nuclear plants

[NeilBlanchard]

Hi y'all,

Molten salt stored in heavily insulated underground tanks only loses ~1% of it heat per day. At 1100F starting temp, that leaves a pretty good range to generate high pressure steam.

The 10% transmission losses are for high voltage DC transmission lines -- which are excellent and the best we have at the moment. This is how we need to do all long distance transmission, and it would help for linking renewable energy sources with distant users.

Typical transmission losses however are a lot worse under heavy load conditions: 30% (or more).

Electricity generation efficiency is around 33% -- so 2/3 of the energy of the fuel used, is lost at the very beginning. And that doesn't even count the energy we invest in getting the carbon fuel in the first place (mining/drilling/transport). Exploration is yet more energy invested.

So, if you then add the inefficiencies for the user, the overall efficiency from the original fuel source to the "work" produced for the user -- it is somewhere under 10%, and it may be under 5%.

Now coal pollutes like nobody's business, and petroleum fire plants also spew a lot of nasty stuff -- and the effect of these is very costly. Nuclear has yet to have a solution for waste storage -- how much money have we invested to date?

All fuel based energy sources require to invest in exploration, fuel gathering, transportation to the plant that you have built -- and you to pay for fuel over the life of the generation system; plus they all involve maintenance. What will the cost of the fuel be in the future?!

Renewable energy systems require you to built the systems and to maintain them. There will be no increases in fuel cost; because there is no fuel involved.

[Duffman]

Originally Posted by NeilBlanchard

The 10% transmission losses are for high voltage DC transmission lines -- which are excellent and the best we have at the moment. This is how we need to do all long distance transmission, and it would help for linking renewable energy sources with distant users.
Typical transmission losses however are a lot worse under heavy load conditions: 30% (or more).

No you are wrong it is 10% for a typical grid and I challange you to produce concrete sources to the contrary. See Page 70 of the report, not the page 70 of the PDF.
http://www.saskpower.com/aboutus/cor...07FULLBOOK.pdf

Originally Posted by NeilBlanchard

Electricity generation efficiency is around 33% -- so 2/3 of the energy of the fuel used, is lost at the very beginning. And that doesn't even count the energy we invest in getting the carbon fuel in the first place (mining/drilling/transport). Exploration is yet more energy invested.

This is really irrelevant to the argument. Thermal efficiency is a red herring, output/carbon footprint is the measure that matters.

Originally Posted by NeilBlanchard

So, if you then add the inefficiencies for the user, the overall efficiency from the original fuel source to the "work" produced for the user -- it is somewhere under 10%, and it may be under 5%.
All fuel based energy sources require to invest in exploration, fuel gathering, transportation to the plant that you have built -- and you to pay for fuel over the life of the generation system; plus they all involve maintenance. What will the cost of the fuel be in the future?!
Renewable energy systems require you to built the systems and to maintain them. There will be no increases in fuel cost; because there is no fuel involved.

Neil it pretty clear to me that you are cherry picking your statistics. When a life cycle analysis is done the carbon footprint of resource extraction and the footprint of generation equipment is included. That is why nuclear comes out ahead of wind and PV solar, you have to count their construction costs too.

I took this from another person on another site but it is really good.

Not all megawatts are electric, though. You’re correct that I don’t think electricity generation capacity should go down in the future as we phase out fossil power. That is because I’d like to supplant fossil powered transportation and heating with cleanly generated electric power. If we go the route of Denmark, paying over 20c/kWh for the more fashionable forms of GHG-free energy, then we will severly impact the adaption of electric vehicles and heat exchangers.
As for noneconomic factors, talk of nuclear power’s big footprint baffles engineers. The energy released when you convert mass to energy (famously E=MC2 where C is the speed of light) is over a million times more than the energy released from chemically burning the same amount of resources. That again can release millions of times more energy than converting a unit of a resource’s motion into usefull power. This means is that a very small amount of both fuel and building materials is required for nuclear power and a massive amount of material is required for disperse alternatives like wind power. It would take about 10,000 giant windmills (1.5 MW rated producing about 600KW average) to replace the Bruce Generating Station. Typically these are spaced to about 4 per square km, so this is a 2,500 km2 farm. It would require about 7,500km (one Transcanada Highway) of access roads capable of sustaining 30+ ton truck loads to service the generator units, to which service people have to climb 20 stories in the air. Disregarding the roads, power lines, and even the bases for the towers, these windmills would use about 50 times more building material than Bruce. I think the powerline grids required by typical fauxe-green alternative power projects get forgotten. The regular defoliation they require is very expensive unless chemicals are used. Talk about footprint END OF QUOTE

