8A-i

APPENDIX 8A. USER INSTRUCTIONS FOR LIFE-CYCLE COST AND PAYBACK 

PERIOD SPREADSHEET

TABLE OF CONTENTS

8A.1 INTRODUCTION .........................................................................................................1

8A.2 MODEL CONVENTIONS............................................................................................1

8A.3 INDIVIDUAL WORKSHEETS....................................................................................1
8A-1

APPENDIX 8A. USER INSTRUCTIONS FOR LIFE-CYCLE COST AND PAYBACK 

PERIOD SPREADSHEET

8A.1 INTRODUCTION

The results obtained for the life-cycle cost (LCC) and payback period (PBP) analyses can 

be examined and reproduced using the Microsoft Excel spreadsheet available on the 

U.S. Department of Energy (DOE) Building Technologies website at: 

http://www1.eere.energy.gov/buildings/appliance_standards/commercial/metal_halide_lamp_fixt

ures.html.

There is one spreadsheet covering all combinations of metal halide lamp fixture system

equipment classes. The spreadsheet posted on the DOE website represents the latest version that 

has been tested with both Microsoft Excel 2007 and 2010. The LCC and PBP spreadsheet 

performs calculations to forecast the change in LCC from an energy conservation standard and 

the PBP that such a change implies. These concepts are explained in the main body of 

preliminary technical support document (TSD) chapter 8. 

To operate the spreadsheet, a user simply describes the operating hours and economic 

growth scenarios desired for examination. Any market and energy price behaviour can be set by

adjusting the named ranges throughout the LCC/PBP spreadsheet model. Therefore, strictly 

speaking, there are no “instructions” necessary to operate the spreadsheet. Rather, in this 

appendix, DOE provides a description of the model in case users wish to examine DOE’s 

assumptions and methods or to test alternative assumptions.

8A.2 MODEL CONVENTIONS

Both of the model’s primary outputs, LCC savings and PBP, are calculated on the LCC 

worksheet by using base case and standards case as inputs (e.g., the LCC for a particular metal 

halide lamp fixture system is calculated by subtracting the LCC associated with that unit from 

the LCC associated with the same unit at CSL 0).

In general, logic flows from data sources and assumption (assembled on the right-most 

worksheets) toward outputs (produced on the left-most worksheets). Further data carried from 

one sheet and reproduced in another are generally presented in a box on the upper-left side of a 

worksheet. 

8A.3 INDIVIDUAL WORKSHEETS 

The LCC/PBP spreadsheet or workbook consists of the following worksheets described 

below.

Instructions This worksheet contains notes from the model developers for each 

other and for spreadsheet users.
8A-2

LCC&PBP This worksheet presents LCC savings and PBP results by metal 

halide lamp fixture type to produce the results that DOE provides 

in the preliminary TSD executive summary and chapter 8. This 

worksheet also condenses the information from the Lifetime Costs 

worksheet, for user ease of use.

Lifetime Costs This worksheet compiles data from several other worksheets to 

calculate the actual life cycle costs of each metal halide lamp 

fixture. This worksheet also contains assumptions for labor costs, 

some equipment prices, and mark-up values.

Discount Rate This worksheet derives discount rates for commercial, industrial, 

and outdoor stationary sector metal halide lamp fixtures.

Operating Hours This worksheet provides the data and calculations used to develop 

operating hours for commercial, industrial, and outdoor stationary 

sectors.

Electricity and Tax Rates This worksheet contains data and calculations for electricity prices 

over time, and sales tax rates. Economic growth scenario 

information is also contained in this worksheet.

Information Hub This worksheet contains the engineering summary data, and many 

important quantities that pertain to each equipment class and 

representative piece of equipment. 

Output to NIA This worksheet contains a few calculated values for easy output to 

the NIA model.