Nuclear power won't fix the energy problem

[vanesch]

It could but there are probably better ways.

One problem cited is transportation but this is only a problem if one accepts the current paradigm whereby cars and trucks carry an on-board supply of fuel. If maglev highways were created then a car would only need enough fuel to reach the electrified highways with the added advantage safeguards could be built into dramatically the reduce the amount of road accidents. This and similar systems already works perfectly for trains and trams.

The problem is again that that is science fiction at this moment. We're not talking about solutions in 50 years from now, we're talking about energy policy in the 2 or 3 next decades. It is inconceivable to turn most of the roads into maglev highways, and most of the cars into maglev driven cars in 10 - 20 years time. I'd say that it is 100 times easier to put batteries in cars than to change cars into maglev things. That said, there already does exist a major transportation system that works (or can work) on electricity: trains.

There are 2 major energy problems:
- oil. It becomes expensive, it is in the hands of geopolitically unattractive players, it needs major military investment and interventions which is a source of a lot of terrorism etc... there are plenty of reasons to try to get rid of oil, or at least to have a competitive replacement for oil, so that it doesn't have a monopoly position in the market.
- CO2. In as much as we should take AGW seriously - and for the moment we can't exclude that possibility with any level of certainty - we should seriously cut back on the use of fossil fuels. There was oil of course, but there's mainly gas and coal.

Oil seems to be the major player for the transport sector, and coal and gas are the major players (well, essentially coal) for electricity.

If we do not take the CO2 problem seriously, there's no problem here. Coal can provide plenty of electricity, for hundreds of years to come. There IS a public health problem with coal: the emission of heavy metals, mercury, uranium, etc... but then, this wasn't a problem until now, so the killing of 500 000 people per year for electricity production is socially accepted, in the same way as killing 1 200 000 people per year for transport is socially accepted. (BTW, IMO when you see these numbers, all whining about the danger of nuclear power becomes moot)

The only EXISTING technology, today, which can claim to be able to replace coal and gas potentially ENTIRELY is nuclear. There is no developed country or large region in the world that has demonstrated getting the large majority of its electricity from anything else but coal, gas, or nuclear. Apart maybe from Sweden, which is 50-50 nuclear and hydro.

The only country that has had a major replacement for oil in transportation is Brazil, with its biofuel.

I'm not sure nuclear power is the only way or the best way to provide enough electricity to fulfil our requirements. Essentially the essence of useful energy production is heat and the Earth has plenty of that. I'd have thought we could make far greater use of geo-thermal energy than we currently do. Afterall it basically only requires we dig deep holes in the ground to tap into a practically unlimited heat source.

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

You need adapted geology for that. It isn't sufficient to dig a hole in the ground to get out boiling water (you need boiling water, not hot water). I don't think it is going to be a major player in any case. There are of course a few special places on earth, like Iceland, where geothermal IS a very interesting majority source. But not everybody lives on a mid-ocean rig!

There is also tidal power which is again under exploited despite the advantage of being a continuous source of power unlike solar and wind generation and then there is the potential for far greater use of hydro-electric power.

Although tidal power can be expanded (there is not much of it), I also seriously doubt that this is a serious player, because you need special geography for it. There are only so many coastal areas where the tides are strong enough to allow for a useful tidal plant. You're not going to get hundreds of gigawatts out of that.

Hydro, on the other hand, is almost already completely exploited where possible. I don't think it is possible to double hydro power worldwide.

With both of these techniques, there is a non-negligible ecological impact if done on large scale.

Wind and solar have the IMO extremely difficult problem of intermittency.

In any case, the only non-CO2 technology that has already shown its merit for electricity production is nuclear, and the only practical replacement for oil in the transport has been shown to be biofuel.

Nothing stops us of course from experimenting, and trying out other technologies. But they cannot claim, as of yet, such a success that they can be used as an argument against those technologies that HAVE shown to work. You can't hope to bring to 70% in a few decades a technology that hasn't yet passed somewhere the 30%, and that has worldwide less than a few %.

Things can be different 30 years from now, but in the coming decades, we can't count on any sci-fi to solve the issues ; we have to make plans with something that has already shown its utility. Then maybe, we don't have to. If AGW turns out to be false, and if ~500 000 dead per year remain socially acceptable, then coal can be used for electricity generation. If the oil price continues to rise, then the market will automatically find a solution to that problem. But one can't on one hand, use a public policy worldwide that acts upon the hypothesis of AGW, wants to incite people to use less electricity, bring out penalties for inefficient appliances and cars, and then deny a full and rapid development of the only technology that has shown to be able to replace coal and gas.

 

[vanesch]

However it can't be called sustainable as coal will deplete once.

"Sustainable" doesn't mean: "must have the potential to work indefinitely". The UN definition of sustainable is:

Believing that sustainable development, which implies meeting the needs
of the present without compromising the ability of future generations to meet
their own needs, should become a central guiding principle of the United
Nations,...

from http://www.un.org/documents/ga/res/42/ares42-187.htm

This is a very sensible definition. We don't have to solve the transport and electricity production for 100 years from now, and certainly not 500 years from now. That would be like putting the burden of transportation and electricity (what ?) production of our times in the hands of the people living 100 or 500 years ago. We don't have to solve the problems of the future generations: we have to solve our own. Only, in doing so, we mustn't make such a mess that the problems of the future generations are more involved and their ability to solve them, compromised.

