Open Systems

[Pirate88179]

Tinman:

In your example...5 watts into light bulb and 5 watts out in both heat and light...so far so good.  Then you add a solar panel and want to count the electrical energy out of that panel claiming 0 input...is this correct? 

If so, what I think is wrong here is that you are counting the 5 watts out in both heat and LIGHT output from the bulb.  If some of that light is absorbed by the solar panel, and converted to electrical energy, then...by definition, you have "lost" some of the light output from the bulb.  This loss would then be considered input to the the panel.  I also think the panel would heat up a little thereby using more of your output from the bulb that you are not accounting for.  That energy from the bulb (both heat and light) is going into the panel and therefore, you can't just say it is still there as it was before you added that panel.  Some of that energy is now powering that solar panel and should be, must be, accounted for.

I could be wrong but, I don't think so.

Bill

[MarkE]

Lol,sounds like your boundaries are a mythical creature that you have invented. What you mean to say is-->we will continue to shift the goal post until such time that we make sure your device dose not exibit any sort of excess energy.

Pray tell what goal post has been moved?  You complained that the notion of a system boundary did not make sense to you and I have as others before me have offered you an explanation.

This boundary you speak off would be between the two(loosly coupled) systems,as you call it. This boundary would also be between the one system that has no effect on the other,regardless of wether it's there in opperation or not(which also is the same boundary as the first).

A boudnary is something that we draw for accounting reasons.  You can draw the boundaries where you like.  But once you do, the accounting rules are set.  Those who do not aspire to reincarnate Enron do not get to add what crosses from outside a boundary to inside it along with what comes from inside the boundary to the outside using the same sign for each.

If you disagree with that Mark,then place your boundary,and explain as to why it's there in that position. If you cannot,then please refrain from continually stating that I have the problem with accounting for energy.
This boundary would be around system one as a whole-->the battery,conecting wires and globe is system one.This system is running at 100% efficiency when all energy in and out is accounted for.

You have demonstrated double counting several times now.  I leave it to you to define the boundaries anywhere you like.  Once you do then we can all perform the accounting and contrast and compare.

Well whats the chances of that--> an accord

So there you have your boundaries Mark.
Boundary 1-is around system one. This system is running at 100% efficiency,where the energy in = the energy out. Net gain is 0.

Boundary 2-is around system 2(the solar panel,conecting wires and 100 ohm resistor)This boundary was set due to the fact that this system has no effect on system 1,regardless of wether it's there or not. This system is open to system one,and thus a sepperate boundary must be set around this system-->but im sure you would disagree with this!some how!

So, you have a light bulb:  energy goes in and the same energy goes out.  No excess.  And you have a solar panel connected to a resistor.  Again: the same amount of energy goes in as goes out.  Where is your excess?  Where is your anomaly?  Next we come to your pressure vessel:  Energy that goes out takes from what is inside.  Ditto your ram.  Ditto the combination.

[LibreEnergia]

...Lol,sounds like your boundaries are a mythical creature that you have invented...

Of course they are and that is the whole point. They are boundaries of (usually) arbitrary dimensions and idealized thermodynamic properties that may not actually exist in nature but are chosen to represent the theoretical limits that any real system approaches but could never exceed.

Consider for instance the concept of the DALR or "dry adiabatic lapse rate". It is a very important concept in determining the stability of the atmosphere. It represents the theoretical rate that a parcel of dry air will cool at as it rises in altitude. As such it utilizes the concept of a closed thermodynamic system (in this case an adiabatic one) on an arbitrary parcel of air.

I use analysis based on the DALR it all the time by reading a Skew T Log P plot to determine if I should drive to the local sailplane airfield and try and set forth on a cross country flight. The predictions it provides by comparing the actual temperate plot with altitude compared with the behaviour of the fictional 'air parcel' provides a very accurate way of predicting what the days flying will be like.

