M e m o r a n d u m
FROM:
Michael Baker, SBW
TO:
RTF Staff
DATE:
February 11, 2013
RE:
Phase I Review and Update Recommendations: Commercial Grocery Open Display
Case LED Lighting
This memo documents the results of SBW’s detailed review of the UES (Unit Energy Savings) measure
Commercial Grocery Open Display Case LED Lighting. This measure has been classified by RTF staff as
Proven. The measure covers energy savings that result from installation of LED lighting in open grocery
display cases (“multi-deck” cases) as an upgrade from T-8 or T-12 lighting, and savings that result from
removal of a T-8 or T-12 lamp (delamping). The upgrade measures apply to new and existing grocery
display cases. The review focused on the derivation of the measure Unit Energy Savings (UES).
Summary Recommendation. The status of this measure should be changed to Out-of-compliance.
The following recommendations lead to a change in status to Out-of-compliance.
1. The Hours of Operation parameter needs to be based on metered data.
2. The Average EER parameter needs to be derived transparently from publically available regional
data.
The following recommendations lead to a change in status to Under Review.
1. Workbook needs to be updated to use latest ProCost template, which includes Measure Cost
and EUL summary worksheets.
2. The efficient-case Lamp Power Use needs to be based on program data of installed LED lighting.
3. The Portion of lamp energy rejected to the refrigerated space parameter should be based on
measured data or engineering analysis.
4. The source for the Lamp Location Weighting needs to be more fully documented.
Limitation of Review. None
Alterations to Workbook and Documentation.
2820 Northup Way, Suite 230
Bellevue, WA 98004
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The “Summary” tab was renamed to “Summary 9-28-2010,” reflecting the RTF decision date to
adopt a status of Under Review for the measures.
A sheet called “Summary” was added to the workbook. The sheet describes how measures are
identified, lists important constants and their sources, describes the savings estimation
algorithm and the associated baseline and efficient case parameters and their sources for each
measure and UES component. This tab is an update to the “Summary 9-21-2010” tab, and shows
the results of this detailed review.
Recommendations for Updates. The RTF should implement the following recommendations:
1) Workbook Structure and Formulas
a) Workbook needs to be updated to use latest ProCost template, which includes Measure Cost
and EUL summary worksheets. This deficiency causes a change of status to Under Review.
2) Documentation
a) A fuller accounting needs to be provided for the Lamp Location Weighting. The workbook
Summary tab states that the weighting is derived from PECI audit data, and results are
summarized. The source data should be more fully documented. This problem causes a change
of status to Under Review.
3) Measure Definition
a) No changes recommended
4) UES Savings Estimation Method
a) No changes recommended
5) Input Parameters
a) The Hours of Operation parameter needs to be based on metered data. The measures currently
assume one of two possible values of either 18 or 24 hours per day on-time. The source for
these hours is not clear. This deficiency causes a change of status to Out-of-compliance.
b) The Average EER parameter is based on proprietary DOE 2.2-R simulations of Northwest grocery
environments. This parameter needs to be derived transparently from publically available data.
This deficiency causes a change of status to Out-of-Compliance.
c) The source for the Portion of lamp energy rejected to the refrigerated space parameter is listed
as “DOE Rulemaking.” The rulemaking file we found1 cites EPRI and Supermarket Simulation
Tool as the sources for a value of 50% for lamps outside the air curtain. We could not find the
1Commercial
Refrigeration Equipment Final Rule Technical Support Document, DOE,
http://www1.eere.energy.gov/buildings/appliance_standards/commercial/pdfs/chp_5_cre_engineering_fi
nal.pdf
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source for the 100% value used in the workbook for “shelf” lighting. The 100% value is clearly an
overestimate. The 50% value sounds like a rough estimate. This parameter should be based on
measured data or engineering analysis. This deficiency causes a change of status to Under
Review.
d) The source for the efficient case Lamp Power Use is simply listed as “Manufacturer’s Specs.”
PECI informed us that at the time the measure was developed, no data existed to determine the
actual weighted average power draw of installed lighting strips, but that data now exist. This
parameter should be based on program data. This problem causes a change of status to Under
Review.
Additional Considerations
1. Sunset: Due to the fast-changing nature of LED technology, this measure should be reviewed
every two years.
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The status of this measure should be changed to Out-of