Algal biofuels - the oil of the future? Or not...

[applejuice]

Originally Posted by auroraglacialis

Erm - no offense but I have no idea on the credibility of that site, the design is not really professional to begin with, and I do not have the time to read though about 30 pages of text. The claim is made there, that only 21% of the energy is converted to motion compared to about 35% as I estimated (I think Wikipedia gives a slightly lower number). Both are above the 17% you stated. If the 20% are correct, then the 50% of a diesel engine have to be wrong. I have driven both, diesel cars and otto cycle cars and the savings in gas consumption are not bad, but you do not use 3 times less diesel than regular gas. My current otto cycle car uses about 6 liters per 100 km, a diesel engine car of the same size will need about 4-5 liters of diesel. Even if the energy content in diesel is a bit higher, all of this does not make a 17% vs 50% comparison look realistic.

You have to make a consideration on the conditions on which the engine is running. In the literature, engines are at ideal conditions, it means they are operating in the nominal setup of the factory. In real life, those conditions are not the rule, so that makes efficiency to diminish.
Second, for the information source: it's reliable. If you want a more reliable source, I recommend reading the chapter on Thermodynamics in Sears - Zemansky University Physics or if you prefer, Serway's Modern Physics.

Yet you erote later in the article that coal is only about 30% efficient. Same goes for nuclear BTW - also 2/3 of the energy goes to rivers ususally. natural gas and oil are probably better than that.

I think Nuclear has a slight advantage above all the mentioned, mainly in what emissions concern. Like Aeronautics, the Nuclear Power industry is heavily supervised by regulatory entities around the globe and the waste material is also heavily supervised.
*Note: Fukushima had to go through an earthquake and tsunami way bigger than it was designed for.

In any case, I stick to my assessment that electric cars are at least not more efficient, but rather less compared to many means of transport currently in use.

Oh well...

Oh, I really like distributed power generation a lot better than single point structures. Solar panels on houses and a generator attached to the houses heat generating facility would be much better than what is in place today. I was just wondering about the seeming contradiction

It's a contradictory world

Well, the electric cars do need that power plants and all that goes with it - landlines (lots of copper and metal and land), generators (copper, neodynium), plant facilities, mining (coal, nuclear, gas, oil), transport (fossil fuels) more land (solar, wind), drilling (oil, gas, geothermal)... but that is less than gas driven cars of course. Electric cars however use toxic materials like brake or transmission fluids, oil and grease, rubber tires. The motors need copper and neodynium to work and the batteries require lithium. Especially copper and neodynium are not exactly cheap and abundant, have to be mined and processed. Lithium - I am not decided - it seems possible that there is a desert salt lake that has plenty of it to supply a lot for batteries, but that has to be seen.

Rare Earth Metals are not used to manufacture the bulk of electric motors that are available in the market. Induction motors account for the majority of electric motors that industry builds. The use of Rare Earth Metals is restricted to Direct Current electric motors and generators, where there's the need of a permanent magnetic field. Three - phase, Alternating Current electric motors don't need such materials.

Well, that is hope in a unreliable way. I think it is not so great to rely on "we will think of something" as a basis of where we go, especially if some of the things we think of end up destroying ecosystems or the world we live in. I am sure, oil seemed like a marvellous idea at the beginning of the 20th century and see where it has lead us. Also fertilizers and pesticides lead to a "better file through chemistry" - but ended up poisoning bees, rivers, oceans, groundwater and deplete soil. If new innovastion is created out of desparation or the "need" to replace something else, one is all too willing to accept more of the negative consequences compared to innovation that is optional. If we now "need" electric cars because oil runs out, my prediction would be that this culture will be all too willing to accept a bunch of negative effects in return, because the only other option they look at is oil driven cars and that is also not good.
So the seeming choice is "gasoline cars OR electric cars" - one of them it has to be. No one will like or consider talking about "no cars", because that is unthinkable, a regression, a decline in standard of living or a return to the 19th century or a descent into a "third world country". So "we" stick to debating over which of the cars is a bit less toxic, kills a bit less people, animals, life on this planet - but "we have to have cars, right?"...

But Science has learnt from the mistakes that has made. DDT is no longer used, as a whole range of other materials. Regulatory systems are much better than in the early 20th century and Information Technologies allow the interconnection of research institutes around the globe. I look optimistically at the future because we have better tools to make research and development than a century ago and we are moving to a better vision of economy and development that will take account of environment to preserve it.

[auroraglacialis]

Originally Posted by applejuice

You have to make a consideration on the conditions on which the engine is running. In the literature, engines are at ideal conditions, it means they are operating in the nominal setup of the factory. In real life, those conditions are not the rule, so that makes efficiency to diminish.

