Nuclear power won't fix the energy problem

AI Thread Summary
The discussion critiques the notion that nuclear power can effectively address the energy crisis, arguing that it is often misrepresented as a viable alternative to oil. It emphasizes that electric vehicles currently lack practicality and infrastructure, making them inadequate substitutes for traditional transportation methods. The conversation highlights that while nuclear energy is cleaner than coal, it cannot resolve transportation issues without advancements in energy storage technology. Concerns about nuclear safety and the potential for terrorism are raised, but the argument suggests that nuclear energy is statistically safer than other industries. Ultimately, the consensus is that without significant improvements in energy storage, neither nuclear nor renewable sources can replace oil for transportation needs.
  • #101
DaleSpam said:
Sure we do. Plug-in hybrids already exist. Commuter transportation could be entirely serviced by electricity with existing battery technology.

Not even close. Some commuters who only need a small amount of energy for commuting could use electric from hybrids, but battery technology is far too limited for most commuters. That is precisely why, in his misguided attempt to improve the situation, McCain is calling for a 300 million dollar prize for an effective battery. Of course this makes no sense because the market would more than reward any company that could make an effective battery for electric cars. Or are you arguing that McCain is completely fabricating the need for such technology? What's more, anyone who only needs the little bit of energy stored in batteries should use public transportation, rather than running a hybrid.

And we have yet to consider the cradle to grave energy costs of hybrids and all of those dirty batteries, which have a short lifespan. Standard lead-acid batteries ars good for about 1000 charge cycles if we only discharge to about 60% of capacity with each cycle.
 
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  • #102
I recently did a project where we needed to store enough energy in batteries to produce about 7HP for 20 minutes. It took 8 large truck batteries.

Most cars can produce at least 100 HP.

The electric grid is already facing problems in both supply, and infrastructure.
 
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  • #103
North America's world-class electric system is facing several serious challenges. Major questions exist about its ability to continue providing citizens and businesses with relatively clean, reliable, and affordable energy services. The recent downturn in the economy masks areas of grid congestion in numerous locations across America. These bottlenecks could interfere with regional economic development. The "information economy" requires a reliable, secure, and affordable electric system to grow and prosper. Unless substantial amounts of capital are invested over the next several decades in new generation, transmission, and distribution facilities, service quality will degrade and costs will go up. These investments will involve new technologies that improve the existing electric system and possibly advanced technologies that could revolutionize the electric grid.
http://www.energetics.com/gridworks/grid.html

Climate change and rolling blackouts may be a package deal. More frequent and intense heat waves expected in California over the next 100 years could overburden the state’s electric utility grid, according to a study led by scientists in the U.S. Department of Energy’s Lawrence Berkeley National Laboratory.[continued]
http://www.physorg.com/news6593.html

And then there is the issue of water
California Looks to Desalination for Water Woes
by Amy Standen

Listen Now add to playlist

All Things Considered, August 25, 2007 · Desalination plants used to be found only in oil-rich countries like Saudi Arabia. Now, as water becomes an ever more precious resource in California, proposals for 18 desalination plants are being studied by local officials from San Diego to Marin County. The largest would be in the Bay Area. [continued]
http://www.npr.org/templates/story/story.php?storyId=13950883

So, what is sillier than piping water 1000 miles to keep the fountains at Disneyland flowing? Well, desalination, of course… Desalination uses even more energy than piping water from Northern to Southern California, 4,000 kWh/Acre-foot (3.24 Wh/liter). This is because desalination either uses reverse-osmosis filtration, essentially filtering ocean water by pumping water, at high pressure, through a membrane, or distillation, where water is evaporated and condensed. Both of these methods require a lot of energy for pumping and/or heating the water.[continued]
http://www.triplepundit.com/pages/askpablo-desalination-and-the--002579.php
 
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  • #104
Ivan Seeking said:
Some commuters who only need a small amount of energy for commuting could use electric from hybrids
I think you are missing the economic point here. These "some commuters", even if they represent only a small portion of the total market, will have a great impact on the marginal price elasticity of demand. The only way the economic problem is solved is through diversification, and it doesn't take a lot to make a large impact.

