Come on ! This is basic planning. Losses are always there and they are not negligible even in HVDC transmission lines. Long HVDC routes are used only when the power source is fixed and can't be put near a population center i.e hydroelectric power
All right, we've had enough of this usage of subjective adjectives, and I am the one who started it by using adjectives like '
negligible'. Now, let's get down to some math:
High-Voltage Transmission Lines
So we now finally come to the topic of this page: the transport of large amounts of electrical power over long distances. This is done with high-voltage transmission lines, and the question is: why high voltage? It certainly has a negative safety aspect, since a low voltage line wouldn't be harmful (you can put your hands on a 12 V car battery, for example, you won't even feel it; but make sure you don't put metal across the terminals, you'll get a huge current and a nasty spark!). Electric energy is transported across the countryside with high-voltage lines because the line losses are much smaller than with low-voltage lines.
All wires currently used have some resistance (the development of high-temperature superconductors will probably change this some day). Let's call the total resistance of the transmission line leading from a power station to your local substation R. Let's also say the local community demands a power P=IV from that substation. This means the current drawn by the substation is I=P/V and the higher the transmission line voltage, the smaller the current. The line loss is given by Ploss=I²R, or, substituting for I,
Ploss = P²R/V²
Since P is fixed by community demand, and R is as small as you can make it (using big fat copper cable, for example), line loss decreases strongly with increasing voltage. The reason is simply that you want the smallest amount of current that you can use to deliver the power P. Another important note: the loss fraction
Ploss/P = PR/V²
increases with increasing load P: power transmission is less efficient at times of higher demand. Again, this is because power is proportional to current but line loss is proportional to current squared. Line loss can be quite large over long distances, up to 30% or so. By the way, line loss power goes into heating the transmission line cable which, per meter length, isn't very much heat.
Source: http://www.bsharp.org/physics/transmission
Note the text and equation highlighted in
red. If power is constant, transmission line resistance is constant, then the loss fraction goes down dramatically with increase in voltage (and decrease in current). This decrease is not linear, but
exponential. Therefore, the following statement is proven (yes, loss fraction can be made into a 'negligible' value):
Transfer power by increasing Voltage and reducing Current and you can cut down losses to a negligible amount.
No point in wasting fresh potable water when sea water is freely available
I am not going to assume anything and this could be purely coincidential, however, I do see a connection between what you are saying about sea-water and this news article:
Japan authorities inject water at nuclear plant, relieving pressure.
I am no expert, but as far as I know, saline water is not directly used in a Nuclear Reactor and has to be processed (correct me if I am wrong). Moreover, usage of saline water for instances like the one above happens only in disaster situations. Now, whether saline water can be used or not is not the point. The point is that even if we need to have a good supply of water somewhere inland, we can draw them from rivers, build reservoirs and dig canals. If Indian Railways could lay railway tracks all over the country, if VSNL along with other major telecom companies, Sprint being one of them, could lay optical-fibre cables from India to Canada then how difficult is it to build a canal to supply water to these N-Plants?
Kindly note that there are plenty of examples of nuclear reactors that are away from the sea. Also note that sea is not the only source of water. Finally, inland water is not necessarily fresh and potable and you can look up sub-surface pollution and arsenic poisoning to verify that, but I won't dwell on it much because then we will go off on a tangent. Some examples with a few maps:
List of nuclear reactors.
In North Carolina, 2 out of 3 N-plants are away from the sea and you can verify it
here. You can also see the
list of US N-Plants.
Reminder: This discussion started with me expressing reservations about not a single of the proposed sites being in the low seismic zone (white). I am doing this so that readers keep it in mind what I am trying to say (see below).
Whoever's bright decision was this map (refer to the stars)? Not a single of the proposed sites are in the white zones!
