文档介绍：Integrated Science Renewable and Nonrenewable energy sources
Introduction of sources of energy
Non-Renewable
Fossil Fuels
Nuclear
Renewable
Wind
Solar
Tidal
Hydropower
5. Geothermal
Non-Renewable energy sources: Fuels
What are fossil fuels ?
A fuel is any substance used as a source of energy, including heating, transport, electricity generation and other uses.
Most of the world’s energy is provided by the burning of fossil fuels (化石燃料).
Coal, Oil and Gas are called "fossil fuels”because they are bustible substances formed originally from dead plants and animals.
The major fossil fuels are
coal (煤),
petroleum (石油) and
natural gas (天然氣).
Fossils fuels are non-renewable (非再生能源) energy sources.
This is because fossil fuels take millions of years to form. Once they are used up they can never be replaced.
World Fuel Resources
Petroleum or Oil
Natural Gas
Coal
Power reserves
130 billion tonnes
158 billion cubic metres
950 billion tonnes
Total used in 1990
billion tonnes
cubic metres
billion tonnes
From the above table, the present world's estimated oil reserves may be used up in the next 50 to 60 years.
Coal
Coal is the plants ,that grew in swampy areas about 300 millions ago, died to form layers of decaying material.
Heat, pressure and the action of bacteria changed the decaying plants into coal.
How it works:
Coal is crushed to a fine dust and burnt.