Nuclear Fusion vs Nuclear Fission

• Nuclear fission is used to generate electricity in nuclear power stations.
• The nuclear fission reaction splits large nuclei into new smaller ones. These new nuclei are usually radioactive.
• Because the products left over after nuclear fission are radioactive, they can't just be thrown away. This is radioactive waste.
• Radioactive waste is difficult and expensive to dispose of safely.
• Nuclear fuel is cheap but the overall cost of nuclear power is high.
• This is because it costs a lot of money to set up the power plant and make it safe.
• Even more money is spent on final decommissioning (shutting it down) and dealing with all the waste. 
• Nuclear fission reactors also carry the risk of radiation leaks from the plant.

...So People are trying to Generate Electricity using Nuclear Fusion

• Fusion doesn't leave behind a lot of radioactive waste, and there's plenty of hydrogen for fuel.
• The big problem is that fusion can only happen at really high temperatures - like 10 000 000 degrees celsius.

• The temperatures and pressures needed for fusion are too high to be able to do it in an ordinary container. There are a few experimental reactors around, but none of them are generating electricity yet.
• At the moment it takes more power to get up to the right temperature than the reactor can produce.