Ivan Seeking said:
the market would more than reward any company that could make an effective battery for electric cars.
That has only become true in the last few months. You, of all people, should know how economically unbeatable cheap oil has been for decades.
 
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  • #105
Ivan Seeking said:
Not even close. Some commuters who only need a small amount of energy for commuting could use electric from hybrids, but battery technology is far too limited for most commuters. ... What's more, anyone who only needs the little bit of energy stored in batteries should use public transportation, rather than running a hybrid.

And we have yet to consider the cradle to grave energy costs of hybrids and all of those dirty batteries, which have a short lifespan. Standard lead-acid batteries ars good for about 1000 charge cycles if we only discharge to about 60% of capacity with each cycle.

Ivan Seeking said:
I recently did a project where we needed to store enough energy in batteries to produce about 7HP for 20 minutes. It took 8 large truck batteries.

Most cars can produce at least 100 HP.

The electric grid is already facing problems in both supply, and infrastructure.
We've been through all this.
https://www.physicsforums.com/showpost.php?p=1584293&postcount=12
Electric hybrid plug in vehicles are indeed very close; half a dozen models will come out in the next two years. They will be using Li Ion batteries. They have the energy density and the lifecycle. Nobody is proposing to use old tech lead acid batteries for electric cars. Edison tried and failed to make that work early in the last century. Li Ion has 5 to 8x the energy density of lead acid.
http://en.wikipedia.org/wiki/Energy_density and that's only comparing ones you can buy off the shelf right now. Lithium is not a heavy metal and is not near the threat to the environment (as lead acid). The issue at the moment is cost, as batteries are at the margin of economic viability. The US electric grid has plenty of spare capacity at night (day load ~100GW > night load) to charge a substantial commuter fleet, in fact the electric utilities are very interested in selling that currently unloaded night capacity.

Article on A123 - supplier for the Chevy Volt
https://www.technologyreview.com/read_article.aspx?ch=specialsections&sc=batteries&id=20570
"Plug-In Hybrids: Tailpipes vs. Smokestacks"
http://www.technologyreview.com/read_article.aspx?ch=specialsections&sc=transportation&id=20213

Since utilities have built enough power plants to provide electricity when people are operating their air conditioners at full blast, they have excess generating capacity during off-peak hours. As a result, according to an upcoming report from the Pacific Northwestern National Laboratory (PNNL), a Department of Energy lab, there is enough excess generating capacity during the night and morning to allow more than 80 percent of today's vehicles to make the average daily commute solely using this electricity. If plug-in-hybrid or all-electric-car owners charge their vehicles at these times, the power needed for about 180 million cars could be provided simply by running these plants at full capacity.
 
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  • #106
DaleSpam said:
I think you are missing the economic point here. These "some commuters", even if they represent only a small portion of the total market, will have a great impact on the marginal price elasticity of demand. The only way the economic problem is solved is through diversification, and it doesn't take a lot to make a large impact.
Commuters are not a small portion, they are the majority share of transportation fuel use.

And given that half the cars on U.S. roads are driven 25 miles a day or less, a plug-in with even a 20-mile-range battery could reduce petroleum fuel consumption by about 60%
www.calcars.org/epri-driving-solution-1012885_PHEV.pdf
Im skeptical of that figure, 60% must refer to transportation fuel use only (65% of the total). Even so, 30-40% relief from oil would change the energy situation dramatically in net importing countries.
 
  • #107
mheslep said:
Commuters are not a small portion, they are the majority share of transportation fuel use.
I thought so, but it wasn't worth arguing the point, since even a small portion will have a relatively large impact on the economics of petroleum.
 
