[shortonsense]

Here he denies the validity of EROEI..

http://www.forbes.com/forbes/2005/1031/122.html (Thermodynamics and Money)

He sure seems positive on the future of energy.

Anyone with a functioning calculator can deny the validity of EROEI, the Qatari's do it so well they fly airplanes on <1 EROEI fuels.

http://www.reuters.com/article/idUSTRE59C1NJ20091013

The entire concept this guy puts forward, that the use of more diffuse energy to create concentrated energy in the necessary form, and our ability to do this better and better being critical to our future, strikes me as pretty well thought out compared to, "Gee, we've only got a few centuries of fossil fuels left, and as soon as we use half of it our only option is to dieoff".

[zeke3000]

Here he denies the validity of EROEI..

http://www.forbes.com/forbes/2005/1031/122.html (Thermodynamics and Money)

He sure seems positive on the future of energy.

Anyone with a functioning calculator can deny the validity of EROEI, the Qatari's do it so well they fly airplanes on <1 EROEI fuels.

http://www.reuters.com/article/idUSTRE59C1NJ20091013

The entire concept this guy puts forward, that the use of more diffuse energy to create concentrated energy in the necessary form, and our ability to do this better and better being critical to our future, strikes me as pretty well thought out compared to, "Gee, we've only got a few centuries of fossil fuels left, and as soon as we use half of it our only option is to dieoff".

I thought you can´t create energy.

[shortonsense]

I thought you can´t create energy.

You don't. The Virtue of Waste simply says you use a diffuse source of some sort, and using a process with an EROEI < 1 , you convert it into a more useful form with an appropriate net energy loss.

Think...solar power ( diffuse ) concentrated with mirrors to heat sodium.



Presto...an EROEI<1 and 500 megawatts peak generation.

[zeke3000]

I thought you can´t create energy.

You don't. The Virtue of Waste simply says you use a diffuse source of some sort, and using a process with an EROEI < 1 , you convert it into a more useful form with an appropriate net energy loss.

Think...solar power ( diffuse ) concentrated with mirrors to heat sodium.


Presto...an EROEI<1 and 500 megawatts peak generation.

So basically our (=the world´s) subsitute for oil is a "diffuse source of some sort" ? Well, that´s easy to agree with. The problem comes when you have to define what this "diffuse" is.

[shortonsense]

Think...solar power ( diffuse ) concentrated with mirrors to heat sodium.


Presto...an EROEI<1 and 500 megawatts peak generation.

So basically our (=the world´s) subsitute for oil is a "diffuse source of some sort" ? Well, that´s easy to agree with. The problem comes when you have to define what this "diffuse" is.

1000 w/m^2/hr hitting the planet at lunchtime strikes me as pretty diffuse. Probably not even enough to cause skin cancer if applied regularly. Concentrated however...it generates 500 megawatts of electricity.

Some might argue that diffuse is synonymous with poor EROEI. That might be reasonable as well.

Hubberts estimates of radioactive decay material available within black shales in the US would be another type of diffuse, collecting them to power the country for thousands of years was his concept. Good enough for Hubbert, good enough for Peakers! I always say.

[VMarcHart]

After you have used that energy (heat) to run your power plant, how do you retrieve it?

Some of it in electric power, some of it in heat --which can be reused for more electric power, chemical applications, etc--, and then in stuff you absorb but can't really do anything useful with it, like noise, smells, vibrations, air discharges, etc.

[culicomorpha]

I thought you can´t create energy.

You don't. The Virtue of Waste simply says you use a diffuse source of some sort, and using a process with an EROEI < 1 , you convert it into a more useful form with an appropriate net energy loss.

Think...solar power ( diffuse ) concentrated with mirrors to heat sodium.

Presto...an EROEI<1 and 500 megawatts peak generation.

Jeeze. This is not EROEI. You need a class in physics shortonsense. No wonder you cornies think the party will never end.

First off, energy is not measured in watts. Watts is a unit of power, or energy per unit time. Watt-hours is a unit of energy.

So to calculate the energy returned, you need to multiply the rate (in Megawatts) times the amount of time the power is generated. If the lifetime of the array is 30 years, and if the sun shines half of the day on average, then the total time it produces energy is roughly 130,000 hours. The total energy produced by the array is then: 500MW*130,000 hours =65.7GWh

Now I don't know how much energy it takes to make the array, but I would be willing to bet my life it is a lot less than 65.7GWh. That is to say, the EROEI is absolutely > 1

The article you reference is complete hogwash. He actually has it all backwards. When he talks about "order" being created from "wasting" energy, he is really referring to negentropy - the opposite of entropy, which is accomplished by one and only one thing in the known universe: life. We are the ones doing the ordering, and we are using energy to do so. That array did not materialize on its own. We made it.

And if you look at life, you see efficiencies so beyond our technological capabilities that it just boggles the imagination. I was just watching the 11th hour, and there was an example given of the Orb spider, which produces a filament stronger than steel at room temperature (i.e. at a very low energy). Nature cannot afford to waste energy, and I think in time, the human species will come to recognize that it cannot either.

[shortonsense]

Now I don't know how much energy it takes to make the array, but I would be willing to bet my life it is a lot less than 65.7GWh. That is to say, the EROEI is absolutely > 1

Really? I would say you have done a fantastic calculation, blazing through your calculation with the efficiency of undoubtedly a fine engineering background and years of experience.

Except....I didn't see the calculation for the actual feedstock of energy going into this system....why not?

Certainly I did consider the input energy.....it is, after all, required to make the 500 megawatts I referred to. I have no objection to megawatt hours, I was abbreviating for my own sake, but I tend to be literal, so if others catch me out for not being specific I say hats off to them. So hats off to you.

