Energy Return on Investment

[free spirit]

Solar is, by all accounts, the most "competitive" renewable energy source in EROEI terms. A basket of renewable technologies will be less capable of powering the manufacturing system than solar alone. So if solar cannot theoretically power everything currently powered by hydrocarbon, right down to the container ships, nothing can.

aside from anything else, why've you suddenly started with this fallacy?

Solar is not generally seen as being the most competitive renewable energy source in EROEI terms - that would be hydro, followed probably by tidal, geothermal, tidal stream, largescale wind, then maybe solar.

I've never seen any analysis suggesting otherwise, though I suppose it will vary to some extent for different areas of the world, certainly if we're talking UK then the above would be about right on average.

 

[Falcon]

No more vague arm-waving, Falcon. you need to address fs's points, I think. If the eroei for solar is somewhere in the region of 8:1, then I would think it has a compelling case to be part of the future energy mix. Fuck, even if it's 3 or 4:1, it's probably still worth it.

I'm sorry - if we can't have an exploratory conversation about uncertainties without being accused of arm waiving, then a debating forum degrades to a mere exchange of statistics.

If I have misunderstood the intellectual basis of the conversation, then I apologise. I'm doing my best to have an "interesting" conversation with you.

 

[littlebabyjesus]

So there are already a fair few renewable sources with very good eroei ratios? Given that 8:1 is not bad.

 

[littlebabyjesus]

I'm sorry - if we can't have an exploratory conversation about uncertainties without being accused of arm waiving, then a debating forum degrades to an exchange of statistics.

If I have misunderstood the intellectual basis of the conversation, then I apologise. I'm doing my best to have an "interesting" conversation with you.

Do you accept that there is no great systems-failure-producing problem in principle with replacing 50:1 eroei fuel with an 8:1 one?

The efficiency of engines, machines and home insulation will be more important factors.

 

[free spirit]

Yes but your calculations are still based on the assumption that "something else" is doing all the heavy lifting to cause your renewable powered EV and its batteries to be there in the first place. They have appeared fully formed from under a gooseberry bush.

just as something else other than oil is powering all the electricity supplies around the world that power most of the manufacturing processes, factory lighting, heating etc etc?

Those thermal losses which make your example appear to favour renewable energy in the transport example are in fact typical losses in a large number of renewable energy manufacturing processes (e.g. ore smelting) which have to be overcome.

Sorry.

Yes, but that's already accounted for in the EROEI figures isn't it.

And for the renewable source it only occurs once in its lifecycle whereas for petrol / diesel engines it occurs constantly throughout it's operating life.

 

[free spirit]

So there are already a fair few renewable sources with very good eroei ratios? Given that 8:1 is not bad.

hydro is generally seen as something between 50:1 and 200:1, roughly similar for tidal though probably more like 50:1 as the higher numbers apply to the highest head hydro systems, wind's in the region of 20:1 etc.

 

[littlebabyjesus]

So really, eroei isn't an issue at all. The problems with increasing renewables lie elsewhere.

 

[Falcon]

Do you accept that there is no great systems-failure-producing problem in principle with replacing 50:1 eroei fuel with an 8:1 one?

I absolutely reject that there is no great systems-failure-producing problem in principle with replacing 50:1 eroei fuel with an 8:1 one. It is the central consistent explanatory factor for why every complex civilisation has failed. Again, to repeat previous postings.

Each civilisation exploits the highest EROEI fuel available to it to create the maximum amount of complexity consistent with that fuel (complexity is a function of EROEI). For example, we have exploited >50 EROEI fuel to create a complex industrial agricultural system that now supports 7 billion people.

That complexity of itself increases the fuel requirement of the civilisation.

When that fuel EROEI reduces, the civilisation finds itself with a level of complexity which cannot be sustained at that lower EROEI and undergoes a "reduction in complexity" (systems theory speak for "collapse").

Fuel is a specific instance of the general problem in ecosystems when the supply of the first rate-limiting resource is exhausted.

It's why an engineering calculation based approach to this is unsatisfactory - you really need a different conceptual model to understand the predicament.

 

[Falcon]

So really, eroei isn't an issue at all. The problems with increasing renewables lie elsewhere.

