能源.biofuel + nuclear power 優劣.

Nuclear power uses nuclear fission of uranium 235 to generate heat--> drives steam turbine generator to produce electricity.

Pros.
1) Only uses a small amount of nuclear fuel: 1kg of uranium produces energy = 70,000kg of oil and gas

2) Because uses less fuel: mining, transportation, operating costs are very low, hence quite cheap to operate e.g. 78% of electricity in France now nuclear. So economical that she sells lots of electricity to neighbouring states.

3) No carbon emission.

4) With new technology to recover unused nuclear fuel in spent fuel rods, there is enough uranium for 3,000 years (oil will run out in 40 years).

5) Some countries don't have oil and gas or coal (e.g. France, Japan). Nuclear is the most feasible alternative (otherwise international relationships/ oil prices will directly affect national energy supply)

Cons:
1) Produces radioactive nuclear waste which remain dangerous for about 20,000 years. No easy way to dispose of them yet.

2) Possibility of meltdown (like Chernobyl and Fukushima) if cooling system fails or reactor malfunction: DISASTER.

3) High start up cost and high cost in decommissioning it.

4) Strategic consideration: possible site for enemy or terrorist attack?

BIOFUEL can mean 2 things: making car fuel (biodiesel 生化柴油) from soybeans and corn, OR taking agricultural wastes (農業廢料), burn it to generate electricity (called biomass). I assume you're asking about the first one.

Pros
1) Renewable.

2) Overall lower carbon emission: when plants are grown they absorb CO2 so it balances with the emission during burning.

3) New biodiesel works just like ordinary diesel

Cons
1) Takes up food crops to produce fuel-->raise international food prices

2) Supply for soybeans and corn are shifted to less developed countries like Indonesia and Brazil: deforestation to grow them. Question: is this REALLY carbon neutral then? (moral consideration)

3) Current technology limits: biodiesel still more expensive.