Originally Posted by NeilBlanchard

Nuclear has yet to have a solution for waste storage -- how much money have we invested to date?

Again the costs of spent fuel storage and plant decommissioning are included in the operating cost per kWh generated and Nuclear is still cheaper than wind and solar.

When are you going to address the limitations of renewables other than to say diversify? What mix will you convert my province of Saskatchewan to, to ensure a reliable supply of electricity (hint the pdf above is a good place to start research).

[NeilBlanchard]

Hi,

You should check out Guy Dauncey's books and DVD -- he is located in Victoria. Germany is approaching 12% power from PV and they will probably get to well over 20% quite soon -- they have as much solar as in Washington state; which is just about the worst anywhere in this country.

Denmark is doing very well in wind power.

What is wrong with diversifying? If we can get 33% of our power from wind in South Dakota alone (or 66% if we double our efficiency), and if we can get 100% from solar in 10% of Nevada (200% if we double out efficiency)

and 18% from tidal, and an equal amount from wave power -- add in geothermal, biomass, and if we can cut our losses to transmission... It quickly becomes obvious that renewable energies can easily meet our needs, and then some.

Guy Dauncey estimates that we could collect up to 100X or 300X as power as we need:

Does it add up?

2004 global energy use: 120 TWh/year
Global sustainable energy need : 120 TWh/yr

A: Tidal 21 TWh + Biomass 75 TWh + Geothermal 137 TWh * + City Solar 31 TWh = 264 TWh = 2 x need

B: Wind: 628 TWh(Archer, 2005) = 5 x need

C: Solar deserts (120 TWh per 340,000 sq m) = 100 x need

D: Deep Hot Rocks Geothermal: 10 to 200 x need

Total = 100 to 300 x more power than needed

[Duffman]

Dauncey's numbers are big time out of whack, according to wikipedia the U.S. alone uses 29,000 TWh per year.

http://en.wikipedia.org/wiki/United_states#Energy

Neil, I have never dismissed the energy POTENTIAL of your renewable sources, yet you still evade my question.

[NeilBlanchard]

Hi,

I dunno -- I think the Wikipedia is also way off. I'm seeing numbers for worldwide electricity of 17,408 TWh/year (~25% of that is the USA?).

The energy alternatives | The power and the glory | The Economist

There is a graphic ~2/3 the way down.

But, in the text it says the world's population uses 15 terawatts of power -- but it doesn't say the length of time...

I've emailed Guy Dauncey for clarification -- it may be that is should be 120TWh/day?

[Edit: I found another Wikipedia page that pertains directly:

http://en.wikipedia.org/wiki/World_e...nd_consumption

[NeilBlanchard]

Hi,

I dunno -- I think the Wikipedia is also way off. I'm seeing numbers for worldwide electricity of 17,408 TWh/year (~25% of that is the USA?).

The energy alternatives | The power and the glory | The Economist

There is a graphic ~2/3 the way down.

But, in the text it says the world's population uses 15 terawatts of power -- but it doesn't say the length of time...

I've emailed Guy Dauncey for clarification -- it may be that is should be 120TWh/day?

[NeilBlanchard]

Hello again,

Here's the page I found that states losses can be up to 30%:

The Physics of Everyday Stuff, by Sam Hokin

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.