Well, still. As I mentioned my personal experience with cars did not show such a great difference between diesel and otto cycle motors. Either real life diesel engines are vastly less efficient as literature says or otto cycle engines are more efficient than the given 20%. I checked a bit the resources I could find and indeed the 20% seem to be valid. So excluding the power generation and starting with electricity at the plant, the energy efficiency of electric cars is probably a bit better than otto engines and in the same order of magnitude as diesel engines (just counting losses in transformers, landlines, battery charging, heat generation during discharge and losses at the motor like heat generation, conductivity, friction. But once you add to that the problem that only 30% of the heat in coal and nuclear plants end up in the grid, then efficiency is really bad.
The argument one can make then is that emmission free power generation would eliminate that problem and it does so in terms of emissions, but it does not improve the efficiency, which is why more power would have to be generated by these means. If they are "free" and"clean", then one could say that there is no problem - just build three times as many power generators and any loss is counteracted, but that was the whole point, I was trying to make, that more power generation would be needed than one would assume by just calculating the energy in oil into a number of windmills.

Second, for the information source: it's reliable. If you want a more reliable source, I recommend reading the chapter on Thermodynamics in Sears - Zemansky University Physics or if you prefer, Serway's Modern Physics.

Haha sorry, I stopped studying Physics at the university and I will not pick it up now again (not to mention that I have my head full of geology and earth science and not really some hours of time left to read Physics books )- I am living with a Physicist though, I could ask him, but for now, I'll take that 20% energy ratio when it comes to what is left to actually move the car (the 35% seem to be what comes out of the motor itself, some is then lost after that).

You calculated 34% efficiency for electric cars starting with heat and a way to transfer that heat with 60% efficiency in a plant (I assume you talk about oil fired plants for comparison with oil fired cars, because coal is less efficient) up to the point it leaves the battery. I assume, that there will be some loss afterwards in actually driving the motor, but that this will not be so much. what is it 90%? As you mentioned different types of motor later, I think IIRC they are different in efficiency - a motor with a permanent magnet is more efficient than one with alternating currents and without a magnet, isn't that right? also, even in an electric car, there will be friction, unless maybe if the motors are directly attached to the wheels (which I remember is not always possible because one has steering wheels and also electric motors can not span the whole range from 0 to 100 mph or more with always the same efficiency)

BTW - I will not at all talk about nuclear issues here - I had a debate about that in the Fukushima thread and that is enough. For here, it suffices to say that they are only about 30% efficient while 2/3 of the heat goes into rivers or the air.

Rare Earth Metals are not used to manufacture the bulk of electric motors that are available in the market. Induction motors account for the majority of electric motors that industry builds.

Ok if that is true then, as I said, I think there was an issue about efficiency though, but in any case, copper is still needed for sure. And if the energy is to come from windmills or solar panels, then these need REEs massivly. If the power comes from some REE-free source, that would not be such a big problem.

But I remember reading in some economy section that REEs are in rising demand also because of electric cars... so I am not sure if not a significant portion of them are built with permanent magnets after all...

But Science has learnt from the mistakes that has made. DDT is no longer used, as a whole range of other materials. Regulatory systems are much better than in the early 20th century

The problem I have with this is, that it seems that industrial technology always has to run into a disaster to learn from it and then only adresses that particular issue.
It needed DDT to learn that putting poisons into the environment kills animals (what a surprise), it took big chemical accidents to learn that safety in chemical plants is important (also a big surprise) and it took oil gushin into the gulf of Mexico to learn that - oh wait, no - nothing was learned from that in the past because it happened again and again afterwards, including in 2010. Oh and it takes currently antibiotic resistant bugs to teach that it may not be a good idea to overuse antibiotics.
About everything that lead to the implementation of restrictions, or regulations was a disaster. And all too often, nothing was really learned from these and the same **** happens again afterwards, because the disaster happened in a different country so it does not affect the one in question

All this may be bearable on a smaller scale, like some local ecosystem being harmed by some spill or explosion and as a result worldwide learning takes place (which as I said often is not the case), but with increasing power, the disasters increase. What will it take to learn and adress and regulate the issues with GMOs? All bees dying off or some plant getting lateral gene transfer and develop into a poisenous invasive species that we then battle for decades? Or GMO bacteria that cause massive effects? And what about nanotechnology - will we learn that it has to be watched once we find that the fish in the ocean die because they took them in? These are no real scenarios - Imade them up because I do not know, but with most things that were developed, some disaster happened before safety was improved and I do not know if that tactics is good for the technologies of the 21st century.
Exxagerated speaking, how can we implement safety regulations and learn from the mistakes when the disaster included the destruction of this planet, the ecosphere, all humans or civilization?