So we may use coal. We may not deplete it. We should think of another solution to what coal is doing for us before we deplete it. As there is still enough for more than 1000 years of coal, we still have time. Oil can be different. We might be depleting it right now.

And of course, if AGW has something to it, we may not take a major risk with the future generations.

 

[mheslep]

I remember.

However,
1) that thing is from 1985, so now it might be more expensive (shall we take nuclear plant prices from beginning of the 80ies ?)
2) it is 2100 MW generating, but only 420 MW pumping

2800 now. They upgraded the '85 turbines a couple years ago - pulled the blades, shipped them back to GE, when they came back - 700MW upgrade.

so if they have to pump (day) as much as they consume (night), you only have 420 MW available, hence about $4,- per installed reversible watt.

That is only for your chosen duty cycle. If you want to look at duty cycle then you'd measure a storage facility by kWh, not W. Regardless of how long the system generates its power rating is still 2800MW.

 

[Andre]

And of course, if AGW has something to it, we may not take a major risk with the future generations.

You are daring me, Vanesch.

I'll get back to that, strongly, but later. A lot of distraction now.

 

[mheslep]

I really don't think so. Laser isotope separation IS working, only it isn't working profitably and on large scale for commercial operation and big volumes and it is difficult to put in place.

Look at http://www.globalsecurity.org/wmd/intro/u-laser.htm

They state indeed that:
"Although LIS appears promising, the technology has proven to be extremely difficult to master and may be beyond the reach of even technically advanced states."
But that's not the point. The point is, can one do this in a country which wants to put all the means to it, in a hidden way. A diffusion, or even a centrifuge plant, is a very big system. You can see it on satellite pictures, you need LARGE quantities of materials etc...

No that is exactly the point. LIS can only produce micrograms of enriched material. To attempt to scale it up to weapons level with the current state of the art would not just be unprofitable it would be impractical to the point of impossibility. Heck, multiplying an LIS setup a million fold might just make it bigger than a centrifuge enrichment facility.

So that seems to work.

In the lab! It is useless as a path to a weapon at the current state of the art.

Now, given that Greenpeace is in there, that might be fear mongering as usual, but give it 20 or 30 years, and I wouldn't say that laser isotope separation isn't going to be THE proliferation issue.

That was my original point. LIF is no bother at present as a proliferation issue and it will likely stay that way unless a technically highly competent, but foolish, state pushes it hard.

 

[mheslep]

I see it this way: First of all, unlike the perfect battery or nuclear fusion, the problems remaining for algae are purely practical; not fundamental. So although I don't mean to minimize the difficulties in large-scale algae to fuel production, and there are plenty, I see nothing more than the typical sorts of engineering problems that I solve every day in order to make a living. What's more, at this time there are no other options, so we have no choice. We HAVE to make it work.

I hope algae-oil works out, it appears to be perhaps the most promising bet. But I have not seen even an attempt made at an argument to defend the claim that there is no other choice.

Just to restate the subject of the thread for late comers: Nuclear power cannot solve the oil problem.

So you claim, and it may be true, but I have not seen a good argument here for that thesis. Saying we don't have viable electric cars is specious. We don't have the required capacity today of algae oil, ethanol, nuclear, fossil oil reserves or any other source, to meet the predicted demand 10 years hence. And nuclear need not replace all fossil oil to solve the oil problem; just replacing imports would relieve the price pressure and availability issues. If you have a good technical argument as to why nuclear/E cars nor anything else but algae will work then I am all eyes.

 

[mheslep]

...Second element is what the systems produce, electricity is fine for many static appliances but it's less suitable for traffic and virtually worthless for aviation.

To remain flying, unless some magic thrust source is develloped, only high energy liquid fuels are usuable nowadays. http://www.post-gazette.com/pg/06229/714268-28.stm using heat, which could be generated with nuclear means. However it can't be called sustainable as coal will deplete once.

So, considering the diversity of supply and demand, it seems that all feasible solutions should be used on the long term.

Just so we know which function needs how much:
US Oil for transportation, yr 2007:
69% (and rising as oil is no longer preferred for E power generation)
http://www.eia.doe.gov/aer/diagram2.html

Transportation breakdown, yr 2002:
light duty vehicles - 61%
commercial light trucks - 2%
heavy trucks - 14%
airplanes - 10%
http://www.eia.doe.gov/oiaf/archive/aeo04/pdf/appa.pdf , table A7

So solve the cars and light trucks problem, possibly w/ plug-in hybrids, and then you'll ample left over for air transport.

 

[Ivan Seeking]

No, you don't seem to understand my point: in the total CO2 balance, not one single gram of CO2 is removed by the algae from the coal burning. Whether you put that coal burning CO2 directly to the atmosphere, or you first put it in algae and then to the atmosphere, it won't make a difference.

Of course, the use of the algae fuel (in a car for instance) will be CO2 neutral: what it absorbed during its growth, is released during the use of the fuel. If that replaces oil consumption, then you win. It is as if the car was working on solar. There's no discussion.
What happens here is that during growth, you remove CO2 from the atmosphere, and during use, you put it back.

But if you now make your algae grow in the CO2 from a coal fired plant, and not from atmospheric CO2, then you do NOT remove the CO2 from the atmosphere, but you will put it in the atmosphere when the algae fuel is burned. What you do then in the end is that you put the CO2 from the coal fired plant, in the atmosphere.