The problem is that all the 200:1 hydro capacity has already been exploited. There is certainly none at the capacity schedule demanded by a 10% per annum uninvested depletion rate in our primary energy supply.

 

[littlebabyjesus]

I'm going to have to flatly disagree with you there, then. It would require changes in priorities, but there's no problem there with the political will, and the roughly 10 percent added cost to the economy could easily be offset by efficiency savings. The relatively cheap availability of oil has also made us very wasteful in our consumption - cutting down on that waste would not be that hard. As fs said, it would probably actually improve most people's lives not to be so wasteful.

I'll leave others to comment on the potential shape of post-oil agriculture. I think fs linked to something a while back about the most productive farming in the world now being oil-free. There is a future for food production without oil. The means to produce high yields are already well understood.

 

[free spirit]

This is where I believe Free Spirit trips up, conceptually.

I think you, like him, are asserting that the proportion of energy of manufacturing and operating a container ship that should be allocated to solar should be in proportion to solar's share of global energy supply i.e. fractions of a percent.

But to my previous post: it is only worth allocating our fixed and small remaining stock of high EROEI fuel to building large scale renewable energy generating capacity if we believe that the manufacturing system can ultimately be powered by that renewable generating capacity. Otherwise it will fail, and our investment will be wasted.

why must renewable energy alone provide the power for everything by itself?

We will continue to have coal, oil, gas and nuclear available even if at much reduced levels for as long into the future as we realistically ought to be planning for, and if there are any vital aspects of the situation that can't be sensibly run from renewables, then they can remain powered from fossil fuels.

Renewables can and will provide the bulk of our energy requirements, fossil fuels can and will supply the balance of those requirements at reducing levels as renewables takes up the slack.

If we don't have those renewables, then we'll instead be entirely reliant on those reducing quantities of fossil fuels, so I really don't get why you would possibly favour that option.

 

[Falcon]

Yes, but that's already accounted for in the EROEI figures isn't it.

In what way? The EROEI figure describes the ratio of the energy yielded to the provisioning energy.

The losses are the losses occurring in the hundreds of energy conversion steps in the manufacturing process.

They are unrelated, aren't they?

The issue is that, when high EROEI fuel is driving the processes there is sufficient margin to meet the losses. The question is how those same losses can be met at low EROEI fuel.

 

[littlebabyjesus]

What is low eroei, though?

Serious point. I would think that 2:1 would be pretty low. 4:1 not so bad. 8:1 pretty good. 20:1 excellent. And anything above 20:1 is only a marginal improvement as 20:1 is already 95 percent.

But actually, you're wrong, I think. The eroei figure includes those things. It includes the energy cost of each manufacturing process involved.

 

[Falcon]

I'm going to have to flatly disagree with you there, then.

Well, you aren't disagreeing with me, you are disagreeing with everyone who has ever paid attention to this. There are no examples in recorded history of a complex civilisation surviving a reduction in EROEI of its primary energy supply without major collapse, and there has never been a civilisation as complex as ours.

As for fs's agriculture links, the task of getting high yields under ideal conditions on preselected land, and getting those results on land sterilised by 8 decades of industrial agricultural methods in a destabilising climate are different. But we digress.

 

[Bob_the_lost]

I've got a few thoughts, Falcon's position is that for an EROEI to be valid it must cover every single input that was required to support the industry and society that was required to build it. I have several thoughts around this logic.

In such a scenario, where we can accurately and precisely (not to be mistaken) calculate the total amount of energy that went into the manufacture of a Solar panel (or oil derrik), the EROEI needed for the pannel to be of net benefit would be anything larger than one. If it were matching the energy in with the energy it produces then it'd be of no use, if it used more than it provided then it would be a drain on the economy, if the ratio were over 1 then it would be of net benefit and would be all that is needed (or a selection of sources averaging a ratio of greater than 1, not all have to be)

Such a calculation would have a few challenges, how would you include the energy needed to advertise the mustard in the sandwich of the guy who heckled an elected official who once thought about putting an early day motion to ban wind turbines but chose not to as he was feeling a bit poorly that day?

Of course that's ridiculous, we'll never be able to calculate that accurately but demanding a perfect calculation and also demanding an EROEI of greater than 50 to be useful is clearly bollocks. To have any merit one should chose to pursue either a perfect calculation and one to one ratio, or an admission that the calculation cannot be accurate and to stop bitching about it and try to settle on a ratio that is valid.