[applejuice]

Originally Posted by auroraglacialis

Well, still. As I mentioned my personal experience with cars did not show such a great difference between diesel and otto cycle motors. Either real life diesel engines are vastly less efficient as literature says or otto cycle engines are more efficient than the given 20%. I checked a bit the resources I could find and indeed the 20% seem to be valid. So excluding the power generation and starting with electricity at the plant, the energy efficiency of electric cars is probably a bit better than otto engines and in the same order of magnitude as diesel engines (just counting losses in transformers, landlines, battery charging, heat generation during discharge and losses at the motor like heat generation, conductivity, friction. But once you add to that the problem that only 30% of the heat in coal and nuclear plants end up in the grid, then efficiency is really bad.

I forgot to mention a fundamental thing about the diesel motor. Given the high compression ratios for the Diesel cycle, the construction of the engine has to be very robust. This adds weight and there's the difference. More weight, more power needed to move the pieces. That's why Diesel engines are mostly used in trucks and heavy vehicles, where torque at low speeds is needed and the required power is high.

The argument one can make then is that emmission free power generation would eliminate that problem and it does so in terms of emissions, but it does not improve the efficiency, which is why more power would have to be generated by these means. If they are "free" and"clean", then one could say that there is no problem - just build three times as many power generators and any loss is counteracted, but that was the whole point, I was trying to make, that more power generation would be needed than one would assume by just calculating the energy in oil into a number of windmills.

Yes, efficiency should be the priority. Unfortunately, the First Industrial Revolution has defined the technology that we use, especially concerning heat machines. When the Second Industrial Revolution came with the invention of the electric motor, the basis was already settled on the steam machine and engineers had to work on it. It would have been better if the Second Industrial Revolution had changed the whole scheme of generation, but unfortunately didn't happen. We are struggling with outdated technology in strategic areas. As an example, after WWII, Japan was completely devastated, but that gave them the unique opportunity to build their industry based on new technology, the rest is history. Developing countries are in a unique position, if their development roads are managed correctly, they could have brand new, more efficient, industry, but...

Haha sorry, I stopped studying Physics at the university and I will not pick it up now again (not to mention that I have my head full of geology and earth science and not really some hours of time left to read Physics books )- I am living with a Physicist though, I could ask him, but for now, I'll take that 20% energy ratio when it comes to what is left to actually move the car (the 35% seem to be what comes out of the motor itself, some is then lost after that).

don't worry too much about it, our numbers are converging.

You calculated 34% efficiency for electric cars starting with heat and a way to transfer that heat with 60% efficiency in a plant (I assume you talk about oil fired plants for comparison with oil fired cars, because coal is less efficient) up to the point it leaves the battery. I assume, that there will be some loss afterwards in actually driving the motor, but that this will not be so much. what is it 90%? As you mentioned different types of motor later, I think IIRC they are different in efficiency - a motor with a permanent magnet is more efficient than one with alternating currents and without a magnet, isn't that right? also, even in an electric car, there will be friction, unless maybe if the motors are directly attached to the wheels (which I remember is not always possible because one has steering wheels and also electric motors can not span the whole range from 0 to 100 mph or more with always the same efficiency)

Yes, I was using a Natural Gas - combined cycle power plant, usually about 55% - 60% at full power. And, yes, 90% is a very good approximation for the efficiency from the battery to the motor. If correctly sized, the efficiency could reach about 95% for an induction motor. Regarding different types of motors and efficiencies, DC motors are popular in the world of control and automation, they can be controlled very precisely and their construction is simpler. Their efficiencies are low, compared to an induction motor (50% is typical). That's because they use carbon brushes to transfer electricity to the rotor, and in the case of permanent magnet motors, the magnetic field is constant and cannot be changed. That leads to magnetic saturation which can, actually, brake the motor almost instantly and damage important equipment.

Ok if that is true then, as I said, I think there was an issue about efficiency though, but in any case, copper is still needed for sure. And if the energy is to come from windmills or solar panels, then these need REEs massivly. If the power comes from some REE-free source, that would not be such a big problem.
But I remember reading in some economy section that REEs are in rising demand also because of electric cars... so I am not sure if not a significant portion of them are built with permanent magnets after all...

One thing that most people don't know is that hybrid cars use DC motors with permanent magnets (that's why the demand for REE has risen). The reason for this election is that they're simpler, the control electronics associated with them is relatively basic and they can be used as generators (the regenerative part of the braking is achieved through the reversal from motor to generator) without external charge sources. The trend in electric cars is to use the three-phase, AC induction motors in pure-electric cars. Electronics allows to run an AC motor with a battery. AC induction motors are, probably, the most fascinating machines ever built. Simple, quiet and very efficient, mechanically and electrically speaking.