So making algae grow on coal fired CO2 doesn't do anything at diminishing the CO2 exhaust of a coal fired plant. That said, maybe it can stimulate its growth or anything, so if *in any case* that CO2 is going to go in the atmosphere, just as well use it one more time to do something useful. But you cannot say that algae are going to serve as a CO2 scrubber, implying that they would make coal burning clean of CO2 exhaust.

What I am saying is that if we grow algae with coal, we recycle the carbon for use as fuel. So rather than releasing the CO2 from coal directly, it is released when the autos burn the fuel. But it used twice and released once, so in effect we have either eliminated the emissions from coal, or we have eliminated the emissions from autos, but not both.

Close systems would allow for power generation without any emissions whatsoever, but that would not allow for the production of transportation fuels. However, if algae can be made practical for fuel production, the replacement of coal power with closed algae systems is just a step away.

Algae from coal may be a practical intermediate step to an algae energy base. I know it isn't ideal, but it may be needed for economic reasons until the algae market is well established. When we have solved the fuel problem, we can start converting the coal plants to closed algae power systems.

 

[Ivan Seeking]

Algae can be used to remove CO2 from the global system if it is allowed to sink to the ocean floor or is otherwise sequestered. One company was trying to do this with open ocean blooms. In return they hoped to get carbon credits.

 

[GTrax]

What I am saying is that if we grow algae with coal, we recycle the carbon for use as fuel. So rather than releasing the CO2 from coal directly, it is released when the autos burn the fuel. But it used twice and released once, so in effect we have either eliminated the emissions from coal, or we have eliminated the emissions from autos, but not both.

Er.. "recycle the carbon for use as fuel" ? OK - I maybe just don't understand enough about the algae process energy balance. At what stage in the process did the algae contrive to put hydrogen back with the carbon to result in anything we might call "fuel"?

I am happier in thinking that the worlds best, most evolved, sun-seeking, space sharing, self propagating solar energy collectors with a built-in CO2 collection and long-term storage mechanisms are anything with leaves! If we ferment them after, and burn the product, we are at least neutral, but we should strive to repair some of the last two centuries worth of damage.

Could diverting some energy to desalination, and desert reclamation be a positive thing?

 

[Ivan Seeking]

Er.. "recycle the carbon for use as fuel" ? OK - I maybe just don't understand enough about the algae process energy balance. At what stage in the process did the algae contrive to put hydrogen back with the carbon to result in anything we might call "fuel"?

That is just about all that algae does. It absorbs CO2 and water to make a high quality fuel, using the energy from sunlight. It can be used to make ethanol, biodiesel, or hydrogen, but for now biodiesel is the best option.

 

[vanesch]

What I am saying is that if we grow algae with coal, we recycle the carbon for use as fuel. So rather than releasing the CO2 from coal directly, it is released when the autos burn the fuel. But it used twice and released once, so in effect we have either eliminated the emissions from coal, or we have eliminated the emissions from autos, but not both.

Again, you didn't "use it twice". You made biofuel for cars. So the cars are not going to emit a net amount of CO2, that's true. I thought that was the whole business: make biofuels for cars.

What doesn't make a difference at all, is whether those algae have been grown in the atmosphere, or in the exhaust of a coal fired plant. The coal fired plant puts, at the end of the day, a certain amount of CO2 in the atmosphere.

Close systems would allow for power generation without any emissions whatsoever, but that would not allow for the production of transportation fuels. However, if algae can be made practical for fuel production, the replacement of coal power with closed algae systems is just a step away.

Yes, that's using biofuel to make electricity. But I don't see what coal has to do with that ?

Algae from coal may be a practical intermediate step to an algae energy base. I know it isn't ideal, but it may be needed for economic reasons until the algae market is well established. When we have solved the fuel problem, we can start converting the coal plants to closed algae power systems.

Really, I don't see why you call that "algae from coal". They would grow just as well without the coal, no ? Algae make biofuel. With that biofuel, you can drive cars, or drive a biofuel power plant. All that is CO2-neutral in the long run. If you burn coal, you add CO2 to the atmosphere, irreversibly. The quantity of coal you've burned, will end up in the atmosphere.

 

[B. Elliott]

I've been following this thread from the beginning and just want to make sure I'm seeing the overall picture correctly; The algae would just be a way of harnessing the CO2 to use later?

Wouldn't progressing towards power production which (either now or eventually) emits no CO2 whatsoever, be the better approach?

 

[Ivan Seeking]

Again, you didn't "use it twice". You made biofuel for cars. So the cars are not going to emit a net amount of CO2, that's true. I thought that was the whole business: make biofuels for cars.

What doesn't make a difference at all, is whether those algae have been grown in the atmosphere, or in the exhaust of a coal fired plant. The coal fired plant puts, at the end of the day, a certain amount of CO2 in the atmosphere.

The point is to make fuel for autos. But first: We did use the carbon twice, didn't we? Once to generate electricity from coal, and once to power a car?

The motivation for this is that it is easier to grow algae at the required rates if we provide supplemental CO2. Ideally this would all come from natural sources, but we can certainly use the CO2 from coal plants to get a jump start. Again, my thinking is that the sooner we can become profitable making fuel from algae, the better, and using coal fire exhuast is an excellent means to that end. But again, this would only be an intermediate step, because as you have shown, it doesn't solve the carbon problem entirely - we are still releasing the carbon from the coal. But we would not be releasing the carbon that would otherwise come from petroleum, so it is a net gain if we look at both the autos and the coal plant.