Also the assumption that the panels must provide enough energy to contribute to things that pre-date them is pretty clearly bollocks. As too is the assumption that they must be capable of providing power for things that were built in the past. If steel and concrete become too expensive then tamped soil and wood can be used to mount panels. If roads use too much bitumen then dirt tracks will suffice. Whilst the attempt to quantise and enumerate all variables is futile that's not the worst thing about it, the base assumption that the system is static, that the values found must still have relevance is completely untested and frequently without merit.

 

[Falcon]

What is low eroei, though?

Serious point. I would think that 2:1 would be pretty low. 4:1 not so bad. 8:1 pretty good. 20:1 excellent. And anything above 20:1 is only a marginal improvement as 20:1 is already 95 percent.

See Hall "What is the Minimum EROI that a Sustainable Society Must Have?" (link) At 3 you have nothing you recognise as civilisation.

But actually, you're wrong, I think. The eroei figure includes those things. It includes the energy cost of each manufacturing process involved.

No - fs was using the thermal drop to his advantage to try to show renewables to be superior to thermal in motive applications, which is true. But thermal processes are inseparable to the manufacturing process and, fs's helpful link to the embodied energy of floor tiles notwithstanding, are not accounted for in EROEIs.

 

[free spirit]

I absolutely reject that there is no great systems-failure-producing problem in principle with replacing 50:1 eroei fuel with an 8:1 one. It is the central consistent explanatory factor for why every complex civilisation has failed

The vast majority of previous civilisations failed due to either being conquered by overwhelming military force, being near bankrupted by the costs of defending military attacks, daft religious / political reactions to problems, environmental changes, or in some cases overwhelming the carrying capacity of the surrounding land (which I suppose related to your EROEI point)... or some combination of the above.

Even if it was, then this doesn't prove anything about the current situation, as presumably that EROEI was related to distance of the fuel source from the civilisation, and would continue to fall until the civilisation collapsed.

That is not the situation here, the EROEI figure for renewables isn't going to continue to decrease, if anything it will get better over time due to efficiency gains in the manufacturing process, or further down the line, the much lower energy costs of recycling aluminium from the frames into new frames vs producing virgin aluminium.

 

[littlebabyjesus]

Can't you explain to me? Why is 98% sustainable but 90% not? (Difference between 50:1 and 10:1.)

As for your civilisation point, well every civilisation, however you want to define that, that preceded the current one failed, by definition. China can make a strong case for having had a continuous civilisation for 2000 years, mind you.

Examples such as Easter Island are not generalisable. What happened on Easter Island is what also happened on Tasmania. Where a small population is cut off from trade links with any other groups, which was the case on both of these islands, the society suffers from technological regression. We have the very opposite of that now, with exponentially greater opportunities for trade and the exchange of ideas than ever before.

 

[Falcon]

In such a scenario, where we can accurately and precisely (not to be mistaken) calculate the total amount of energy that went into the manufacture of a Solar panel (or oil derrik), the EROEI needed for the pannel to be of net benefit would be anything larger than one. If it were matching the energy in with the energy it produces then it'd be of no use, if it used more than it provided then it would be a drain on the economy, if the ratio were over 1 then it would be of net benefit and would be all that is needed (or a selection of sources averaging a ratio of greater than 1, not all have to be)

Unfortunately, the "as long as it's >1" argument fails to recognising the scaling problem.

An EROEI of 2 needs 25* times more resource inputs than an EROEI of 50 to satisfy the same total power output. The multiple approaches infinity as EROEI approaches 1. You quickly exceed the first rate limiting scarce resource in the manufacturing process. Actually, its the same problem going from oil to renewables - your resource demand for the same power demand escalates, in a system which is already saturating.

*I'm tired. Read "a much larger multiple"

 

[free spirit]

No - fs was using the thermal drop to his advantage to try to show renewables to be superior to thermal in motive applications, which is true.

thanks for at least accepting that point, I was beginning to despair for you.

But thermal processes are inseparable to the manufacturing process and, fs's helpful link to the embodied energy of floor tiles notwithstanding, are not accounted for in EROEIs.

Of course they are. How could you possibly think that an EROEI calculation for solar (for example) wouldn't incorporate the thermal processes involved in the manufacturing process.

