EnergySmart Grocer

2 BPA background  The Bonneville Power Administration contracted Cascade Energy Engineering, Inc. to evaluate the GrocerSmart audit tool prior to use in their programs. –Cascade noted eight areas of possible improvements to the GrocerSmart 2.0 program.

3 BPA background and GrocerSmart 3.0  All of these improvements have been implemented minus one.  In addition, GrocerSmart has undergone a number of additional improvements, resulting in the release of GrocerSmart version 3.0.

4 Outstanding improvement  Cascade Comment #1: The model overestimates savings if multiple interrelated measures are implemented. –Why? Savings are calculated for each measure individually, using a common baseline –How? –If a measure that changes the refrigeration load is implemented with a measure that changes the refrigeration system efficiency. Or –If multiple measures are implemented that change the refrigeration system efficiency.

5 Outstanding improvement - Impact –Quick Example (site level savings – micro look) Measure A = system improvements that reduce the EER from 8.3 to 4.3 (single to high efficiency multiplex w/VFD & floating head and suction) Measure B = load improvements that reduce the load from 880 BTUH/lf of case to 118 BTUH/lf (low temp open to reach-in)

6 Outstanding improvement - Impact –Quick Example Savings Measure A = 48% Measure B = 87% Measure A+B = 135% (no interactions) –If measure A and B are done at the same time: Measure A&B = 93% (including interactions) Note: this is an extreme example

7 Outstanding improvement - Impact –Quick Example (program savings – macro look) Results from a past program Frequency of occurrence –7% of the 1,258 stores Affected savings –6% of 51.5 million kWh Impact on savings –<2% (using the extreme example) –<1% (likely impact)

8 Outstanding improvement  Recommendation: To correct his issue, multiple system measures or a system with a load measure must be analyzed incrementally in sequence or as a group. Note: some system measures are already analyzed together.

9 PECI Solution parameters  Only installed savings, reported to the utilities, will reflect interactive impacts.  Installed savings will not be adjusted for interactions on stores that do not require it. GrocerSmart will identify and direct users to those stores requiring calculation of interactive savings.  Installed savings, previously calculated, will never be overwritten.

10 PECI Solution – The packaged approach  Packaged Approach –Savings are calculated for each interactive measure individually (this is done currently). –Savings are calculated for a single “package” of all installed interactive measures. –Individual savings are multiplied by the ratio of the package savings to the sum of the individual savings, thus adjusting the individual savings for interactive impacts.

11 PECI Solution – The packaged approach  Installed savings for each measure would be calculated as follows: (GS savings)*ARinstalled*ARinteract where Ainstalled = [(installed count)/(GS count)] Ainteract = [(GS package savings)/(sum GS individual savings)]

12 PECI Solution – The packaged approach  Installed savings for each measure would be calculated as follows: (GS savings)*ARinstalled*ARinteract where Ainstalled = [(installed count)/(GS count)] Ainteract = [(GS package savings)/(sum GS individual savings)]

13 Packaged Approach - Advantages  accurate site savings  the process can be fully automated; no user input or interaction would be required  there would be no changes in the way the users interact with GrocerSmart.

14 Packaged Approach - Disadvantages  Every EEM savings will be adjusted regardless of whether the EEM has savings interactive with other measures. –This will be addressed by only including measures that are logically impacted by significant interaction. Ie. lighting measures would be excluded, while refrigeration load and efficiency measures would be included in the interactive adjustment process.  Reported measure savings may be quite variable across the program depending on the groups of measures.  All EEMs will take on the load shape of the site even if the EEM itself has a flat load shape.

15 Other considered methods  Stepwise Approach –Calculating savings sequentially in a prescribed order  Advantage: –accurate site savings  Disadvantage: –Order in which measures evaluated would be arbitrary –Reported measure savings variable across program –Substantial amount of human interaction for every run

16 Example Comparison Packaged Approach: AR = 93%/135% = 69% Measure A’ = 48%*69% = 33% Measure B’ = 87%*69% = 60% Measure A’+B’ = 93% Stepwise Approach: Measure A1 = 48% Measure B2 = 45% Measure A1+B2 = 93% Measure B1 = 87% Measure A2 = 6% Measure B1+A2 = 93% Savings from the previous example: Measure A = 48% Measure B = 87% Measure A+B = 135% (no interactions) Measure A&B = 93% (inc. interactions)