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Old 07-02-2013, 06:56 PM   #51 (permalink)
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Well we won't stop burning gas and coal until it's economically unviable. Even if it stops being cheap, were still gonna burn through all our fossil fuels until they're gone. Nothing else matches the power density of gas thats just sitting in the ground, and eventually all it's pollution will be dumped into the atmosphere.

So if you think electric cars pollute more or less than gas cars, the fossil fuels we power them both with are whats "Unclean, at any speed." The question still is can we slow down the "speed" at which we pollute? The way society works, walking and riding bikes while using gas cars as the author suggests, will have little impact. And if we keep on trucking as we do, it'll lead us to a place where we are woefully inept to manage the transition to zero oil.

Renewable energy (wind, solar, thermal, bio) and alternative fuels (such as electric) are the only REAL solution. And maybe someday when all gas is gone they will be the ONLY solution. Electric vehicles are the most practical option as they are able to tie into a zero emmisions grid. You could have Synthetic-Gas or Hydrogen produced from electricity at a energy conversion deficit, or battery electrics.

But you still can't expect to run a renewable energy grid, wasting as much electricity we do today. We still have blackout's even running coal power plants! We will need several things:

Efficient housing and insulation (we throw away so much energy heating in winter and cooling in summer). All that heating will need to be electric when natural gas is gone.

A local agriculture shift, or else a national electric train distribution network. Which doubles for mass transport cross country.

And a rescaling of the automobile to 1-1,400lbs or less. Which drastically halves the mining needed for the battery, and the metals to build the car.

I'm not sure if ethanol or Biodiesel can have the production needed without displacing food production. I really only see planes and shipping boats being powered by them in the future.


How much better if he championed these solutions? Instead of coming to the misguided conclusion that Electric cars will/cannot save the environment. That does no good, neither does his solution that we should just keep driving our gas cars.

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Old 07-02-2013, 07:30 PM   #52 (permalink)
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He may have toured a combined cycle plant.

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Originally Posted by ConnClark View Post
I'm calling BS on the 50% efficiency claim! peak steam cycle efficiency with today's top of the line super heated steam plants is 40% maximum. That is about the thermal dynamic limit. To exceed that you have to go to a binary vapor cycle (biggest was just 40MW) or Kalina cycle (of which are currently only small scale up to 3.6 MW).
As I mentioned earlier in the thread, a gas turbine ( Brayton cycle ) can feed a steam turbine ( Rankine cycle ) to exceed the 42% Carnot cycle theoretical limit. It is done regularly on some of the Navy ships ported here in San Diego. I am quite sure it is much more widespread in its use. A friend of mine is a mechanical engineer in the installation and retrofit of these systems. He says these combined cycle systems can reach and exceed 50% efficiency even when using the gross lower heating value of the fuel oil. Use of the relatively low temperature output steam is found in crew comfort heating and sea water purification, among other processes.

On land, both General Electric and Westinghouse have Combined Cycle generating facilities that exceed the Carnot limit even when energy for fuel cleaning steps are taken into account. These plants are in the range of 250 - 500 MW and above.

The plant that RedDevil toured may have been an early triple cycle plant. The gas turbine ( at roughly 1400 deg C ) feeds the bottoming cycle steam turbine ( 800 deg C ) which then feeds a final bottoming cycle Kalina type turbine ( ammonia/water refrigerant at 200 - 300 deg C ). The final bottoming cycle will only capture a few percent of the wasted heat energy, but it can push the combined cycle efficiency well over 50% - thus allowing for losses through transmission - and the claimed delivery efficiency.

Current developments are attempting to add bottoming cycles that use refrigerants that expand in the 100 - 200 deg C range to absorb more lost energy. Finally, the application of Sterling engines to the low 100 deg C exhaust stream is being looked at.

Yes, it all adds cost and complexity. But, as most emissions are based on an amount per KWH produced, and greater efficiency adds profit, power generators will move in this direction.
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Old 07-02-2013, 08:05 PM   #53 (permalink)
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Quote:
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The efficiency of 33% is the efficiency of a typical Rankine cycle power plant (where most electricity is generated in the US).
Not if you look at actual data. Yes, there are some older plants at about that level. Newer coal-fired plants are closer to 40%, while a combined-cycle gas turbine plant can be about 60% efficient (per Wikipedia: Gas turbine - Wikipedia, the free encyclopedia )

Furthermore, since there is no way to know where any particular bit of electricity is coming from, you need to look at the whole grid. With 20% nuclear and maybe 10% hydro & other renewables, that boosts the overall grid efficiency (of fossil fuel -> electricity) to the 50% range.