  • #108
So, what is sillier than piping water 1000 miles to keep the fountains at Disneyland flowing? Well, desalination, of course… Desalination uses even more energy than piping water from Northern to Southern California, 4,000 kWh/Acre-foot (3.24 Wh/liter). This is because desalination either uses reverse-osmosis filtration, essentially filtering ocean water by pumping water, at high pressure, through a membrane, or distillation, where water is evaporated and condensed. Both of these methods require a lot of energy for pumping and/or heating the water.[continued]

http://www.triplepundit.com/pages/as...he--002579.php


A little later in the article:
But innovative solutions are under development. A new concept desalination plant utilizes ocean breezes and cold ocean water. It does this by piping cold ocean water through pipes. The water is then sprayed on a screen where some of it is picked up by the breeze in the form of humidity. The humid air then passes over the cooled pipes, where the water condenses and is collected, salt free.
I'm not sure about that, since the fog rolling in over San Francisco and Golden Gate bridge contains - sea salt! And why use cold water - perhaps it's less saline.

If evaporation (and condensation) were used with solar thermal energy as the source, then it would make sense. And perhaps using process heat from nuclear plants would make sense too.

I heard recently that some California tomato farmers have simply walked away from their fields, leaving the plants to whither, since it costs too much to produce the tomatoes (water and fuel costs).

There have also been power cycles based on thermal differentials between ocean surface and deep (cold water).

Nuclear can play a role, but it is not a solution by itself. Part of the solution is conservation and efficiency. Nuclear suffers from the inherent limitations of the efficiency of the Rankine cycle (~34-37% efficiency). Higher temperatures can be used in some advanced designs, but there are materials degradation issues that challenge the economics, reliability and safety.
 
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  • #109
DaleSpam said:
I think you are missing the economic point here. These "some commuters", even if they represent only a small portion of the total market, will have a great impact on the marginal price elasticity of demand. The only way the economic problem is solved is through diversification, and it doesn't take a lot to make a large impact.

In a static market, it appears that you would be correct, but you are not considering the increasing demand beyond what we have today. And that was part of my point in posting the references to the need for clean water. The grid is already in trouble, and we already have huge additional demands coming online.

That has only become true in the last few months.

This has been true for as as long as I can remember. Do you remember the gas shortages of the 70s?
 
  • #110
mheslep said:
We've been through all this.
https://www.physicsforums.com/showpost.php?p=1584293&postcount=12
Electric hybrid plug in vehicles are indeed very close; half a dozen models will come out in the next two years. They will be using Li Ion batteries. They have the energy density and the lifecycle. Nobody is proposing to use old tech lead acid batteries for electric cars. Edison tried and failed to make that work early in the last century. Li Ion has 5 to 8x the energy density of lead acid.

We have been through that. The Tesla has probably $50,000 worth of batteries.
 
  • #111
Ivan Seeking said:
This has been true for as as long as I can remember. Do you remember the gas shortages of the 70s?
I'm going to call "BS" here. Unless you were in a coma between the gas shortages of the 70's and now, then you are well aware that petroleum has been unbeatably cheap for most of that time.

I know you are not intentionally being dishonest here, but your bias is clouding your rationality. Algae biodiesel is a great idea and I applaud your pursuit of it and wish you much success. You have every reason to be biased in favor of algae biodiesel, but it is very myopic to say that other technologies do not also have their value in solving the overall economic problem. You seek for a replacement to petroleum, while I would prefer a diversification of our energy sources. Any investor knows the value of diversification, surely you do too.
 
  • #112
mheslep said:
Commuters are not a small portion, they are the majority share of transportation fuel use.


www.calcars.org/epri-driving-solution-1012885_PHEV.pdf
Im skeptical of that figure, 60% must refer to transportation fuel use only (65% of the total). Even so, 30-40% relief from oil would change the energy situation dramatically in net importing countries.

Hmmm, sure enough, if we only consider gasoline consumption, we only get about 4 gallons per household per day. So if we look at typical commutes [edit: avergage commutes, not the same], people are only using a fairly small amount of energy. However, I still see some problems. That average does not imply that people who drive great distances can use stored electric energy. So while the people who drive only a few miles to work can use it, the people who cannot are not reflected by the average number.It may be that the majority of gasonline is used by a fairly small percentage of the commuters, in which case we may see little impact on demand. Next, we buy crude, from which we get, gasoline, diesel, heating oil, kerosine, etc. So, ironically, the amount of crude required is not reduced by simply reducing the demand for gasoline. Of course I guess we could just go into the refining business and sell gasoline to Mexico or Canada, if we didn't have a generally increasing demand beyond the gains.
 