Yes, that's using biofuel to make electricity. But I don't see what coal has to do with that ?

Given the above motivation to use the CO2 from coal fire to quickly grow algae for biodiesel production, we are left with a coal plant exhausting into a field of semi-closed algae bioreactors. As soon as the algae industry evolves enough to produce fuel economically from ambient or natural sources of CO2, and in order to avoid releasing any more carbon from coal by making fuel for cars, we now replace the coal with algae biomass, or algae oil, and completely close the system. In principle, nothing goes into or out of the system except the end product of electrical power. The logic for this is that not only do we already have a bioreactor system next to the coal plant, but also that the plant can likely be converted to run on substitute fuel sources. So I am really just thinking of the economics here.

Really, I don't see why you call that "algae from coal". They would grow just as well without the coal, no ?

So the answer here is no. Algae can be grown without additional CO2, but it can be grown much more quickly and profitably if we have a source of CO2 beyond the ambient levels.

Algae make biofuel. With that biofuel, you can drive cars, or drive a biofuel power plant. All that is CO2-neutral in the long run. If you burn coal, you add CO2 to the atmosphere, irreversibly. The quantity of coal you've burned, will end up in the atmosphere.

Yes, we do agree, but looking at this with an eye to the economics, using coal exhaust may help to move things along more quickly as the industry struggles to take hold. Presumably, carbon taxes will eventually make coal power obsolete, and we can run everything on pure algae power derived from ambient, or would-be ambient CO2, such as from decaying biomass.

 

[Ivan Seeking]

I've been following this thread from the beginning and just want to make sure I'm seeing the overall picture correctly; The algae would just be a way of harnessing the CO2 to use later?

Wouldn't progressing towards power production which (either now or eventually) emits no CO2 whatsoever, be the better approach?

Hopefully I have explained my thinking in the post above. We don't have to have additional CO2 [beyond ambient] to grow algae, but it may help to get the industry started by making it more economical. Ultimately, if we can produce cost competitive fuels from algae using only ambient CO2, the fuel becomes carbon neutral - we only release into the atmosphere the carbon that was absorbed from it in order to grow the algae. So at that point we are not releasing any "new" CO2.

It is also possible that with a little more innovation, we will find that the incident solar flux and the ambient temperatures are the only limiting factors for algae growth, and we won't need the additonal CO2 to be profitable. But right now the struggle is to make algae based fuels profitable as quickly as possible. If we can do this while only solving part of the carbon problem initially, IMO we are still way ahead of where we are today.

Again, it appears that we have no other options to oil. And we won't make the change until the economics work. Ultimately, energy markets are driven by price and not by what makes sense, or by what we SHOULD do, so we have to be competitive in order to have any chance at all of success.

Eventually the price of fuel may be high enough that this will all be moot. Even the worst bioreactor designs appear to be profitable at $15 to $20 a gallon for oil.

We want to solve the carbon problem; there is no argument from me on that one. But we also have to think beyond carbon. If we don't solve the oil supply problem, and soon, carbon may be the least of our concerns. Already we have seen rioting and mass protests because of the price of oil, and India and China are coming online quickly; in the case of China, more quickly than we had hoped.

 

[Ivan Seeking]

The coal plants will be there whether or not we start building nuclear plants.

 

[vanesch]

T
The motivation for this is that it is easier to grow algae at the required rates if we provide supplemental CO2. Ideally this would all come from natural sources, but we can certainly use the CO2 from coal plants to get a jump start.

Ah, I didn't understand that it was somehow easier to grow algae with extra CO2.
A bit like plant growth in an aquarium, then ?

So your reasoning is: given that there will be still for some time coal fired or gas fired plants that *in any case* will put out a flow of CO2, let us just make use of it in the beginning to get the algae grow quicker. That makes sense.

Of course, there's a minor danger there on two levels: first of all, coal fired plants usually don't reside at the seaside (or do they ?), and second, one might concentrate on a species of algae (natural or bio-engineered) which are optimized to work in high-CO2 environments, which might not be adapted to atmospheric conditions. But I agree that these are minor considerations.

Given the above motivation to use the CO2 from coal fire to quickly grow algae for biodiesel production, we are left with a coal plant exhausting into a field of semi-closed algae bioreactors. As soon as the algae industry evolves enough to produce fuel economically from ambient or natural sources of CO2, and in order to avoid releasing any more carbon from coal by making fuel for cars, we now replace the coal with algae biomass, or algae oil, and completely close the system. In principle, nothing goes into or out of the system except the end product of electrical power. The logic for this is that not only do we already have a bioreactor system next to the coal plant, but also that the plant can likely be converted to run on substitute fuel sources. So I am really just thinking of the economics here.

That makes sense. But I think one should first concentrate on replacing oil for transport, before replacing coal for electricity. Now, if the boom is so quick that one can do it "all at once", then I don't mind. However, if growth is slow, I'd give preference to replacement for oil for transport, simply because there are no genuine alternatives available at this moment, while there is nuclear available for electricity (technology-wise).

In summary, if it takes you 10 years to switch everything (electricity + transport) to algae biofuel, then go ahead. If it takes you 40-50 years, then I'd give preference to algae for transport, and nuclear for electricity, because otherwise we will still have 3 or 4 decades of coal ahead.