Incidentally thermals do cool as they rise. They also expand (doing work) as they rise. If they didn't as per your faulty analysis I may have never bothered to come home. I'd still be up in the sky enjoying myself circuiting the earth effortlessly.

That theoretical tool is just one example of an analysis based on a 'mythical creature' but there are hundreds more.

[tinman]

Tinman:

In your example...5 watts into light bulb and 5 watts out in both heat and light...so far so good.  Then you add a solar panel and want to count the electrical energy out of that panel claiming 0 input...is this correct? 

If so, what I think is wrong here is that you are counting the 5 watts out in both heat and LIGHT output from the bulb.  If some of that light is absorbed by the solar panel, and converted to electrical energy, then...by definition, you have "lost" some of the light output from the bulb.  This loss would then be considered input to the the panel.  I also think the panel would heat up a little thereby using more of your output from the bulb that you are not accounting for.  That energy from the bulb (both heat and light) is going into the panel and therefore, you can't just say it is still there as it was before you added that panel.  Some of that energy is now powering that solar panel and should be, must be, accounted for.

I could be wrong but, I don't think so.

Bill

Hi Bill

I know what your saying,but think of it this way. The light bulb will emmit x amount of lumens of light regardless of wether the solar panel is there or not.The lumen output of the bulb will not change from the solar panel being open circuit,or has a load placed across it's output-->0 reflection shown from the solar panel in either case. The heat output is radiant,and that also dose not change regardless of the solar panel and its load. No matter how you look at it,the solar panel changes nothing in regards to the heat and light output of the bulb.The solar panel also will not show any reflection on the P/in to the light bulb.

Lets calculate and messure this system as we would any other.
First P/in-->this being a DC system is easy-->volts x amps.This is our energy consumption.
Then calculate the energy output from the bulb. Heat and light. This is also easy,as it is equal to the energy in-->energy can be neither created nor destroyed-only transformed.We also must take into account the heat from the conecting wires and battery it self. As this will be a radiant heat,then it is an energy output.
So we have accounted for all our energy in and out,and have a net result of 0.

Now system two-->our solar panel and resistive load(100 ohms in this case). This is also a DC output,so easy to calculate.

So now,we do as we always do. We place the load on the solar panel,and then remeassure the energy output from system 1. Do you think it will change when the solar panel(system 2)has a load across it? If system 1 shows no change when system 2 is put into opperation,then system 2 is generating excess energy,as the energy in system 1 has been accounted for in the way of heat and light.

So in summery
System 2 dosnt change the heat output of system 1
System 2 dosnt change the light output of system 1
And system 2 dosnt reflect on the P/in of system 1

If the solar panel was open(no load across it) then it would be said that it isnt consuming any energy,as energy cannot be destroyed.If nothing is comming out,then nothing is going in. So all you have to do now Bill,is place a load across that solar panel,and show me any change in either the energy in(watts) to system 1,or the energy out of system 1,and i'll believe what you say

Whats happening here is a case of-->it's to simple to be true.
But if we had a transformer where the secondary shows no reflection on the primary what so ever,then every one would be jumping for joy. All we have here is that transformer,where light is converted into electrical energy,but shows no reflection on the primary.

MarkE will throw all sorts of curve balls at you(eg.boundaries)but never put together a system like this,and show that you are wrong-->he deals only in words and never in actual experimental setups as we do. So my challenge to him(and all here),show me a change in energy output or energy input in this system-on system 1,when system 2(the solar panel and resistive load)has a load placed on it.

Only words will follow,and very few experimental setups to see actual results.

[MarkE]

Hi Bill

I know what your saying,but think of it this way. The light bulb will emmit x amount of lumens of light regardless of wether the solar panel is there or not.The lumen output of the bulb will not change from the solar panel being open circuit,or has a load placed across it's output-->0 reflection shown from the solar panel in either case. The heat output is radiant,and that also dose not change regardless of the solar panel and its load. No matter how you look at it,the solar panel changes nothing in regards to the heat and light output of the bulb.The solar panel also will not show any reflection on the P/in to the light bulb.