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  • #113
DaleSpam said:
I'm going to call "BS" here. Unless you were in a coma between the gas shortages of the 70's and now, then you are well aware that petroleum has been unbeatably cheap for most of that time.

Oh please, this has been the holy grail of battery technology for decades. You are simply unaware.

Don't you think there is motive for a $2 laptop battery? It is the same problem. Think about it. Using our best state-of-the-art, it cost typically $100 to power your laptop with a battery. How does that compare to the energy requirement of a car? Also, my laptop batteries start getting weak within a year of use.

The Tesla essentially uses laptop batteries.
 
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  • #114
If I seem biased, it is only because I think it the problem is critical and that there are no simple solutions. We can certainly do things to help lessen the pain, but we have been hearing promises for decades that have never panned out - the same ones that we are hearing today. And the oil problem is not new; even when the price was low, anyone paying attention knew that the situation would eventually become critical. And this was all true long before I ever heard of the algae option.

What has changed is that after decades of failed promises, I realized that there were no substitutes for oil. In fact it was personally devestating to come to this realization. Until algae came along, I had all but lost hope.
 
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  • #115
Astronuc said:
[A little later in the article:
I'm not sure about that, since the fog rolling in over San Francisco and Golden Gate bridge contains - sea salt! And why use cold water - perhaps it's less saline.

Yes, I considered including that, but it is just another promise. I think the systems going online will be standard RO. Also, in California, they are planning to treat waste water, and then use it for human consumption.

Given that we find water shortages or dwindling supplies in many areas of the US, we can expect large additional demands on the grid to help provide clean water to population centers.

Nuclear can play a role, but it is not a solution by itself. Part of the solution is conservation and efficiency. Nuclear suffers from the inherent limitations of the efficiency of the Rankine cycle (~34-37% efficiency). Higher temperatures can be used in some advanced designs, but there are materials degradation issues that challenge the economics, reliability and safety.

With the technology that we have today, nuclear energy cannot replace oil. That is a simple fact. And what annoys me greatly is that by making nuclear an issue within the context of the oil problem, as McCain has done, we are only chasing our tails.
 
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  • #116
Ivan Seeking said:
With the technology that we have today, nuclear energy cannot replace oil.
It doesn't need to replace oil! Have you completely missed my point?

What we need is diversification, alternatives, options, choices, ... not a replacement.
 
  • #117
We are discussing our options, and we have few. There is only one that even promises to replace the energy obtained from oil and that can be used for transportation at an affordable price.

Diesel cost about $5 a gallon now. This affects everything from the price of food, to the price of widgets from China.

Nuclear power can't put food on your table. That requires diesel fuel, and lots of it.
 
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  • #118
Something else to remember is that to whatever limited extent we can reduce gasoline usage [or slow the increase in demand] this will not have a significant effect on the price of fuel. That is determined by global markets. So the benefit that we can hope for is that individuals reduce the economic pain of the price of fuel directly. But this will not help reduce the price of food or steel.
 
  • #119
Ivan Seeking said:
We have been through that. The Tesla has probably $50,000 worth of batteries.
The battery cost for plugins is still an issue as I mentioned above, though one can't use the Tesla for cost comparisons; it is a 250HP exotic limited production sports car. A realistic price point at the moment for batteries appears to be about $1k/kWhr:
How much you'll pay for one remains an open question, and one answered by the price of the lithium ion batteries. "They're over $1,000 a kilowatt hour," Tom Turrentine, director of the Plug-in Hybrid Electric Vehicle Research Center at UC-Davis, told Wired.com. "The Volt battery is 16 kilowatt hours. That's $16,000 just for the battery."
http://blog.wired.com/cars/2008/06/bob-lutz-drives.html
Keep in mind also that all electric cars may do without many things found in current ICE cars including the transmission, clutch, flywheel, axles, differentials, driveshaft, universal joints, starter, and alternator.
 
