Sustainable energy and sustainable energy sources

By definition sustainable energy is the provision of energy such that it meets the needs of the present without compromising the ability of future generations to meet their needs. That means that sustainable energy is energy which is replenishable within a human lifetime and causes no long-term damage to the environment. From this definition it is clear that all renewable energy sources are sustainable because base energy providers for renewable energy sources are very stable and human activity can not influence those energy providers in some larger scale. For example, nuclear fusion on Sun will continue for a very long time (biofuels, solar power, wind power, wave power …), the Moon will also circle around the Earth for next couple of billions of years (tidal power), and Earth will not cool down very soon (geothermal power). Nuclear energy can be also considered as sustainable energy source because after nuclear fission era we will probably enter nuclear fusion era. Nuclear fusion is much cleaner energy source than fission and amount of fuel for fusion is practically unlimited – hydrogen and hydrogen isotopes.

Sustainable energy - sunflower (biofuels).

Fossil fuels (oil, coal and natural gas) are not sustainable energy sources because they are limited in quantity and they cause long-term damage to the environment. Currently we do not know how to produce new oil, coal or natural gas without using more energy than we can get from that. Because of that we will use all fossil fuels created naturally and future generations will have to come up with some new energy source to meet their energy needs. Limited quantity of fossil fuels is in some way good for future generations because maybe we will run out of oil before we ecologically mess up entire World.

Because of fossil fuels, some energy sources that are currently being considered as a sustainable energy sources may become out of reach for us. For example, if we put to many dangerous gasses into atmosphere solar energy will become useless because of simple fact – to small amount of that energy will reach the Earth. That can then have big impact on other energy sources, for example if the amount of sunlight is not enough to sustain photosynthesis all plant will vanish and with that we will lose biofuels and biomass as energy sources. But, if that happens we will have much bigger problems than producing energy…