As I've just pointed out though, the difference is that this is a one time only energy cost for the solar panels, vs the thermal losses in an ICE occurring continuously throughout it's operating life every time it's used.

 

[Bob_the_lost]

Unfortunately, the "as long as it's >1" argument fails to recognising the scaling problem.

An EROEI of 2 needs 25* times more resource inputs than an EROEI of 50 to satisfy the same total power output. The multiple approaches infinity as EROEI approaches 1. You quickly exceed the first rate limiting scarce resource in the manufacturing process. Actually, its the same problem going from oil to renewables - your resource demand for the same power demand escalates, in a system which is already saturating.

*I'm tired. Read "a much larger multiple"

You may well be tired because your post is, to be uncharacteristic blunt, gibberish.

 

[Falcon]

The vast majority of previous civilisations failed due to either being conquered by overwhelming military force, being near bankrupted by the costs of defending military attacks, daft religious / political reactions to problems, environmental changes, or in some cases overwhelming the carrying capacity of the surrounding land (which I suppose related to your EROEI point)... or some combination of the above.

True. And totally compatible with my statement. Which I restate. No complex civilisation has ever survived a major reduction in the EROEI of its primary energy source. There are many other reasons why other complex civilisations have also failed, for which I think you for enumerating.

 

[free spirit]

In what way? The EROEI figure describes the ratio of the energy yielded to the provisioning energy.

The losses are the losses occurring in the hundreds of energy conversion steps in the manufacturing process.

They are unrelated, aren't they?

seriously?

No they are not unrelated. The energy input calculation includes all the energy inputs into the manufacturing process including the losses.

How could it be any other way?

 

[littlebabyjesus]

seriously?

No they are not unrelated. The energy input calculation includes all the energy inputs into the manufacturing process including the losses.

How could it be any other way?

That's what I assumed, too. It would be pretty meaningless otherwise.

 

[free spirit]

True. And totally compatible with my statement. Which I restate. No complex civilisation has ever survived a major reduction in the EROEI of its primary energy source. There are many other reasons why other complex civilisations have also failed, for which I think you for enumerating.

well that's an entirely different statement, but I'll not labour the point.

 

[Falcon]

No they are not unrelated. The energy input calculation includes all the energy inputs into the manufacturing process including the losses.

Which, as we've established, have captured the losses in the floor tiles pretty snappily, but are a little hazy in the matter of, say, ocean going container ships.

OK, boys and girls, since even basic ratios are now eluding our powers of cogitation, I shall bid you good night.

 

[littlebabyjesus]

No complex civilisation has ever survived a major reduction in the EROEI of its primary energy source.

Which specific failed complex societies did you have in mind as effective analogies/warnings for today?

Sorry, Falcon, but you're falling back on your bad habit of overblown, empty rhetoric again.

 

[free spirit]

That's what I assumed, too. It would be pretty meaningless otherwise.

indeed.

 

[free spirit]

Which, as we've established, have captured the losses in the floor tiles pretty snappily, but are a little hazy in the matter of, say, ocean going container ships.

OK, boys and girls, since even basic ratios are now eluding our powers of cogitation, I shall bid you good night.

oh no, come up, you made a specific statement which demonstrated a total lack of understanding of how EROEI calcs are carried out, at least have the decency to accept you were wrong on that statement, rather than throwing up a load of flack to attempt to cover your tracks.

Those thermal losses which make your example appear to favour renewable energy in the transport example are in fact typical losses in a large number of renewable energy manufacturing processes (e.g. ore smelting) which renewable sources now have to overcome.

In what way? The EROEI figure describes the ratio of the energy yielded to the provisioning energy.

The losses are the losses occurring in the hundreds of energy conversion steps in the manufacturing process.

They are unrelated, aren't they?

You were flat wrong to state that these losses aren't included in the EROEI figures.

And if you're flat wrong on that, then your rationale for dismissing my previous calculations of the relative well to wheels efficiency is rebutted, and my point stands.

 

[Falcon]

You may well be tired because your post is, to be uncharacteristic blunt, gibberish.

Can't resist. Just work out for the chaps what the resource demand of an EROEI source of 1.0 is to meet a net power out of 1 Watt, would you?

Night all.