It is a fundemental understanding, in our physics, that energy cannot be created or destroyed, just converted from one form into another. Example: the potential energy of water behind a dam is converted to kenetic energy through pipes and to mechanical energy in a turbine and finally to electrical energy when the turbine drives a generator.
A second understanding, in our physics, is of entropy, which is generally described as ‘increasing disorder’. A way to describe this is to set a brick house up in the wilderness, coming back in a thousand years you’d quite reasonably expect to find a pile of bricks; this is known as ‘positive entropy’. On the other hand, if we set out a pile of bricks we would not expect to find a brick house in a thousand years. If a pile of bricks turned into a brick house it would be ‘negative entropy’ or increasing order.
In energy conversion, these two understandings combine to describe high and low level energy. High level energy, (like electricity) is like a brick house, hard to aquire. High level energy easily and efficently converts into low level energy (like heat) which is like a pile of bricks. We can make close to 100% heat with 100% electricity. It is hard to turn heat into electricity; we throw away up to 99% of our heat energy to get 1% electricity. The very best thermodynamic cycles I know, still throw away 40% of the heat energy to make electricity.
Electricity is the premium energy in our civilization. We convert many other forms of energy to electricity. At Eagle-Research we experiment with converting natural, environmental energies to electricity. We look for forms of energy that will not cause our fragile environment to degrade. Examples are all over this website, like electromagnetic energy, eco-fuels and gravity.
Burning oil and coal are extremely bad for the environment as we know it. Nuclear energy not only costs more energy to produce than you get out of it, but you are left with a deadly residue that stays deadly for 100 thousand years or more (that’s what the half life propaganda really means).
So called ‘clean’ hydro energy is nice except for three things:
1 We flood our best agricultural land (river bottom).
2 There are not that many places that it can be used.
3 Most of the dams have only decades life span, because the reservoirs fill up with silt.