The problem I have with this is, that it seems that industrial technology always has to run into a disaster to learn from it and then only adresses that particular issue.
It needed DDT to learn that putting poisons into the environment kills animals (what a surprise), it took big chemical accidents to learn that safety in chemical plants is important (also a big surprise) and it took oil gushin into the gulf of Mexico to learn that - oh wait, no - nothing was learned from that in the past because it happened again and again afterwards, including in 2010. Oh and it takes currently antibiotic resistant bugs to teach that it may not be a good idea to overuse antibiotics.
About everything that lead to the implementation of restrictions, or regulations was a disaster. And all too often, nothing was really learned from these and the same **** happens again afterwards, because the disaster happened in a different country so it does not affect the one in question

All this may be bearable on a smaller scale, like some local ecosystem being harmed by some spill or explosion and as a result worldwide learning takes place (which as I said often is not the case), but with increasing power, the disasters increase. What will it take to learn and adress and regulate the issues with GMOs? All bees dying off or some plant getting lateral gene transfer and develop into a poisenous invasive species that we then battle for decades? Or GMO bacteria that cause massive effects? And what about nanotechnology - will we learn that it has to be watched once we find that the fish in the ocean die because they took them in? These are no real scenarios - Imade them up because I do not know, but with most things that were developed, some disaster happened before safety was improved and I do not know if that tactics is good for the technologies of the 21st century.
Exxagerated speaking, how can we implement safety regulations and learn from the mistakes when the disaster included the destruction of this planet, the ecosphere, all humans or civilization?

Unfortunately, disasters are bound to happen because we are humans, we are prone to make mistakes, sadly. One way to prevent disasters is to develop autonomous systems that won't depend on human input... but those systems will be developed by humans so...

[Human No More]

Originally Posted by auroraglacialis

I do not understand - you could either use larger batteries that have to be changed with a machine and not by manually lifting it out - or you could put in a dozen of the smaller ones, easily accessible in some way. These are technicalities.

Today's electric cars use huge batteries that can not be easily accessed at all. Requiring access without removing a significant portion of the structure (such as the rear seats in most cases) means a significantly smaller available space, the range will be lower for the same energy density of battery - another reason current battery technology is insufficient.

That I also do not understand - you always return one battery in exchange for a new one. Like camping-gas bottles. And as the exchange stations could recharge the batteries themselves, the only reason for them to be transported would be for recycling. Of course areas with higher demand need larger stocks or more powerful rechargers. Again, this is all within the technical possibilities, the reason it will not happen are sitting in many other places.

-Many people drive to place X, batteries run out and get replaced
-All/most batteries at X are charging, there are none available, people who arrive will not be able to continue.
-Some routes are travelled far more regularly than others and will see a much higher turnover.

Well, one of the major obstacles towards using these intermittent energy sources is that the base load is fulfilled by plants that cannot adapt quickly. If they would be able to shut down when wind comes online, that would be a lot better then.

That defeats the point of having a baseload. Gas turbine-based power plants can react quickly, but most can not.
Wind is completely unsuitable for use as a baseload due to being unreliable in both frequency and level of energy, and you are confusing peaks in demand with supply.

Average output from wind was 27.18% of metered capacity in 2009, 21.14% in 2010, and 24.08% between November 2008 and December 2010 inclusive

...At each of the four highest peak demands of 2010 wind output was low being respectively 4.72%, 5.51%, 2.59% and 2.51% of capacity at peak demand.

Hydroelectric storage only provides a few minutes of released power (and several hours to reset, drawing power all that time) - it is used to compensate for sudden load spikes such as advert breaks in popular TV programmes (yes, these do cause demand spikes, as people go to do things like put food or kettles on) or for the increased startup power required by many things after power failure (lighting is one of the biggest examples there). they are completely unsuitable for dealing with high/low demand periods of the day.

I'm not sure where you get your information from, but both nuclear and coal can change output levels, although slower than gas turbines (fastest) or oil - while geothermal has a fixed capacity, it can output at a lower level if required.

Regarding subsidies - all energy is subsidized usually in some way or another (and if it is only a reduced tax, cheap government loans or government financed R&D). In Germany, coal is subsidized to keep the coal workers in their jobs, nuclear is heavily subsidized, there are few taxes and the state paid for a lot of the R&D and the research on the waste storage, solar/wind/biogas is subsidized by giving the owners a minimum price per kWh. I am not so firm about hydro, geothermal or natural gas, but I suspect that they also get some subsidies.

Here, as I said before, wind is so heavily subsidised that they can afford to sell the actual power at a loss per kWh (and would just be running the turbines without generating if that still attracted a subsidy, as there are operation costs inherent in connecting to the grid). There are no subsidies for nuclear or coal, both of which remain highly profitable form their actual energy, and there are subsidies for hydroelectric, but nowhere near the level of wind. Solar is subsidised but only to a small degree due to lack of viability, and it remains the most expensive energy type by a factor of around 20.

