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# how can I calculate Embodied-Energy or life-cycle by EnergyPlus?

I am working on my thesis which is based on EnergyPlus. I learned EnergyPlus and now can use this, but now I have to calculate the embodied energy and I don't know how to do this.

How can I calculate embodied energy using EnergyPlus?

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You can't calculate embodied energy directly from EnergyPlus. It would be something I'd really like to see though.

DesignBuilder has an output for embodied carbon (link). While it doesn't calculate embodied energy the CSV file gives weights (or areas) of each material which you can use along with the ICE database (spreadsheet) or other source on embodied energy data to calculate the embodied energy.

Alternatively you'll need to find the areas and thicknesses of all the materials in your building, then use the density to find the weight of each of them before calculating the embodied energy from that.

Depending on what you're actually modelling it may be simpler than that. If you're just considering the difference between a couple of insulation options then you need only consider the marginal embodied energy (this would be called a change-based embodied energy analysis). That is to say the difference between the options that you want to consider. For example if you're comparing two walls, one with no insulation and one with 50mm of insulated dry-lining, then you only need to consider the additional materials in the dry-lining boards (paper, plaster, insulation, possibly foil). All the rest of the building is the same in both scenarios so can be ignored.

What EnergyPlus is good for is the other side of the life cycle energy analysis - the operational energy, which is almost always greater than the embodied energy. Again, in a marginal energy analysis you only need to consider the difference in energy use in your two cases.

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I think this would be a good addition and just added a new "feedback" topic to the development team at:

https://energyplus.uservoice.com/foru...

If you think it would be a good addition, please vote for it.

( 2016-04-11 14:43:34 -0500 )edit
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Another hack, if you don't care about monetary cost is take over the lifecycle cost objects; instead of representing dollars, interpret it as an energy unit or weight of carbon. This would allow you to make use of expected life and O and M impacts, not just for constructions, but also large pieces of equipment. You could even look at impact of how occupants get to the facility.

( 2016-04-11 15:49:39 -0500 )edit

That's a good idea for a rough approximation (probably good enough given the other uncertainties), but the problem I found is that you can't account for dependencies between components in a construction.

( 2016-04-11 16:49:33 -0500 )edit

I believe IES-VE can do IMPACT calculations. Another alternative to the spreadsheet method shared above, is eToolLCD. While you can't use the EnergyPlus or OpenStudio files directly, you can model your building using eToolLCD to do a complete life cycle assessment.

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Last updated: Apr 11 '16