Introduction into energy sources

Life on the Earth began and survived millions of years thanks to the favorable climate conditions. Climate can be viewed as the renewable energy source that has energetic component in Sun energy and material components in oceans as water reservoirs. Energy of the Sun supports circling of water on the Earth, therefore making life on Earth possible. Where there’s no water, there’s no quality life, like for instance in deserts. Earth’s climate changes have reached the level of climate crisis. The solution of how to get out of this crisis is very simple-return to less harmful energy sources. However, lobbies that support continued use of fossil fuels and nuclear energy are too strong on energy market and at this particular moment there’s no signs of slowing down the use of "dirty" energy sources. Such approach could very easy endanger the future climate, making the life of climatic sensible plants and animals almost impossible, since all species live in natural balance that would affect all earth’s bio-system. To avoid this grim prediction of Earth's future life, some countries started stimulating saving energy programs and transition to "clean" energy sources. Globally, there’s no major progress because amount of energy gained from these clean energy sources is negligible to energy that is gained from fossil fuels and nuclear power plants.

World energy consumption between year 1900 and 2000. Energy consumption was enlarged ten times.

This picture shows the world energy consumption from year 1900 to year 1997. We can see that energy consumption in the first half of the 20th century was doubled, and after this period, in the second half of the 20th century world came to a considerably higher energy consumption. Consumption of energy is ten times bigger than it was in beginning of the 20th century. Major energy sources of 20th century were nonrenewable energy sources. These are:

• coal
• oil
• natural gas
• nuclear energy

Coal, oil and natural gas are also called fossil fuels. Two main non-renewable energy sources' problems are limited quantity and environment pollution. Combustion of fossil fuels liberates large quantities of CO₂ which is a greenhouse gas. This is probably the primary reason of global temperature increase. Nuclear power plants aren't dangerous for the atmosphere, but substances created as the result of nuclear reaction remain radioactive for years, and should be stored in special chambers. Renewable energy sources aren't suffered by similar problems. Most significant renewable energy sources are:

• wind energy
• Sun energy
• bioenergy
• water energy

Renewable energy sources do not pollute environment in the same measure as do non-renewable, but they're also not completely clean. This primarily affects to the energy gained from biomass which has the same effect as fossil fuels, and that is liberating CO₂ when combusting. Biggest problems of renewable energy sources (water energy excluded) are price and little amount of gained energy. Renewable energy sources have huge potential, but at this moment our current technological development isn't allowing us to rely strictly upon them.

Greenhouse Effect

This picture shows the "Greenhouse Effect". Part of the reflected sun emanation absorbs itself in greenhouse gases (CO₂, N₂O, CH₄, HFC, PFC, SF₆), and that effect insures constant earth's temperature. If there wouldn't be greenhouse effect, Earth's temperature would be 30°C lower than it is now. Since the concentration of the carbon dioxide has grown bigger during the last century, greenhouse effect is more and more expressed. This has consequence in the global increase of the average Earth's temperature. Consequences of global warming are ice hood melting, sea level lifting, agriculture influence and similar other things. Major sources of CO₂ are wood and biomass combustion, deforestation and fossil fuels combustion. In 1997 Kyoto protocol was signed up, to decrease emission of C0₂ in to the atmosphere. Countries that signed this protocol obliged themselves to decrease the emission of CO₂ in to the atmosphere. Every country has its own determined percentage in decreasing emission of CO₂, and it all relates to decreasing it, until year 2012 in relation to year 1990. The average planned decrease is 5.2% until the year 2012. Major issues concerning the Kyoto protocol are the fact that USA hasn't ratified it, and large expenditures of replacing momentarily "dirty" energy sources with "clean" energy sources. Term "dirty" energy sources applies to biomass and fossil fuels, while "clean" energy sources are nuclear power plants and renewable sources without a biomass.

Actual relation of energy sources

Fossil fuels are the main energy source used for supplying the actual mankind needs and are giving 85-90% of world's energy. Oil is in first place with 35%, with coal and natural gas being equally represented. Nearly 8% of all energy is gained from nuclear power plants, and just 3.3% comes from renewable energy sources. Vast majority of energy gained from renewable sources relates to the water energy. Other renewable sources are momentarily energetically negligible. Since in the future we'll be forced to satisfy our energy needs from renewable sources, we have to think of the way to transform renewable sources to an useable energy. The main obstacles are expensive and long-lasting researches, with most transformations relating just to the production of electrical energy. Factor that contributes to higher researching expenditures is also variety of renewable energy sources.