To create the 65.7 GW/h you calculated we need to consider the energy input and some rough estimate of efficiency, as well as what you focused on, which was simply building the array. Ignoring the array ( it being a minor part of the system ) I simply considered all relevant energy input, rather than counting only a small one such as the array. After all, while our local solar furnance might provide quite a bit of free energy, its contribution is still required to make nearly everything on this planet work properly.

Assuming we are operating at 20% efficiency ( sunlight to on site power, and yes, we can argue specifics but I don't believe such precision is required based on the engineering obviousness of the argument I am making ), the energy input to create the 65.7 GW/h ( can we just call it 1.21 JIGGA WATTS!! in our best Chrisopher Lloyd voice? ) would be on the order of 328.5 GW/h, so the real question is, how in the world was such an AWFUL system ever invented, considering the horrible nature of the EROEI? If it had been a peaker which invented this, they would never have filed with the patent office, the idea being so hideous!

[culicomorpha]

Now I don't know how much energy it takes to make the array, but I would be willing to bet my life it is a lot less than 65.7GWh. That is to say, the EROEI is absolutely > 1

Really? I would say you have done a fantastic calculation, blazing through your calculation with the efficiency of undoubtedly a fine engineering background and years of experience.

Except....I didn't see the calculation for the actual feedstock of energy going into this system....why not?

Certainly I did consider the input energy.....it is, after all, required to make the 500 megawatts I referred to. I have no objection to megawatt hours, I was abbreviating for my own sake, but I tend to be literal, so if others catch me out for not being specific I say hats off to them. So hats off to you.

To create the 65.7 GW/h you calculated we need to consider the energy input and some rough estimate of efficiency, as well as what you focused on, which was simply building the array. Ignoring the array ( it being a minor part of the system ) I simply considered all relevant energy input, rather than counting only a small one such as the array. After all, while our local solar furnance might provide quite a bit of free energy, its contribution is still required to make nearly everything on this planet work properly.

Assuming we are operating at 20% efficiency ( sunlight to on site power, and yes, we can argue specifics but I don't believe such precision is required based on the engineering obviousness of the argument I am making ), the energy input to create the 65.7 GW/h ( can we just call it 1.21 JIGGA WATTS!! in our best Chrisopher Lloyd voice? ) would be on the order of 328.5 GW/h, so the real question is, how in the world was such an AWFUL system ever invented, considering the horrible nature of the EROEI? If it had been a peaker which invented this, they would never have filed with the patent office, the idea being so hideous!

Oh, for goodness sakes.

I’ll clarify this for the sake of other people reading this forum, but you so misunderstand energy and power concepts that I would strongly suggest that other readers either check shortonsense’s math themselves or ask someone else who does know how to do these calculations.

OK, EROEI is energy returned (or output produced - in this case, by the Sun) divided by the energy input (or the energy required to build the array. Mathematically speaking,: EROEI = Eout/Ein

Output energy, as I calculated above, is around 65GWh, and this figure already includes the efficiency of the array.

Input energy required to produce the array includes mining all the materials: glass, silver for the mirrors, copper for the plumbing, etc etc. All these inputs require energy in mining, transportation, manufacturing, and in assembly and maintenance (human energy - i.e. food). And that food has energy inputs as well, so from a practical matter, it is quite complicated to actually determine the true energy cost of producing the array.

Let’s be exceedingly generous, and say that we used 1GWh to produce the array. That’s a SWAG, but my intuition is that this is a very high figure. This is roughly equivalent to the annual electric consumption for 70 million US homes, based on average household electric consumption for 2007, as reported by the EIA

Now that we have estimates for the output energy and the input energy, we can calculate the EROEI:

EROEI = Eout/Ein = 65.7GWh/1GWh = 65.7

This is obviously greater than 1.

FWIW, I would strongly suggest you pay more attention to your dimensional units. Concepts of power and energy are easy to confuse, and if you get sloppy with your units, you can make silly mistakes – as you did above.
Confusion of watts, watt-hours, and watts per hour

Terms such as watts per hour are often misused.[8] Watts per hour properly refers to the change of power per hour. Watts per hour (W/h) might be useful to characterize the ramp-up behavior of power plants. For example, a power plant that reaches a power output of 1 MW from 0 MW in 15 minutes has a ramp-up rate of 4 MW/h.

[culicomorpha]

I don't understand the "virtue" part. Can someone explain how the author is attempted to support his thesis : "This much is certain: It is by throwing energy overboard that we maintain and increase the order of our existence.". I just don't see any evidence for this statement whatsoever.

Your intuition serves you well Narz.

This is standard double-speak. Up is down, left is right, good is bad. It is insidious because the author invokes concepts that most people are not familiar with (the second law of thermodynamics), completely misapplies it to support his belief system, and then people like shortonsense put it out there as a "fascinating" idea. The idea is to make you feel good about using (and wasting) lots of energy.

I will give you three guesses as to who benefits when you use more energy to do a given task. There is an agenda here.

[shortonsense]

OK, EROEI is energy returned (or output produced - in this case, by the Sun) divided by the energy input (or the energy required to build the array. Mathematically speaking,: EROEI = Eout/Ein

Output energy, as I calculated above, is around 65GWh, and this figure already includes the efficiency of the array.

It includes the efficiency of the array on the downstream side after the loss...it does not consider the input energy prior to the efficiency loss.

Why not? You don't get your 1.21 JIGGAWATTS ( ) without it....and yet....you pretend it isn't required and only consider the energy required to build the array?