So the answer here is no. Algae can be grown without additional CO2, but it can be grown much more quickly and profitably if we have a source of CO2 beyond the ambient levels.

This is what I hadn't figured out.

 

[NeoDevin]

Isn't algae oil basically just an efficient `battery' for solar power?

Which is more energy efficient, algae or solar cells?

 

[vanesch]

Isn't algae oil basically just an efficient `battery' for solar power?
Which is more energy efficient, algae or solar cells?

You are right that algae are a kind of battery for solar energy (just as fossil fuels are, in fact).
Solar cells aren't a battery for solar energy, they are an immediate conversion. I guess they are way more efficient still than the cycle: sunshine - algea growth - oil production - oil burning - electricity, but algae have the big advantage of producing oil when you can use it.

 

[NeoDevin]

Solar cells aren't a battery for solar energy, they are an immediate conversion. I guess they are way more efficient still than the cycle: sunshine - algea growth - oil production - oil burning - electricity, but algae have the big advantage of producing oil when you can use it.

I know solar cells aren't a battery. I meant to ask which was more efficient at converting solar energy to a useable form (electricity/chemical), which you answered anyways. (Has an actual comparison been done though?)

 

[GTrax]

Thanks Ivan
(I didn't know much about the algae)

That is just about all that algae does. It absorbs CO2 and water to make a high quality fuel, using the energy from sunlight. It can be used to make ethanol, biodiesel, or hydrogen, but for now biodiesel is the best option.

The key thing there is that at some stage, the algae receives energy from sunlight., and does something convenient.

So OK, we can expose algae farms to sunlight to do something convenient (take up CO2 put out by all the worlds naughty furnace burners and power stations and transport, and leave stuff that can be changed to fuel.). That is admirably logical, but I cannot shake off my emotional attachment to trees, and grasses, and crops, and teeming bio-diversity of pests and insects and little animals all presumably unfeasible in our brave new world of "let's grow our fuel"

 

[mheslep]

I know solar cells aren't a battery. I meant to ask which was more efficient at converting solar energy to a useable form (electricity/chemical), which you answered anyways. (Has an actual comparison been done though?)

Yes. Maximum possible efficiency of chemical energy capture via photosynthesis is 20-25%, I suspect Algae is the only player that can come anywhere close to that. Then note that energy is conveniently stored chemically until you need it, though when you do use the energy it will be via some heat engine and you will waste half at that time. Photovoltaic efficiency has been at ~12% for many years, and is just now commonly commercially available at 22%. Much more expensive (6 figures for a couple M^2) multi-band PVs such as the ones used on the Mars rovers pull >40%. And, there is research ongoing now using quantum dots that should achieve 60%. Solar is not 'stored', as has been stated many times here, unless its fed into a battery or other such device. However, if you do store the power in a battery you'll only waste 10-15% when using it later in a battery-electric motor system such as for a vehicle, vs 50% when burning fuel in a combustion engine.

 

[vanesch]

Yes. Maximum possible efficiency of chemical energy capture via photosynthesis is 20-25%, I suspect Algae is the only player that can come anywhere close to that.

I have no clue, but I'm amazed by that figure. So I googled a bit and I found this:
http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6VRV-4S9R4K5-2&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=d5765c1c54a03be6b821c39433029323

Abstract:

Photosynthesis is the source of our food and fiber. Increasing world population, economic development, and diminishing land resources forecast that a doubling of productivity is critical in meeting agricultural demand before the end of this century. A starting point for evaluating the global potential to meet this goal is establishing the maximum efficiency of photosynthetic solar energy conversion. The potential efficiency of each step of the photosynthetic process from light capture to carbohydrate synthesis is examined. This reveals the maximum conversion efficiency of solar energy to biomass is 4.6% for C3 photosynthesis at 30 °C and today's 380 ppm atmospheric [CO2], but 6% for C4 photosynthesis. This advantage over C3 will disappear as atmospheric [CO2] nears 700 ppm.

and:

http://www.fao.org/docrep/w7241e/w7241e05.htm#1.2.1 photosynthetic efficiency

The net result being an overall photosynthetic efficiency of between 3 and 6% of total solar radiation.

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)

 

[B. Elliott]

Hopefully I have explained my thinking in the post above. We don't have to have additional CO2 [beyond ambient] to grow algae, but it may help to get the industry started by making it more economical. Ultimately, if we can produce cost competitive fuels from algae using only ambient CO2, the fuel becomes carbon neutral - we only release into the atmosphere the carbon that was absorbed from it in order to grow the algae. So at that point we are not releasing any "new" CO2.

How much algae would be required, acreage-wise, to be a sufficient amount which could be used to produce power for cities and automobiles to drive off of? How quick is the return? ie; can the algae grow quick enough to maintain a steady supply considering the new found demand?

 

[vanesch]

That is admirably logical, but I cannot shake off my emotional attachment to trees, and grasses, and crops, and teeming bio-diversity of pests and insects and little animals all presumably unfeasible in our brave new world of "let's grow our fuel"

For sure I hope they will do this off-shore !

 

[NeoDevin]

So a solution to energy problems, through strictly solar power, could be to have PV, with an algae-oil backup. The oil is produced in relatively small quantities at all times, but only burned when the PV cannot keep up with demand. Combine this with spreading PV across large areas to minimize fluctuations (has the entirety of north america ever been completely cloud covered?) and it could be feasible.