Second, IC engines as used in typical passenger vehicles aren't anywhere near 33% efficient, because they are almost always running far from their optimum BSFC.

Third, re lithium and "rare earths". Lithium is fairly common, and readily mined & recycled (far more so than petroleum!), and as someone has already stated, you need only a few pounds per vehicle, vs many tons of gasoline consumed over a vehicle lifetime. So-called rare earth elements actually aren't all that rare, either.

Just for interest, my Insight gets about 70 mpg. In 140K miles of driving, that's 2000 gallons of gasoline, about 6 tons. Since only about 30% of crude oil can be converted to gasoline, that's close to 20 tons of petroleum burned over a modest automotive lifetime.
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Old 07-02-2013, 11:26 PM   #54 (permalink)
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Quote:
Originally Posted by sheepdog 44 View Post
How much better if he championed these solutions? Instead of coming to the misguided conclusion that Electric cars will/cannot save the environment. That does no good, neither does his solution that we should just keep driving our gas cars.
We shouldn't. Well... ideally.

Personal mobility doesn't have to be tied to the motorcar. Those of us in Asia are only now starting to see mass movement to motorized four-wheel mobility, but we've been doing public transport and motorcycles for ages. 60-90 MPG... could be much better with aero-fairings and more efficient motors... but the upfront costs and lifetime costs are much smaller than cars.

As prosperity increases, the desire for cars increases. Even with large fuel taxes and expensive middle-eastern oil. And the desire for suburbanization also increases.

While living out in the suburbs is nice, having a huge mass of people wanting to move out into the country while working high paying city jobs all over the world doesn't bode well for oil conservation.

Urban living (if you work in the urbs) is energy-efficient. And it lowers the need for motorized transport. Especially if you set it up to be pedestrian-friendly, like Singapore. It won't be the answer for everyone, and people still need to live out in the country to grow food and do... other stuff... (and those that do grow food have the potential for the smallest carbon footprint of all) but it's a good medium term solution to the fossil fuel situation, at least in a world run on international commerce.
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Old 07-03-2013, 12:39 AM   #55 (permalink)
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Interesting article about 14000 abandoned wind turbines

MMM-mmm! Love that clean energy! Especially the part where it says that more energy goes into creation of wind turbines, than is ever recovered by their operation!
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Old 07-03-2013, 01:54 AM   #56 (permalink)
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Quote:
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once the batteries get either twice as cheap, twice as durable or twice as powerful than now there is no holding back the EV's anymore.
Thats not going to happen.

Batteries are not going to get much more powerful. The limits of Pb, Li and Ni chemestry have been realized and are being used to their near full potential.

Batteries are not going to get any cheaper. A Nickel shortaged haulted hybrid battery production, shot Nickel prices over $30/lb several years ago and caused battery production costs to skyrocket. This happened while trying to supply little 1KWH and smaller batteries to a fairly small number of hybrids.
What happens when you increase battery size by about 40 times and try to build the vehicles in much larger numbers?

Lithium is the same way, its too expensive and there just isn't enough for few hundred million people to each have a few hundred pounds of lithium batteries each.
I built my lithium battery by hand and on the cheap from raw, rejected bare AMP20 cells (the industry standard for hybrid and electric car battery construction) at a cost of about $430/KwH just for the cells alone.
Not to mention the MSRP for factory spec cells puts the cost closer to $1000/KwH.
How are people going to afford 20 and 30 KwH battery packs that cost as much as a new gasoline powered car, don't last as long or drive nearly as far between fill ups?

Other wise its nice to think about.
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Old 07-03-2013, 03:16 AM   #57 (permalink)
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Much could be said about the other side of the coin.

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Interesting article about 14000 abandoned wind turbines

MMM-mmm! Love that clean energy! Especially the part where it says that more energy goes into creation of wind turbines, than is ever recovered by their operation!
Early adopted technologies will have failures. The green driven mandates resulted in poorly developed designs that failed too quickly and saw little advantage for repair.