That's not entirely true, but it is close enough not to quibble.

Lets calculate and messure this system as we would any other.
First P/in-->this being a DC system is easy-->volts x amps.This is our energy consumption.
Then calculate the energy output from the bulb. Heat and light. This is also easy,as it is equal to the energy in-->energy can be neither created nor destroyed-only transformed.We also must take into account the heat from the conecting wires and battery it self. As this will be a radiant heat,then it is an energy output.
So we have accounted for all our energy in and out,and have a net result of 0.

That is one isolated system and you have settled your balance.

Now system two-->our solar panel and resistive load(100 ohms in this case). This is also a DC output,so easy to calculate.

Note that the solar panel does not drive the resistor, and the resistor does not generate heat unless you supply energy to solar panel.  So you have a couple of choices:  Draw a boundary around the solar panel, or the solar panel and the resistor and E_IN = E_OUT + delta E_STORE for either of those systems.  Or draw a boundary that includes the light bulb, and now the light that hits the solar panel from the light bulb does not leave the interior, being absorbed instead by the solar panel, and guess what?  E_IN = E_OUT + delta E_STORE for the newly defined system.

So now,we do as we always do. We place the load on the solar panel,and then remeassure the energy output from system 1. Do you think it will change when the solar panel(system 2)has a load across it? If system 1 shows no change when system 2 is put into opperation,then system 2 is generating excess energy,as the energy in system 1 has been accounted for in the way of heat and light.

So in summery
System 2 dosnt change the heat output of system 1
System 2 dosnt change the light output of system 1
And system 2 dosnt reflect on the P/in of system 1

No, but it changes the available heat and light output of any system that includes System 1 and System 2.  Surely you are not so naive as to believe that we could put another solar panel behind the first one and it would intercept the same light as the first. 

If the solar panel was open(no load across it) then it would be said that it isnt consuming any energy,as energy cannot be destroyed.If nothing is comming out,then nothing is going in. So all you have to do now Bill,is place a load across that solar panel,and show me any change in either the energy in(watts) to system 1,or the energy out of system 1,and i'll believe what you say

When solar panels don't have loads across them, the intinsic photo diodes convert the electricity to heat.  Those photodiodes are what set the PV panel's open circuit voltage.

Whats happening here is a case of-->it's to simple to be true.
But if we had a transformer where the secondary shows no reflection on the primary what so ever,then every one would be jumping for joy. All we have here is that transformer,where light is converted into electrical energy,but shows no reflection on the primary.

First, there is a reflection, but it is so small that for all practical purposes we neglect it.  Second, the more you decouple an energy source from its load, the less source energy reaches the load, IE if you count efficiency as output of the load divided by the energy of the input, the efficiency is very poor.  That is for example what happens with Bill Alek's SFT transformer.  In the case of the solar panel, the light converts a fraction of the input electricity to light in the wavelength range that the solar panel responds to.  Then the solar panel covers only a small solid angle from the light. Then the solar panel has its own limited efficiency.  By the time you are done only a tiny fraction of the energy supplied to the light comes out of the solar panel as electricity.

MarkE will throw all sorts of curve balls at you(eg.boundaries)but never put together a system like this,and show that you are wrong-->he deals only in words and never in actual experimental setups as we do. So my challenge to him(and all here),show me a change in energy output or energy input in this system-on system 1,when system 2(the solar panel and resistive load)has a load placed on it.

Only words will follow,and very few experimental setups to see actual results.

There is really no need to build such a silly experiment because it is blindingly obvious that there is no surplus energy to be had powering a light and directing that light at a PV module.  Below is a diagram that shows just some possible boundaries that can be drawn around elements of this:  battery, light, PV panel, resistor combination.  No matter what combination of the four elements including all or none that one draws, when one accounts for all energy entering the interior through the boundary, and all energy exiting to the outside through the boundary:  E_IN - E_OUT = delta E_STORED.