So we don't need enough oil production to cover our entire energy needs at all times, just enough to cover the times when PV cannot keep up.

 

[vanesch]

So we don't need enough oil production to cover our entire energy needs at all times, just enough to cover the times when PV cannot keep up.

Which is more than half of the time: at night, and in winter, solar is way below average production.

This is the question I ask then: if you have in any case to foresee more than 50% of provision with another technology, why bother with PV ?

 

[GTrax]

100,000 tons of Algae!
Arrived in late May and covers 13,000 sq km.

Pictures can be had http://news.bbc.co.uk/1/hi/world/asia-pacific/7482791.stm"

On the news, it was said the algae growth was driven by "pollution". There are 10,000 Chinese put to dispose of this stuff in time for a sporting event. Thats lots of carbon locked up in 100,000 tons of plant that got there by doing its biology thing with sunlight over an impressive area of ocean!

For sure I hope they will do this off-shore !

We did not have to ask it to do this. It did not require technology investment, capital growth or shareholder payoff. No matter the efficiency of the medium does not match the best we put on a Mars rover, it makes up for it It by using 5000 sq miles. We could burn it, and feel smug about being carbon neutral, or ferment it and make something smelling much sweeter to run our cars on, or we can leave it out there to make its contribution to undoing our damage. Is anyone allowed to be "Carbon Non-Neutral" ?

EDIT: Sorry - the 100,000 tons was what had already been removed. It seems the total is much more!

 

[Ivan Seeking]

For sure I hope they will do this off-shore !

Yes, and when one factors in the number of Hs needed to make a fatty acid, the logic of using salt-water algae is apparent.

Consider for example one common unsaturated fatty acid found in algae oil, Linoleic acid:
CH3(CH2)4CH=CHCH2CH=CH(CH2)7COOH

This is one of the acids that is transesterified to make biodiesel.

In order for the alga to make each molecule of the fatty acid, we need, what, 32 hydrogens, so 16 water molecules.

I don't think this rules out land-based or fresh-water systems altogether as there as places that have plenty of water, but we certainly don't want algae competing with humans, livestock, and food farming, for clean water. So it seems that some land-based systems makes sense, but in the end, we want to use salt-water.

 

[Ivan Seeking]

100,000 tons of Algae!
Arrived in late May and covers 13,000 sq km.

Pictures can be had http://news.bbc.co.uk/1/hi/world/asia-pacific/7482791.stm"

On the news, it was said the algae growth was driven by "pollution". There are 10,000 Chinese put to dispose of this stuff in time for a sporting event. Thats lots of carbon locked up in 100,000 tons of plant that got there by doing its biology thing with sunlight over an impressive area of ocean!


We did not have to ask it to do this. It did not require technology investment, capital growth or shareholder payoff. No matter the efficiency of the medium does not match the best we put on a Mars rover, it makes up for it It by using 5000 sq miles. We could burn it, and feel smug about being carbon neutral, or ferment it and make something smelling much sweeter to run our cars on, or we can leave it out there to make its contribution to undoing our damage. Is anyone allowed to be "Carbon Non-Neutral" ?

EDIT: Sorry - the 100,000 tons was what had already been removed. It seems the total is much more!

We need to be careful about the energy spend to collect the algae, but yes, if we just burn the biomass we are way ahead of the game. Algae has been doing precisely what we need since long before we humans ever arrived on the scene with our campfires.

 

[Ivan Seeking]

In summary, if it takes you 10 years to switch everything (electricity + transport) to algae biofuel, then go ahead.

Clean and highly efficient diesel cars are already popular in Europe, and with the ultra-low sulfur fuels now required in the US, we can run diesel cars here. [note that biodiesel contains no sulfur]. In fact we are now seeing diesel pumps at most filling stations, which is new. We already have a large demand from the transportation industry for biodiesel, and even some of the more reserved claims by people working to solve specific problems with algae, are landing in the 5 years range. So it appears that everything is already in place. Meanwhile, some experts are predicting that crude will hit $200 by July, next year.

If it takes you 40-50 years, then I'd give preference to algae for transport, and nuclear for electricity, because otherwise we will still have 3 or 4 decades of coal ahead.

Forty years ago, when I was a kid, it was all but a foregone conclusion that by now we would have practical electric cars running on fusion power; and flying cars for that matter! But the point is that we can't count on any future technology to save us from the plight of oil. And even if we eventually see an electric battery that makes electric cars practical [we have no gaurantee that will EVER happen] we still don't know that it will ever be possible to fly planes and power trucks on electric power. The only other option for this would be to burn hydrogen produced using nuclear power, but this will not be possible for decades because we don't have the power or the infrastructure for hydrogen. However, jet aircraft have already been flown, and many commercial trucks are now running on biodiesel.

This is what I hadn't figured out.

Yes, I realized that I getting ahead of myself a bit and not mentioning critical details.

 

[Ivan Seeking]

Oh yes, but for closed systems - for power generation and not fuel production - we reclaim the water from the exhaust stream of the burning algae biomass, so in principle we don't need water beyond the initial charge of the system. We [in principle] have nothing but sunlight going in, and electric power coming out.

...So if we compare this to PV, I think it utimately comes down to the cost per square mile for solar cells, as opposed to the cost per square mile for algae bioreactors, the efficiencies, the maintenance costs, the lifespan, and the ability to recycle the components of the systems. As for cost, we see numbers ranging from ~ $2 to $200 per sq. foot for bioreactors.