There is a reason why a lot of the energy generation is originally state owned, because it used to be a business that cannot make profit unless the people all have to pay more.

Do you apply the same logic to telecommunications that they are unprofitable because privatisation was only relatively recent? or toll roads, or utilities such as water? Most infrastructure was originally state-owned but generally not well managed as a result.

[auroraglacialis]

Originally Posted by Human No More

Today's electric cars use huge batteries that can not be easily accessed at all

Well, that is a technical challenge - maybe cars have to look very different to adapt to that kind of technology.

-Many people drive to place X, batteries run out and get replaced
-All/most batteries at X are charging, there are none available, people who arrive will not be able to continue.
-Some routes are travelled far more regularly than others and will see a much higher turnover.

If there are sudden urges of many people driving in one place, yes, that would be a problem and the infrastructure would have to predict that. Like if there is a football event or a festival. But that is an organizational problem that is not without solution and is probably the exception. And it would only be a problem if X is far enough away for all people driving there to use X as a recharge point.
The last point in the list is no problem because on that routes simply more storage and recharge capacity would have to be set up while in other areas less would be needed.

Overall, I see electric cars as a supplement only anyways - more transport should be public in the future, then there would not be massive flocking of people to one place. If there is a festival, people should rather use their cars only to drive to a station and then use mass transport to get there.

There are a crazy amount of ideas how to change the transportation systems, but few are implemented. If we want to keep using individual cars for every transport it would be wasteful and plainly impossible - no matter what kind of car.

That defeats the point of having a baseload. Gas turbine-based power plants can react quickly, but most can not.
Wind is completely unsuitable for use as a baseload due to being unreliable in both frequency and level of energy, and you are confusing peaks in demand with supply.
I'm not sure where you get your information from, but both nuclear and coal can change output levels, although slower than gas turbines (fastest) or oil - while geothermal has a fixed capacity, it can output at a lower level if required.

There is a nice plan by greenpeace for Germany and some other institutes are also thinking of ways to make a change towards "green" energy in Germany.
The problem is one of perspective. If you take the energy demand as a given and try to fulfil that, then you will need a baseload and flexible additions to that to supply power in peak demands. Then you need slowly reacting coal and nuclear plants as the base and gas and hydro as fast supplements.
If the intention is however to make a shift to renewables, you need to take the intermittent power generation by wind ans solar as a given and then you will need a technology to fill in the gaps. That would then have to be fast reacting means of power generation as well as a network that can redistribute power spikes to distant areas of power demand. This requires efficient (e.g. DC-based) landlines.
Both perspectives are incompatible - if you have a baseload generation, you cannot buffer the intermittend power of wind and solar which means that those technologies are useless, have to be subsidized and acutally paid to not generate power at all. If you want to use them however, the baseload concept has to go away and be replaced by a highyl dynamic system that adapts to the peaks in production from natural sources.

This is why Greenpeace and other envisonmental groups actually do something unexpected and speak out to build more gas powered plants to replace coal and nuclear. Untypical because they ususally do not like fossil fuels. BUT of course the idea is to a) make it a bridge technology until the ways to store energy are improved or the renewables grid grows so that distribution can solve a lot and b) they can with little change also fired by methane from biological sources (waste fermentation).

In addition as I keep saying, demand could be directed in some ways, like turning some machines that are not required to work "on demand" off and on when there is power (washing machines, dishwasher, dryer, battery rechargers - also for cars). That is not enough, but it contributes.

A new energy concept would have to be very dynamic and very different from what is in place now - whic is why I think it will not really happen soon.

Subsidies for wind/solar and coal/nuclear:
The difference is, that subsidies for wind and solar are not intended to be permanent. The idea is to increase the spreading of these, which leads to more manufacturing capacities and cheaper prices. Also the subsidies are needed to bridge over the time when the energy system has not changed yet to provide more dynamic approaches.
We'll not get on one line regarding subsidies for coal and nuclear - so I will not debate this again. I read a lot about coal and nuclear subsidies and the amounts in play, so I think they do exist, if you do not believe so, then we just won't get on one line here.

Privatization:
Yes in fact I do apply this also to telecommunications and all other things like toll roads and water. Specifically water!
For telecommunications, the whole impact was masked by improvements in technology that improved telecommunications overall, so that is a tough example, but for water - MANY german communities are buying back their water supply from the private companies, in other countries specifically South America, the privatization of water supply was devastating for the people living there. The only goal of these companies is to make profit - if that is increased by providing people with better services then it is ok, but usually it is also increased by cutting expenses. In the UK, the railway system was privatized, I am sure you know that story and how it ended with decaying rails. Germany learned from that and intends to only privatize the trains, not the rails, to ensure that they will be there in 20 years. Of course that is however privatizing the gains and communizing (?) the costs

Originally Posted by applejuice

That's why Diesel engines are mostly used in trucks and heavy vehicles, where torque at low speeds is needed and the required power is high.

