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Understanding Beopt Economic Analysis

asked 2023-11-27 17:18:24 -0500

Kent Thompson's avatar

updated 2023-11-29 09:55:39 -0500

I'm having a hard time believing the results of some of the beopt modeling that I'm doing. In my current model, the reduction of annualized energy related costs is about $200/year, but the present value of the optimized improvements is in the tens of thousands of dollars.

Beopt displays net present value in its output, correct?

What am I missing here?

I've attached the beopt file if anyone wants to look at the details.

https://www.dropbox.com/scl/fi/0jqs0y...

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answered 2023-12-06 18:36:37 -0500

I'm not entirely sure what you're asking or confused about...

The Min Cost point of your optimization shows a reduction in annualized energy costs of 200 USD/year, as you indicated. If you look at the utility bills alone (right-click on bottom-left graph and choose Graph Type > Utility Bills), you can see that there are savings of 1321 USD/yr. So approximately 1121 USD/yr is being spent towards efficiency improvements, which over the course of a 30 year analysis period, is indeed tens of thousands of dollars.

(I had to use "USD" instead of "$" because Unmet Hours kept messing up the formatting.)

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answered 2023-12-12 06:59:24 -0500

jpierce's avatar

updated 2023-12-12 07:02:38 -0500

The built-in help provides extensive details on this; at least it does in v2.8

Roughly-speaking, present value is what you could sell the home for, and AERC is utility bills plus excess mortgage over the reference condition. They are apples and oranges.

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Asked: 2023-11-27 17:18:24 -0500

Seen: 62 times

Last updated: Dec 12 '23