 

[vanesch]

Clean and highly efficient diesel cars are already popular in Europe, and with the ultra-low sulfur fuels now required in the US, we can run diesel cars here. [note that biodiesel contains no sulfur]. In fact we are now seeing diesel pumps at most filling stations, which is new.

I wasn't talking about the distribution or the cars: that's one of the evident advantages of biodiesel, that it will require few if any modifications to the current way of using fuel for transport. (btw, I'm surprised: I have seen diesel pumps in filling stations, and diesel cars since I was a kid). This is THE big advantage of the biofuel approach. No, the time scale I was talking about was to set up such an amount of practical and economical production of biofuel that it can essentially replace about all oil consumption (which is indeed essentially for transport, and also for heating, which can also be done transparently), and that on top of that there is sufficient economical growth to start replacing electricity production on large scale. Because, promising as it may seem, I still want to see it done on such a large scale.

I was saying that if there is an "upper limit" on the practice of making biofuel for everything in 10-15 years time, and if the horizon of practical large scale electricity production by biofuel, after already having replaced mineral oil about everywhere, is more on the 40 years time scale, or if there are more fundamental problems to going to such large scales which put this to an undefined time horizon then it might still be useful to switch from coal to nuclear in the mean time.

Forty years ago, when I was a kid, it was all but a foregone conclusion that by now we would have practical electric cars running on fusion power; and flying cars for that matter! But the point is that we can't count on any future technology to save us from the plight of oil. And even if we eventually see an electric battery that makes electric cars practical [we have no gaurantee that will EVER happen] we still don't know that it will ever be possible to fly planes and power trucks on electric power. The only other option for this would be to burn hydrogen produced using nuclear power, but this will not be possible for decades because we don't have the power. However, jet aircraft have already been flown, and many commercial trucks are now running on biodiesel.

I agree. But again, let's see the speed and the growth potential: we're still talking about a technology in its infancy ; hopefully the biofuel will not be the new fusion power of 40 years ago, which didn't keep its promises. As I said, if we can go to this biofuel for transportation and other uses of oil, that would be great, but it is a challenge of scale. I'm absolutely not arguing for electric cars, it would be a major change and it also has a lot of technological challenges. The electric car, however, has had another problem, which might now be undone: the very cheap and reliable car on petrol. There was simply no market incentive. Expensive oil might change this. But if biofuel comes along, then that can solve the issue also.

I've always been against biofuels because I always saw them competing for the same resources as other human needs, like water and agriculture. I found this an extremely dangerous path to walk. But given that this problem isn't the case with this algae thing, I really like it. But again, one still has to show how it will work out on large scale. Nuclear is to me the proven technology that can help us out with electricity ; I don't think that there is much promise in the hyped PV or wind at this point, for which to me the main difficulty which remains unsolved is the intermittency - even apart from its price. Maybe biofuels can also be a competing technology for electricity production, and if in the near enough future they prove to be a better technology, then I'm all for it, and I'm willing to put nuclear aside. But first, replace oil already. We'll see after that. At least, biofuels don't seem to have a fundamental difficulty such as intermittency, and CAN be seen as a real solution to electricity production. I have to say it is the FIRST time I see another potentially realistic solution, apart from nuclear, to produce electricity without restriction, in large quantities, when demanded. It is time to stop harassing people to "economize" electricity: it should flow in large and cheap quantities. Nuclear can do that, and if bio fuel can do that, then it is the first worthy competitor of nuclear in that respect, which might win the competition. Future will tell. Maybe one should seriously rethink the current fashion for PV and wind turbines, which have in any case not the potential to bring a serious solution in the next decades.

 

[Ivan Seeking]

I wasn't talking about the distribution or the cars: that's one of the evident advantages of biodiesel, that it will require few if any modifications to the current way of using fuel for transport. (btw, I'm surprised: I have seen diesel pumps in filling stations, and diesel cars since I was a kid). This is THE big advantage of the biofuel approach. No, the time scale I was talking about was to set up such an amount of practical and economical production of biofuel that it can essentially replace about all oil consumption (which is indeed essentially for transport, and also for heating, which can also be done transparently), and that on top of that there is sufficient economical growth to start replacing electricity production on large scale. Because, promising as it may seem, I still want to see it done on such a large scale.

No doubt, until we see the application at scale, we can't know with absolute certainty that it can work; or really how long it will take to be competitive. Obviously I am greatly inclined to think it can be competitive soon if we are smart and practical about things, but there is one big difference between this and many failed options: The fuel is there. This is not a problem of fundamentals or energy density, it is merely a matter of solving practical problems. For this reason I stongly urge that this is where we should put our greatest efforts.

As for the motivation and the ability to do this quickly, I am counting on the over 1/2 trillion dollars that will be added to our economy annually by displacing foreign oil. If you want to get something done quickly, offer Americans lots of money.

Btw, my avatar is a picture of a couple of algae cells with the pockets of oil stained red.

I must go to bed now.

 

[Ivan Seeking]

Damn, okay, one more thing: If the Chinese would just burn all of that algae for steam powered generators, I think we would have our first crude example operation at scale, for power.

 

[Dale]

In return they hoped to get carbon credits.

No, in return they hoped to sell carbon credits.