Oh the nice german little car that used only 3 liters for 100 km was a diesel engine IIRC - so it seems possible enough.

It would have been better if the Second Industrial Revolution had changed the whole scheme of generation, but unfortunately didn't happen.

Would there be more efficient ways to get the energy from coal or nuclear than what is used now? Do these technologies exist? If so, that would be economically very lucrative and certainly woul dbe used, right?

Regarding different types of motors and efficiencies, DC motors are popular in the world of control and automation, they can be controlled very precisely and their construction is simpler. Their efficiencies are low, compared to an induction motor (50% is typical).

And what is the one of the induction motors?
Why do hybrid cars use motors that are only 50% efficient - the benefit of generating electricity during decelleration cannot make up for that, the goal to have a high mileage is not served (a prime argument for buyers) and the little bit more electronics to master the more complex induction system are not that expensive. I am doubtful that these explanations work. My take would be that the induction motors are not that much mroe efficient that is is really worth it or that they have other serious drawbacks - IIRC one of them is that they do not give out as much torque, especially at the beginning of the run. There was a plan to build an e-bike I saw that had such an induction motor. The drawbacks were that the DC energy from the battery had to be converted to a carfully balanced AC with quite some considerable loss in power and that you had to start the bike regularly by pedalling because the motor would only work once in movement...

Unfortunately, disasters are bound to happen because we are humans, we are prone to make mistakes, sadly.

this is why I say that some technologies at least are not to be left fot this to happen. They have to be thoroughly developed and carfully tested before application. And maybe some technologies actually exist that are just not for humans to use becaues of the risks. Because if "we" only learn from mistakes and those mistakes are extremely dangerous, but have to happen for the learning to happen, then that is a dilemma...

[applejuice]

Originally Posted by auroraglacialis

Oh the nice german little car that used only 3 liters for 100 km was a diesel engine IIRC - so it seems possible enough.

I'm not saying that it's impossible to have smaller diesel engines, but industry dedicates most of such engines to the high-power vehicle portion.

Would there be more efficient ways to get the energy from coal or nuclear than what is used now? Do these technologies exist? If so, that would be economically very lucrative and certainly woul dbe used, right?

It's very plausible that development of alternative technologies to the steam-carbon generation would have started earlier if the engineers back then had to face with coal shortages. Besides, for them, environment wasn't an issue...

And what is the one of the induction motors?

85 - 95%

Why do hybrid cars use motors that are only 50% efficient - the benefit of generating electricity during decelleration cannot make up for that, the goal to have a high mileage is not served (a prime argument for buyers) and the little bit more electronics to master the more complex induction system are not that expensive. I am doubtful that these explanations work. My take would be that the induction motors are not that much mroe efficient that is is really worth it or that they have other serious drawbacks - IIRC one of them is that they do not give out as much torque, especially at the beginning of the run. There was a plan to build an e-bike I saw that had such an induction motor. The drawbacks were that the DC energy from the battery had to be converted to a carfully balanced AC with quite some considerable loss in power and that you had to start the bike regularly by pedalling because the motor would only work once in movement...

The why are DC with permanent magnets motors used in place of the induction motor in hybrid cars can be summarized as follows:

• Size: Comparatively, you can miniaturize a DC motor with permanent magnet. For example, look at the fans in your computer, those are DC-brushless motors.
• Simplicity: The DC motor can be controlled with simple switching electronics.
• Speed: The DC motor delivers high torque at low motor speeds and low torque at high speeds. The AC induction motor delivers nearly the same torque in the whole range of speeds it can work, reaching the maximum torque near the maximum speed of the motor. This makes the DC suitable for the hybrid car because you need to have maximum torque at very low speeds, like when you're accelerating, then to smoothly transfer the load to the engine as the speed increases. If you were to use an AC motor for the hybrid car, you would need a power inverter and, possibly, a gear box (without considering the size of the AC motor). Here are the torque curves of DC and AC motors:
  DC motor
  
  AC motor
  
  Note the last image, the % of torque is >100% in all cases. That's a nice characteristic of the AC motor. I will explain it if you ask for it.

When a car is fitted with a KERS (Kinetic Energy Recovery System, or "hybrid"), the most suitable motor is a DC motor, because you need maximum torque at low speeds, simplicity for the control electronics, small size and the enormous advantage of having a generator and a motor in the same package with no modifications at all.

this is why I say that some technologies at least are not to be left fot this to happen. They have to be thoroughly developed and carfully tested before application. And maybe some technologies actually exist that are just not for humans to use becaues of the risks. Because if "we" only learn from mistakes and those mistakes are extremely dangerous, but have to happen for the learning to happen, then that is a dilemma...