[emphasis is mine]

In my searches, I came across this Wikipedia page on distributed generation:

http://en.wikipedia.org/wiki/Distributed_generation

One favored source is solar panels on the roofs of buildings. The production cost is $0.99 to 2.00/W (2007) plus installation and supporting equipment unless the installation is DIY bringing the cost to $6.50 to 7.50 (2007).[1] This is comparable to coal power plant costs of $0.582 to 0.906/W (1979),[2][3] adjusting for inflation. Nuclear power is higher at $2.2 to $6.00/W (2007).[4] Most solar cells also have waste disposal issues, since solar cells often contain heavy-metal electronic wastes, (CdTe and CIGS), and need to be recycled. The plus side is that unlike coal and nuclear, there are no fuel costs, pollution, mining safety or operating safety issues. Solar also has a low duty cycle, producing peak power at local noon each day. Average duty cycle is typically 20%.

Another favored source is small wind turbines. These have low maintenance, and low pollution. Construction costs are higher ($0.80/W, 2007) per watt than large power plants, except in very windy areas. Wind towers and generators have substantial insurable liabilities caused by high winds, but good operating safety. Wind also tends to be complementary to solar; on days there is no sun there tends to be wind and vice versa. Many distributed generation sites combine wind power and solar power such as Slippery Rock University, which can be monitored online.

[Duffman]

I don’t think the numbers are off by much. Energy and Electricity values will be different. 17,408TWh/year would make sense for electricity if total energy was 29,000. I don’t think it really matters if the numbers are out by a factor of 2x, its when you approach 10x that it is significant.

Canada generated 570TWh in 2003 for 30 million people.
http://en.wikipedia.org/wiki/Electri...ctor_in_Canada

According to my utility document provided above we generated 20.5 TWh for only 1 million people. That report is an annual financial report for the corporation, its numbers have to be accurate because it is fraud to report otherwise.

I am sure line losses can approach 30% if you push enough power down a line. Average line losses for my provincial utility were 10% and again it is in the financial report so it is an accurate number. I did some more poking around on the internet and found this:
http://www.suezenergyresources.com/O...sses091905.pdf

Again all are 10% or well under.

I am not sure where you are going with your last article on costs. $/W of capacity doesn’t mean much without considering duty cycles. Fuel costs for nuclear are negligible wrt the capital investment. My attachment is taken from:
The Economics of Nuclear Power

Links with solar are hard to find but this one has them included and they are terrible.
On Global Warming: Is nuclear power carbon-free?

Its easy for some Phd author to take Wh/year totals from strong generating sites and say we only need so many units to power our nation or planet. Its purely theoretical! It entirely ignores the fact that the strong sites are clustered geographically, duty cycles are 20-30% but additionally can be strong or weak based on time of day or month of the year, but change day to day but overall is not predicatable in the long term. This is a serious engineering problem/challenge, not a 7th grade math question.

Again, my question was what is a suitable energy strategy for the province of Saskatchewan?

[dcb]

I do need to make one thing perfectly clear, this is a common misconception, but breeder reactors are NOT perpetual motion machines. They take Uranium and a few other materials as input and take the excess neutrons bouncing around during the fission process to make more fissionable material. It's not like you throw a couple banana peels in (though that would be cool), more like uranium 238 or thorium 232, it is not "renewable" by any sense of the term.


A lot of people get confused by the "it makes more fuel than it uses" statement in regards to breeder reactors, but in reality it is doing a bit of alchemy on an existing material.

[NeilBlanchard]

Hi,

I got a correction from Guy Dauncey -- all his numbers were missing three zeros: 120,000 TWh/year total, and the wind power number should be 210,000 TWh/year. He thanked me for catching it -- so the credit goes to you!

The bottom line is the same: there is a huge excess of renewable power sources available, and we just need to start to use them more; eventually we should use them for 100% of our needs.

I would think that wind would be a good possibility for Saskatchewan, similar to the upper midwest of the USA and to Denmark.