Other wind farms and wind turbine designs are proving much more productive and long lived.

Two of the wind farms mentioned in that Craigslist Rant are still producing. I drive by them regularly and I see new turbines replacing the old. I also drive by new wind farms along the border of Mexico and the USA. Some of them are owned by the local Native tribes. They are pleased by their investments in these modern turbines. They are profitable and relatively trouble free. With composite variable pitch blades, they have the ability to produce electric power in a much larger range of wind speeds.

Yes, there are thousands of turbines that were set up 15, 25 and 35 years ago. And now they are broken. MILLIONS of automobiles break down after less than a decade of use, never returning the investment of energy poured into them. Fossil fueled power plants NEVER return the investment in energy needed to build them because they USE energy in their operation. Niky is spot on in his observations - it is as much going to be a culture change as much as a technology change. We value the automobile enough to accept its waste and pollution. We must do the same for technologies that will help us transition to the future. And in that future, humanity must make do with less.

Wind turbines are improving. They now have higher output and reduced breakdowns. They are able to provide a payback to investors without heavy government subsidies. They are able to payback the energy invested in their production.

It is easy to pick at the scabs of old wounds. It is much more difficult to be a constructive healer. I could sit here and SLAM the automobile for its failures and there would be little good to come of it. I could SLAM fossil fuel for its evils and I would just be spinning in the mud.

What solutions do you think would work for a world that WILL run out of fossil fuels sometime in the near future of humanity?
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Old 07-03-2013, 03:44 AM   #58 (permalink)
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Batteries.

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Originally Posted by oil pan 4 View Post
Thats not going to happen.

Batteries are not going to get much more powerful. The limits of Pb, Li and Ni chemestry have been realized and are being used to their near full potential.

Batteries are not going to get any cheaper. A Nickel shortaged haulted hybrid battery production, shot Nickel prices over $30/lb several years ago and caused battery production costs to skyrocket. This happened while trying to supply little 1KWH and smaller batteries to a fairly small number of hybrids.
What happens when you increase battery size by about 40 times and try to build the vehicles in much larger numbers?

Lithium is the same way, its too expensive and there just isn't enough for few hundred million people to each have a few hundred pounds of lithium batteries each.
I built my lithium battery by hand and on the cheap from raw, rejected bare AMP20 cells (the industry standard for hybrid and electric car battery construction) at a cost of about $430/KwH just for the cells alone.
Not to mention the MSRP for factory spec cells puts the cost closer to $1000/KwH.
How are people going to afford 20 and 30 KwH battery packs that cost as much as a new gasoline powered car, don't last as long or drive nearly as far between fill ups?

Other wise its nice to think about.
Batteries do not have to double in performance. They do not have to double in capacity. They don't have to have twice the life. They do have to improve in cost. But that cost is NOT tied to the raw lithium. Lithium is scraped off the surface of dry lake beds in many places. It is precipitated from mineral wells. It can be bought in it's oxide form for a few dollars a pound. That means the Li batteries costs are largely tied to design/ development and production. Considering how young the technology is, I am confident there will be a considerable reduction in battery costs. A Li battery for a radio controlled car cost 120 dollars US just 10 years ago. The same battery capacity now costs less than 30 dollars. Nope, Lithium isn't expensive. Design and development is. And the batteries are not going to be consumed if recycling continues at the level of lead batteries. There will be enough Lithium to outfit millions of cars.

But, does everyone need a long range pure electric vehicle? I highly doubt it. This is where the idea of a mix of alternatives comes in. I am sure I can get away with a 25 mile range in a commuter car. High performance lead batteries now on the market could fit that need in the mild weather of San Diego. My long bi weekly trips between San Diego and Palm Springs could be covered by a hybrid. My heavy payload company trucks could run on bio fuels. We will not be leaning on only one source of energy in the future. This will reduce the strain on resources such as lithium. We do not need to replace every drop of transport oil with the equivalent in lithium storage capacity.
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Old 07-03-2013, 04:22 AM   #59 (permalink)
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Quote:
Originally Posted by RustyLugNut View Post
As I mentioned earlier in the thread, a gas turbine ( Brayton cycle ) can feed a steam turbine ( Rankine cycle ) to exceed the 42% Carnot cycle theoretical limit. It is done regularly on some of the Navy ships ported here in San Diego. I am quite sure it is much more widespread in its use.
About the most it could possibly be is 25% as that is the amount of energy that is derived from natural gas and oil. Once again that is the most it could be not the likely amount of US energy production.
Quote:
A friend of mine is a mechanical engineer in the installation and retrofit of these systems. He says these combined cycle systems can reach and exceed 50% efficiency even when using the gross lower heating value of the fuel oil. Use of the relatively low temperature output steam is found in crew comfort heating and sea water purification, among other processes.

