrogen are:

• the electrolysis of water: simple but costly
• steam reforming natural gas: suitable for large-scale production.
• use of green algae
• conversion of biomass derivatives (example: glucose or sorbitol) at low temperatures using a catalyst .
• "steaming" of carbon: hydrocarbons are broken down by heat to release hydrogen.

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