Engineering News

Old info but: approx 15 years ago I watched a documentary about nuclear power plants. At that time in the U.S., nuclear power plants had 15 year life expectancy but the total energy to build the power plant was approx 20% of the total energy the power plant would produce during its life time of operation. It is probably better today but this still seems like a very lossy system. I do not hear about these facts now days. The people in charge probably want to hide these facts.

As far as England is concerned, I figure they have a tremendous source of green energy surrounding them. Just harness some of the ocean currents around the British Islands. This would require a large investment but the real return on this investment would surely be as great and important as the commuter tunnel under the English Channel to France.

Ocean currents are free and continous and do not have to be replaced.

http://nuclearinfo.net/Nuclearpower/SSRebuttalResp

The above link addresses (rebuts) studies postulating high energy costs for construction and fuel for nuclear power plants. I know it's a thick read, but there is little doubt that the 20% figure is erroneous.

Fuel costs in the US are customarily less that 1 cent per kwhr and include cost of mining, chemical conversion, enrichment, and fuel fabrication, including associated energy costs. Disposal is addressed by a 0.1 cent per kwhr charge.

New nuclear plant will be designed for a 60 year life, and most current US plants, orginally designed nominally for 40 years, will be going in for life extension permits to allow 60 years of operation. Since production costs for well run nuclear plants runs at less than 2 cents per kwhr, it's a bargain. The US fleet currently runs with an overall capacity factor of about 90%. They are well run.

If these plants were not built nuclear, they would likely have been coal fired. If so they would be producing an amount of CO2 exceeding that currently produced by all of the automobiles in the US.

There are major problems with using tidal energy round the UK:

1. You are dealing with a very corrosive fluid = seawater.
2. Any method of energy extraction from tidal streams would use "old electro-mechanical" technology, which is not very efficient.
   
3. Any structure to extract tidal energy raises the sea level behind it.
4. Southeast England is still sinking, and in a few short years, the expensive Thames Barrier may well be overtopped by a "Tidal or storm surge".
5. Northern Scotland is still rising, so after time, those energy trapping structures would be left "high and dry".
   
6. If England was "made safe", by building higher defensive structures, then the problem of the "tidal surge" would just be transferred elsewhere = The Netherlands.
7. Interference with the "Gulf Stream" and consequent major weather changes for UK and Europe.
   
8. Ocean currents are as you say "free" but in long-term analysis, fish spawning, shipping, and many other factors need to be considered.

Note that extraction of energy, from tidal streams, actually slows the Planet Earth rotation.

Sure it does not seem to slow it much, but if hundreds of thousands of large tidal energy installations were built, the slowdown would become appreciable, causing the Moon to spiral in closer, until the Roche limit was eventually reached, and the Moon torn apart.

Meanwhile, because of the greater gravitational effect of the Moon becoming closer, tides around the Earth could rise to well over 1000 feet differential between high and low tides, along with major damages and death for much of the Earth's population.

It is true that the tides slow down Earth's rotational speed but the tides generated by the Moon actually increase the radius of the Moon's orbit.

I think the length of an Earth day approx increases by 0.25 seconds in 100 years. This means that Earth's kinetic energy, due to rotational speed, is decreasing but many factors cause this. One factor is the coupling of the Earth to the Moon by way of Lunar tides. Due to conservation of energy, this kinetic energy loss of the Earth is transfered to the Moon which increases the Moon's orbital radius around the Earth in the form of increasing the potential energy of the Moon within Earth's gravitational force.

Some day a long long time in the future, the Earth will be spinning much slower and the Moon will be far far away but not to worry because man will not be on Earth by that time. Man will either exterminate himself (nuclear war or equivalent, or man made global warming) or be wiped out by natural causes such as nature-driven environmental changes, astroid collision with Earth, ect.

MARK MY WORDS, YOU PERSONALLY DO NOT NEED TO WORY!!!!!!!

This increase in length of a day will take around 200million years for 10% of change.

So wait and search for real trouble.

Sparky for G-d!