Well, that's how we humans are, in fact, I think that every intelligent life form would act the same: trial and error and then learn from it.

[auroraglacialis]

Originally Posted by applejuice

It's very plausible that development of alternative technologies to the steam-carbon generation would have started earlier if the engineers back then had to face with coal shortages. Besides, for them, environment wasn't an issue...

Oh certainly. I was thinking you were referring to a better and more efficient way to build these machines. Because fossil fuels are just very cheap energy up to now and there is not really an efficient way to get that energy. 30% is really ridicolous. If a wind turbine had that, it would never be able to compete at this time.

85 - 95%

Ok, but that is in addition to the 85% of the battery storage in your calculation, so you'd need to add another x.85 to it

Plus maybe the loss at the DC/AC conversion unit which is not neglible.

The why are DC with permanent magnets motors used in place of the induction motor in hybrid cars can be summarized as follows:[LIST][*]Size: Comparatively, you can miniaturize a DC motor with permanent magnet. For example, look at the fans in your computer, those are DC-brushless motors.[*]Simplicity: The DC motor can be controlled with simple switching electronics.[*]Speed: The DC motor delivers high torque at low motor speeds and low torque at high speeds. The AC induction motor delivers nearly the same torque in the whole range of speeds

Ok, but these characteristics apply for all electric cars. Especially weight is a concern for the reach of them and simplicity may be an issue for manufacturers who want to save a few bucks (that should not really be so much of an issue, microprocessors and electronics are cheap).
Most of all, as I was thinking and I remembered correctely, I think that issue with the torque is a problem. How should this be solved in any transportation that uses these motors that do not require magnets? They notoriously accelerate very slowly (and may even have trouble to start moving at all without some starter) and thus are not really a great replacement for the current cars or DC motor cars.

When a car is fitted with a KERS (Kinetic Energy Recovery System

But that recovery system certainly makes up quite a bit for the comparably lower efficiency of the motors, right? (comparing 50% of the DC+the energy gain in kinetic recovery with 85% of the AC)

Well, that's how we humans are, in fact, I think that every intelligent life form would act the same: trial and error and then learn from it.

Actually, I think it is a sign that we as humans may not be so intelligent as we think we are. Because learning from trial and error - a huge number of animals can do that. Just look at pet cats or dogs. If we were truely intelligent as a species, we would be able to learn from other peoples mistakes for once (and not make the same mistakes again just because we think "it was the stupid Russians, what do they know") and also predict and ponder about risks and consequences in advance and then act upon what our supposedly brilliant minds have concluded. And some people do this thinking but the overall action does not reflect that, so as a species at least civilized people do not show that sort of intelligence, reverting to "trial and error", to blind tinkering. Some indigenous people seem to show more hindsight and intelligence there, pondering about "the seventh generation" after them and what the consequences of their own actions are for that generation.
So humans do have some capability for intelligent, preemptive behaviour, but at least the dominant culture does not seem to express this very much.

[applejuice]

Originally Posted by auroraglacialis

Ok, but that is in addition to the 85% of the battery storage in your calculation, so you'd need to add another x.85 to it

Indeed.

Plus maybe the loss at the DC/AC conversion unit which is not neglible.

That's a good point. The process of transforming DC power to AC is called Inversion. Before computers got popular, the process was very inefficient. Around 20% efficient. Fortunately, thanks to Electronics, inversion and rectification processes are now quite efficient, an usual number is 80% for both. But that number is increasing. Here at work, the inverters of our UPSs are 99% efficient. Each one is rated at 1000 KVA.

Ok, but these characteristics apply for all electric cars. Especially weight is a concern for the reach of them and simplicity may be an issue for manufacturers who want to save a few bucks (that should not really be so much of an issue, microprocessors and electronics are cheap).
Most of all, as I was thinking and I remembered correctely, I think that issue with the torque is a problem. How should this be solved in any transportation that uses these motors that do not require magnets? They notoriously accelerate very slowly (and may even have trouble to start moving at all without some starter) and thus are not really a great replacement for the current cars or DC motor cars.

The issue with low torque in electric motors is a myth, as is the slow speed of them. Generally, one can model the torque of any electric motor with this simple equation:

T=k V

Where T is the torque and V is the voltage applied to the motor. The higher the voltage, the higher the torque. As shown in the curves, the DC motor has variable torque and speed and the induction motor nearly constant speed and torque. The electric motor reaches its operating speed in a couple of seconds, if not faster. For low voltage motors (usually below 1000 V) it is considered that the operation speed is reached instantaneously. For AC motors, the operation speed depends on the frequency of the feed line and in the DC motors the speed is a function of mechanical load. I will post later the torque and speed of standard AC motors. (right now I can't remember where I put the catalogue).

