Comparing Energy Efficiency of New vs Recycled Paper

[soonsoon88]

How i am going to compare energy efficiency between new paper and recycle paper ?
in order to compare them, i have to convert all the energy require in those process into the same unit right ?
By using Joule ? or ?

 

[Zryn]

Joule is the unit of energy (kilojoule = 1000 joules, megajoule = 1000 kilojoules etc), and to compare the energy between processes, converting each process to similar units sounds good.

When comparing these processes however, be wary of different time periods (J/s compared to MJ/year), keep in mind costs like transport (how big a truck/ship, and how far to travel), think about the entire time line of the process (does the energy to grow / harvest / transport trees factor in) and figure out early on what is relevant and what is not (discuss the scope of the problem with people for different viewpoints)!

 

[soonsoon88]

Joule is the unit of energy (kilojoule = 1000 joules, megajoule = 1000 kilojoules etc), and to compare the energy between processes, converting each process to similar units sounds good.

When comparing these processes however, be wary of different time periods (J/s compared to MJ/year), keep in mind costs like transport (how big a truck/ship, and how far to travel), think about the entire time line of the process (does the energy to grow / harvest / transport trees factor in) and figure out early on what is relevant and what is not (discuss the scope of the problem with people for different viewpoints)!

Cost did cross my mind but since my topic is compare energy efficiency. is it ok for me to involve cost during comparison?
Take an example,
If all the cost involved in delivery for making new paper is higher than recycled paper.
Besides knowing cost value,what does it mean for me to relate energy efficiency ?

 

[Phrak]

Don't forget the energy overhead of employees who drive to work, and the energy overhead of public functionaries who monitor so called ecology friendly government kickbacks.

 

[Zryn]

If it takes $100 worth of diesal (?? MJoules/litre; I can't remember the value) to fill a truck with a 50 litre capacity tank and a 15% efficient engine which can carry 10tonne of new paper per delivery and the driver can drive back and forth 3 times between the paper manufacturer and the wholesaler, then you can figure out how much energy it costs to send each tonne of paper, as you will end up with joules/tonne. Do the same for the other modes of transport and you have your cost in energy instead of dollars.

The question is, do you want Joules/sheet of paper, Joules/ream of paper (500 sheets) or perhaps Joules/tonne of paper?

 

[soonsoon88]

If it takes $100 worth of diesal (?? MJoules/litre; I can't remember the value) to fill a truck with a 50 litre capacity tank and a 15% efficient engine which can carry 10tonne of new paper per delivery and the driver can drive back and forth 3 times between the paper manufacturer and the wholesaler, then you can figure out how much energy it costs to send each tonne of paper, as you will end up with joules/tonne. Do the same for the other modes of transport and you have your cost in energy instead of dollars.

The question is, do you want Joules/sheet of paper, Joules/ream of paper (500 sheets) or perhaps Joules/tonne of paper?

OKOK ! Thx ! i got what u mean !
May i ask for future ?
Besides collection data from different both factory..
Is it just do normal comparison..
am i need any simulation ??

 

[Zryn]

Depends on how much work you want to put in. Collection of data is good, but what happens if you make a mistake somewhere and don't see it?

The result of a simulation would strengthen your collection data results if they agree, or show you if you made a mistake somewhere if they disagreed. Useful either way, but perhaps time consuming.