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  • #120
vanesch said:
I have no clue, but I'm amazed by that figure. So I googled a bit and I found this:
...
and:

http://www.fao.org/docrep/w7241e/w7241e05.htm#1.2.1 photosynthetic efficiency
)
Yes as I said max possible (theoretical) efficiency derived from the chemical equation:
CO2 + 10 photons + H2O = CH2O + 1/2O2. (450kJ captured / 1700 kJ light)/mole
which gives 25% efficiency. Unfortunately much of solar radiation is not in usable wavelengths by existing plants, which cuts it down to 11%. Again that's existing plants, and perhaps some engineered organism might be produced in the future that can use more UV and IR.
More text from the FAO link:
Furthermore, fixation of one CO2 molecule during photosynthesis, necessitates a quantum requirement of ten (or more), which results in a maximum utilization of only 25% of the PAR absorbed by the photosynthetic system. On the basis of these limitations, the theoretical maximum efficiency of solar energy conversion is approximately 11%. In practice, however, the magnitude of photosynthetic efficiency observed in the field, is further decreased by factors such as poor absorption of sunlight due to its reflection, respiration requirements of photosynthesis and the need for optimal solar radiation levels. The net result being an overall photosynthetic efficiency of between 3 and 6% of total solar radiation.

vanesch said:
Adding a factor of about 1/3 for the Rankine cycle (steam cycle), we obtain finally of the order of 1 - 2 % solar efficiency. (1/2 is very optimistic, it is only reached in combined gas turbine - steam cycle plants
Well another reason to skip a heat cycle and go straight from solar PVs to batteries and 90% eff. motors. :wink:
 
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  • #121
mheslep said:
The battery cost for plugins is still an issue as I mentioned above, though one can't use the Tesla for cost comparisons; it is a 250HP exotic limited production sports car. A realistic price point at the moment for batteries appears to be about $1k/kWhr:

1 KWHr is 3413 BTUs, say at 80% efficiency for charging, and 80% efficiency at the point of use, but we will be generous and say 90% and 90%. So that leaves us with 2765 BTUs of energy storage for $1000.

We get 125,000 BTUs from a gallon of gasoline at about 25% efficiency, or 31,250 BTUs of output energy.

So it would take $11,000 worth of batteries to get the energy storage and output of one gallon of gasoline.
 
  • #122
mheslep said:
Well another reason to skip a heat cycle and go straight from solar PVs to batteries and 90% eff. motors. :wink:

We don't have the batteries at anything close to an affordable price. You want to bet everything on a technology that has stumped the experts for decades, and just hope that it comes along, this time?
 
  • #123
Ivan Seeking said:
We don't have the batteries at anything close to an affordable price. You want to bet everything on a technology that has stumped the experts for decades, and just hope that it comes along, this time?
"You want to bet everything"? Not me, nor do I see anyone else seriously 'betting everything' on hybrids; current budgets are moving things along nicely. Please take a look at how battery technology has progressed in the last few years before making pronouncements. You should well no someone could point to the 70's/80's Aquatic Species Report and say the same thing.
 
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  • #124
Ivan Seeking said:
1 KWHr is 3413 BTUs, say at 80% efficiency for charging, and 80% efficiency at the point of use, but we will be generous and say 90% and 90%. So that leaves us with 2765 BTUs of energy storage for $1000.

We get 125,000 BTUs from a gallon of gasoline at about 25% efficiency, or 31,250 BTUs of output energy.

So it would take $11,000 worth of batteries to get the energy storage and output of one gallon of gasoline.
Charging efficiency is not relevant for sizing the battery, only to the overall energy usage cycle. Even in the $11k / 1 gallon-equivalent scenario you've drawn we have a usable commuter vehicle - that's more than enough in a 50 mpg equivalent plugin hybrid to go to work/school and back. And that's now with just released technology, in low production numbers. Another 40% improvement or so in energy density/$ looks plausible. As we discussed elsewhere converting that 1 gallon of fuel would have a large impact on US fuel usage, displacing it with electric use.
 
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