- Nuclear energy.
- Hydro energy
- Solar Energy.
When Nuclear energy was first proposed, it seems like it is the answer to all the power but as you know now those who are using them have to find ways of disposing all the radio active waste generated. True the generators generate immense energy but the waste is very toxic to the environment.
Hydro energy is great for countries that are blessed with hills and waterfall. However, the process of building the dam and the reservoir for this requires that we clear out vast forest and eliminate natural habitats of animals there.
The other problem has to do with the sludge that will accumulate over the years when the hydro electric plant operates which if not handled properly will cause the plant to be unusable.
Overall though this is still one which causes the least damage but only if the construction and maintenance is done correctly (like planting back some of the plants damaged in the construction process).
This may be a good option except that the burning of coal isn't very efficient and generates a lot of carbon into the atmosphere which will contribute to the global warming effect.
Like oil, it will deplete one day, also the burning process is not very efficient
Wind is a great source energy for countries with vast open space like those with deserts. However, this is not an option for a lot of countries.
At first look, BioDiesel will be an answer to all our problems - renewable energy. However, look at the cost.
- Huge areas are cleared to plant the crops used for biodiesel. Crops like Palm (for palm oil), corn etc.
- Crops diverted to making biodiesel will not be available for food - thus contributing to the current food crisis.
- The amount of energy needed to convert these crops to usable biodiesel outstrips the energy it produces.
This is another promising technology, we have a lot of sun and also the sand.
However, I read in the paper a few months back, the plants in China making the solar panels have generated so much toxic waste that it is starting to affect the health of the people living near these plants.
Also the manufacturing, large recycling pools need to recycle the waste water also means a lot of vegetation has to be cleared - again contributing to global warming.
We have a lot of promising technology but for now all of them are contributing to global warming and is not helping us save the environment.