On land, both General Electric and Westinghouse have Combined Cycle generating facilities that exceed the Carnot limit even when energy for fuel cleaning steps are taken into account. These plants are in the range of 250 - 500 MW and above.

The plant that RedDevil toured may have been an early triple cycle plant.
Not according to their website its not. They say its a straight coal powered steam plant
Quote:
The gas turbine ( at roughly 1400 deg C ) feeds the bottoming cycle steam turbine ( 800 deg C ) which then feeds a final bottoming cycle Kalina type turbine ( ammonia/water refrigerant at 200 - 300 deg C ). The final bottoming cycle will only capture a few percent of the wasted heat energy, but it can push the combined cycle efficiency well over 50% - thus allowing for losses through transmission - and the claimed delivery efficiency.
it may be possible to design a plant like this but nobody has yet. If you can name an example I would like to know of it.
Quote:
Current developments are attempting to add bottoming cycles that use refrigerants that expand in the 100 - 200 deg C range to absorb more lost energy. Finally, the application of Sterling engines to the low 100 deg C exhaust stream is being looked at.
and these low temperature stages might extract an additional 3 to 7% due to the low operating temps. Also a bottoming cycle tends to reduce the efficiency of the upper cycle. At some point a bottoming cycle no longer helps
Quote:

Yes, it all adds cost and complexity. But, as most emissions are based on an amount per KWH produced, and greater efficiency adds profit, power generators will move in this direction.
They aren't likely to spend 50% more to get 10 % more output. The binary mercury vapor cycles proved to be uneconomical to build and operate in the past. Its not like we will see more of them in the future as they are the type of design that could use nuke or coal which provides better than 60% of US electrical needs currently.
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Old 07-03-2013, 04:49 AM   #60 (permalink)
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Interesting article about 14000 abandoned wind turbines

MMM-mmm! Love that clean energy! Especially the part where it says that more energy goes into creation of wind turbines, than is ever recovered by their operation!
Except that it's not true. It depends on the duty cycle of the wind turbine, but the manufacturing energy is typically recovered in less than two years (of a 30+ year life), sometimes less than one.

Whatever we do, we have to do it with the understanding that 9 billion people will be doing it (against the ~1 billion who are doing it now). Another ~3 billion (so 4 billion) of those 9 billion are aiming to do it within the next few decades.

As just one example, car ownership in China is somewhere around 4 cars per hundred people, with 1.5 billion people. In the US, it's about 80 cars per 100 people, with 310 million people. If China were to get to the US rate of car ownership, the additional energy and resources required to do so would be ~4.6 times that currently consumed by the US cars.

If you think they can all be fuelled by oil, try this: I think the US consumes about 20% of global oil production so, just to fuel the extra Chinese cars, without Indian cars, Brazilian cars, Indonesian cars, African cars nor anyone else's in the developing world, global oil production either has to increase by an additional 92% or the fuel consumption of all those cars, in new and old markets, has to drop to compensate.

But can you really see all those people with cars? Of any description, electric or not? Just obtaining the raw materials to build them (and the factories to do so) would be difficult.

That is just the supply challenge and ignores the environmental impact. We will not use all the fossil fuels available because we cannot do so without trashing the civilisation that allows it. We will not permit that to occur and if you listen to what the science is saying re. climate change, the use of fossils fuels will (have to) stop somewhere around the middle of this century.

Yes, that will be disruptive, and alter the current way of life in the developed world. So will continuing to use them. The ability to use fossil fuels is not the only environmental or resource limit that, if reached, will be similarly disruptive.

Yes, there will be renewable energy, in all its forms, yes there will be nuclear energy. There will also be a very different civilisation that uses them because there has to be, and it will happen quite quickly (over less than a century). Most of us alive today will see the end of fossil fuel use.


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