But that recovery system certainly makes up quite a bit for the comparably lower efficiency of the motors, right? (comparing 50% of the DC+the energy gain in kinetic recovery with 85% of the AC)

KERS was designed as an aid to be used in certain circumstances, like braking and accelerating, not for the long runs, where the system is deactivated. The difference is notorious in short runs, where the KERS is used nearly 50% of the driving time. A DC motor can be turned into a generator without any modifications in the motor and with no requirements in the speed of the rotor (you can have it generating electricity at very, very low speeds). To turn an AC motor into a generator has some requirements, the main is the speed. There's a minimum rotor speed that has to be reached to turn the motor into a generator.

Actually, I think it is a sign that we as humans may not be so intelligent as we think we are. Because learning from trial and error - a huge number of animals can do that. Just look at pet cats or dogs. If we were truely intelligent as a species, we would be able to learn from other peoples mistakes for once (and not make the same mistakes again just because we think "it was the stupid Russians, what do they know") and also predict and ponder about risks and consequences in advance and then act upon what our supposedly brilliant minds have concluded. And some people do this thinking but the overall action does not reflect that, so as a species at least civilized people do not show that sort of intelligence, reverting to "trial and error", to blind tinkering. Some indigenous people seem to show more hindsight and intelligence there, pondering about "the seventh generation" after them and what the consequences of their own actions are for that generation.
So humans do have some capability for intelligent, preemptive behaviour, but at least the dominant culture does not seem to express this very much.

You're right, it seems that most humanity likes to trip on the same stone several times. But I'm an optimistic man...

EDIT: Here is an example of the power and torque of electric motors: a 4 pole, 3 phase, 25 HP motor has a torque of 100 Nm at 1800 rpm. Weight 155 kg. Efficiency: 92.4%
A 100 HP, 4 pole. 3 phase motor has a torque of 398 Nm at 1800 rpm. Weight: 495 kg. Efficiency: 94.5%
*Note, the above motors are Siemens, squirrel cage series 1LG6 with standard construction.
A Toyota 1800 cc 2ZR-FE engine has a rated power of 132 HP and a torque of 174 Nm at 6000 rpm.

[auroraglacialis]

Originally Posted by applejuice

The process of transforming DC power to AC is called Inversion.... 80% for both

Yeah - I remember the inverter for that electric bike produced some temperature...

The issue with low torque in electric motors is a myth, as is the slow speed of them

Electric motors in general I think have high speeds and can have high torque, but AC motors have a limited torque as your graphs show. The problem is, that while accelerating, one needs most torque at the beginning, at low speeds and not so much torque once high speeds are reached. DC motors give exactly that, AC motors not, which makes them less suitable for low speeds and stop-and-go. The latter is also the situation KERS and DC motors are good for.
So overall I would say for city traffic (the majority of individual traffic), DC motors with KERS are better suited for red lights and frequent accelerations, while for long distances, AC motors would be favourable, e.g. for busses or trains. At least that is what I get from this.

Geez, but we seriously strayed from the original topic and got entangled totally in geek talk

[Human No More]

True
Well, with the existence of hybrids today, it isn't implausible to have a system with both.

[applejuice]

Is there any solid indication that algal fuels are going to be better than oil? If we are going to dedicate enormous extensions of land to produce fuel, then the product has to be, at least, as cheap as the oil-derived fuel.

[auroraglacialis]

The point is not so much how cheap it is ut also to have it at all. From my OP the conclusion would be that it cannot do either and thus is a non-solution.

[applejuice]

Right now, it seems that biofuels are like digging a hole to fill another. I think that, if no breakthrough is going to be made in the industry of energy within the next decade, biofuels (wherever they may come from) will certainly have a big role in the energy industry. Not that that is bad, if somehow algae and bacteria are modified to recycle the carbon from the atmosphere and use the available heat as an energy source, then it would be a win-win situation.

[auroraglacialis]

It always depends on if there is an impact of these biofuels that is negative in other ways. As you said to dis one hole to fill another is not a great idea. So to trade carbon emissions for setting vast landscapes under water and potentially other consequences of large scale biofuel production - does it make sense?

Here is a guy speaking out in favour of algae biofuels for example:
(the first half is rather boring if you had biology in college )
IFYOULOVETHISPLANET

I think his main argument is that algae made all the oil we have now anyways and that "we" can grow them in areas that are "useless anyways" like arid areas. What he means of course is that these areas are not yet useable by humans for agriculture or forestry. I have not listened to it to the end yet, but I will. Just wanted to post it here because it is on topic.