The Weebly 'document' upload seems to be broken; hence the odd last post. I do not have time to find a workaround.
Eventually much present fossil carbon energy will be superseded by "replacement energy"
A very serious question is whether or not replacement energy is viable in the sense that it delivers more energy to society than the energy needed to make the devices used.
Here is a short article on how to make simple rough estimates of what is called "EROI"
The Scribd iPad viewer does not appear to work. You can download the PDF here.