By the way, I grabbed the newest popular science magazine because it had an interesting "eco-tropolis" story. It mentioned an interesting idea I had not considered. Use nuclear power and air to synthesize liquid fuels. No estimates on price per barrel where it would be competitive using existing technologies, but I thought it was an interesting idea.

Anyway, Ivan, what do you consider "the energy problem"? Are you principally concerned about the environmental or economic impact. I am personally more concerned about the economic impact, but I think that nuclear power helps on both fronts.

 

[Ivan Seeking]

No, in return they hoped to sell carbon credits.

You can't sell what you don't have.

By the way, I grabbed the newest popular science magazine because it had an interesting "eco-tropolis" story. It mentioned an interesting idea I had not considered. Use nuclear power and air to synthesize liquid fuels. No estimates on price per barrel where it would be competitive using existing technologies, but I thought it was an interesting idea.

Perhaps, but I have seen no evidence that this can be practical.

Anyway, Ivan, what do you consider "the energy problem"? Are you principally concerned about the environmental or economic impact. I am personally more concerned about the economic impact, but I think that nuclear power helps on both fronts.

I am concerned about the environment and the economy, but I am most concerned about the oil supply. Already the impact of the current price of crude ripples through, the economy, and through society generally - from the price of food to reduced air travel, from riots and protests globally to the closing of 600 Starbucks in the US. Not only is the supply of oil critical to our way of life, our standard of living also depends on the price of oil. Long before peak oil poses problems through shortages, the price of oil could not only change our lives forever, but it may well lead to global conflicts, as well as civil unrest.

The need for oil is far more dangerous than religious radicals because every country in the world needs oil.

Even going way back: The attack on Pearl Harbor was rooted in oil.

 

[Ivan Seeking]

I have to wince every time McCain et al tries to link nuclear power to the oil problem. It shows a fundamental lack of understanding of the problem.

 

[rewebster]

hey, Ivan---what's the biggest algae/oil project so far in the way of an ongoing production per day?

 

[Ivan Seeking]

I don't know. Almost all work being done is proprietary, and most people are working on specific aspects of production problems. It is fairly easy to produce mass quantities of algae, but the challenge is to develop economical and practical solutions for production at scale.

 

[rewebster]

well, they (we) need to find the best algae for oil production, a bacteria that feeds off of the dead algae that also produces oil (at night), another bacteria that feeds off of both of those that produces hydrogen, then a solar cell on the bottom of the algae/bacteria tank that uses the rest of the sunlight that the algae doesn't use.

did I miss anything?

(oh, yeah, it uses coal furnace gas, all of it is edible and safe to drink)

 

[mheslep]

I have to wince every time McCain et al tries to link nuclear power to the oil problem. It shows a fundamental lack of understanding of the problem.

In what sense? There's plenty of evidence that considerable oil usage can be displaced by electric power. Just a 10-20% reduction in US oil usage would relieve the price pressure.

 

[Ivan Seeking]

...we...

MIT is working on algae based hydrogen. So it would appear that algae allows us to not only solve the immediate problem, but also to take the next step to a hydrogen economy.

But you are correct in pointing out that algae may only be a part of the equation. There is promising work going on in many areas, including work with bacteria. Biocrude looks very promising.

 

[Ivan Seeking]

In what sense? There's plenty of evidence that considerable oil usage can be displaced by electric power.

How?

 

[rewebster]

OK--most (maybe) of the oil is from algae--------I wonder what percentage of coal is (may be) algae?

 

[Ivan Seeking]

Even if we ignore the projections for supply, we can see what happens to demand.

http://wwotext.blogspot.com/2007/05/world-oil-supply-and-demand-projections.html

 

[rewebster]

Even if we ignore the projections for supply, we can see what happens to demand.

http://wwotext.blogspot.com/2007/05/world-oil-supply-and-demand-projections.html

if that's even halfway close guess from 2005, and you look at 2008 (a shortfall already projected then) and the prices now at 2008---then look around 2012 to 15 for the 'shortfall' dropping off even more--I wonder what the price of oil is going to be then?

 

[Dale]

I am concerned about the environment and the economy, but I am most concerned about the oil supply. Already the impact of the current price of crude ripples through, the economy, and through society generally

Then you cannot ignore or dismiss nuclear power. The solution to the oil crisis is not dependency on another single fuel, but diversification of our transportation sector energy needs. We need to have fossil fuels, biofuels, nuclear, and other energy sources all competing with each other for at least a portion of the transportation sector. Even if each alternative technology is only a small niche and petroleum still dominates it will still greatly impact the marginal elasticity of demand.

 

[Ivan Seeking]

Then you cannot ignore or dismiss nuclear power. The solution to the oil crisis is not dependency on another single fuel, but diversification of our transportation sector energy needs. We need to have fossil fuels, biofuels, nuclear, and other energy sources all competing with each other for at least a portion of the transportation sector. Even if each alternative technology is only a small niche and petroleum still dominates it will still greatly impact the marginal elasticity of demand.

You are missing the essential point: We have no alternative to oil because we have no battery to make electric cars practical. I have been waiting for the promise of an effective battery, which has been just beyond the horizon, for forty years now. We have no more time to wait.

 

[Dale]

You are missing the essential point: We have no alternative to oil because we have no battery to make electric cars practical.

Sure we do. Plug-in hybrids already exist. Commuter transportation could be entirely serviced by electricity with existing battery technology.

I would encourage widespread adoption of existing flex-fuel and plug-in technology to diversify our energy options.