Water was an early energy source in the use of paddle wheels to run the mills and provided the transportation means for commerce. To improve those river routes they were dammed to control flooding and in some cases to produce hydroelectric energy too. Those early water mills were eventually replaced with coal as the industrial complex expanded. The discovery of electricity has completely revolutionized the industrial world and allowed mankind to spread out beyond the coast lines and water ways. However, we had also managed to dam almost every major river with hydroelectric generation for the ever increasing population. This has changed the ecosystems in many parts of the world and some cases were very destructive to biodiversity.
We live in a water world. Three quarters of the earth’s surface is water. Water is the essence of life. When I questioned my science guys on the internet about water as a future energy source, this is one of the answers I got back. “the energy content of deuterium (H2) in seawater would be enough for 29.5 billion years of energy supply.” To put that answer into perspective I thought I would also include the calculations as much as I hate to bore you with numbers: “The complete conversion of deuterium nuclear fuel releases an energy content of 250 x 10^15 joules per metric ton of deuterium. The quantity of deuterium in the world’s oceans is estimated at 4.6 x 10^13 metric tons. Deuterium present in seawater will yield around 5 x 10^11 TW-years of energy. In the year 2013 the entire planet consumed around 17 TW-years of energy”. Hence the 29.5 billion years of energy supply.
To fully appreciate that estimate of energy, you have to remember that the earth will only be around for another 5 billion years. To give all 10 billion people expected to be living on the planet in 2050 the level of energy prosperity we in the developed world are used to, we won’t have a problem with finding that energy. The real problem that has to be overcome is how to deliver the energy to all those people. All that energy would have to be based on clean nuclear fusion technology which is still in the development labs around the world. In the meantime, we still have semi-clean fossil (with NG) and nuclear fission technology to work with. But we do need to expand the use of cleaner fossil and advanced fission reactors to fulfill the increasing demand for more energy based on continued increases in population and industrialization.
While water could be the essence of energy for the future, it is also essential for food production and drinking water, which must rely on that measly 1% usable fresh water out of all the water we can see in our oceans. Dams have always been used to manage water flow in our rivers and water diversions have been used to provide water where it is needed, not just where it naturally flows. The Colorado River is a good example of a river that has been completely used up. It has been damned at multiple locations and diverted to many different areas from New Mexico to California. There is no water left after Mexico takes its share before it was suppose to flow out into the Gulf of California. Where is the additional fresh drinkable water going to come from when other streams, rivers, lakes and ground water are also depleted? Is that possible and if so, what can we be doing to resolve the shortages? Desalination is the answer and that will require a lot of heat energy. I guess that makes energy the essence of life on earth.