The energy we use comes from different sources: non-renewable energy and renewable energy.
Non-renewable energy includes oil, coal, gas, shale gas (= « gaz de schiste ») and nuclear energy.
The world still largely depends on oil. Production and prices vary according to the law of supply and demand (= « l’offre et la demande »). There were two major crises: in 1973 and 1979, when the price of crude oil (= « pétrole brut ») rose sharply. Crude oil is a fossil fuel (= « énergie fossile »).
In the US the production of shale gas is increasing rapidly. However hydraulic fracturing, or fracking, the technique used to recover gas and oil from shale rock is considered to be controversial by many people. Fossil fuels in general are said to be bad for the environment.
Some countries are trying to phase out (= « éliminer progressivement ») fossil fuel vehicles. Automakers are developing zero-emission vehicles (ZEVs).
Nowadays because of climate change, other sources of energy are being developed.
Renewable energy can replace itself quickly and so can be used over and over again. It includes: solar energy, wind power (= « énergie éolienne »), biomass and geothermal energy.