Tier 2 Advanced Power Strips Revisiting Behavior Based Models for Estimation of Savings in Laboratory and Field Trial Evaluations Michael J. Klopfer, Joy Pixley, Klint Segarra, G.P. Li California Plug Load Research Center ENERGY EFFICIENCY IN DOMESTIC APPLIANCES AND LIGHTING 2107 September 13, 2017 calplug.uci.edu
Scope: Review of Tier 2 APS technology in addition to testing and measurement methodologies in lab and field environments. Presentation Outline: Introduction Technology Overview Laboratory Evaluation Models Field Testing Considerations Conclusions
Introduction AV and PC Plug Load Impact: Peters, 2010; Conti, 2014; Valkimi, 2015
Introduction AV Plug Load Impact: 430-685 kwh for A/V Devices for Ca. households 2,000 kwh household annual Ca energy usage (per capita) PG&E, 2015
Introduction Advanced Power Strips (APS) provide: Control of connected devices Reduction of wasteful energy use Intelligent device control VS Multiple types (Tier 1, Tier 1+, Tier 2)
Tier 1 Advanced Power Strips Introduction
Introduction Tier 1 Advanced Power Strips Saves energy by turning off accessory devices Standby power reduction ~ 10% - 20% savings potential But what if master device is left on?
Introduction Tier 2 Advanced Power Strips for Residential A/V (Simplified Master-Control Operation)
Introduction Tier 2 Advanced Power Strips Saves energy by turning off accessory devices Standby power reduction Turns off unused master devices ~ 25% - 50% savings potential IR and IR+OS Types Savings are dependent upon usage Savings dependent upon measurement method! PG&E, 2015
Laboratory Evaluation What devices are in use? How are the devices used? How does the sensing capability interact with the user(s)? How does the timer setting on the Tier 2 APS affect savings?
Laboratory Evaluation
Laboratory Evaluation A Tier 2 APS is modeled as a Tier 1 APS with additional savings potential and with inherent energy usage factored in: Last term! (the tricky one) (Tier 1) (inherent energy usage)
Laboratory Evaluation We must assume there is a gap between when the Tier 2 APS will un-power devices and when the user would naturally turn the device off to achieve additional, legitimate savings: How do we get this?
Laboratory Evaluation Active are users when watching TV? We put it to the test! Confirmation: The usage and reduction agrees with the Ca T2 APS Field Trial!
Laboratory Evaluation Using more external information, the model builds up for all devices:
Impact of occupancy sensor: Laboratory Evaluation
Field Testing Considerations IR, Masterless IR, Masterless IR+OS, Master/Control Participants in 2015/2016 Ca Tier 2 APS AV Field Trial Two methodologies used for measurement: Pre-Post and Log Mode Only (LME)
Field Testing Considerations Log Mode Evaluation (LME) Method:
Field Testing Considerations Log Mode Only (LME): One period of measurement Great for initial evaluations (does not cause user impact) Uses a modified product Relies on assumptions in usage Clear potential modes of failure for underestimating or overestimating savings Requires a predictable response from users
Field Testing Considerations Pre-Post Method: Pre Post
Field Testing Considerations Pre-Post Evaluation Two measurement periods which are assumed to be identical Device functions as normal, can impact user Classic method for M&V Random error between sessions can cause overestimation or underestimation of savings Carefully controlled Pre-Post relies on fewer assumptions than LME and is easier to defend.
Field Testing Considerations Method Comparison: PG&E, 2015
Conclusions A model for Tier 2 APS operation in the laboratory has been developed. This model can be used to model power savings potential for other control schemes beyond Tier 2 APS. Evaluating the performance of energy saving devices that use control requires assumptions based on modeled behavior. Two methods are used for Evaluating Performance of Tier 2 APS devices in field trials, both have merit and are effective. As effectiveness leads to efficiency in device development, carefully controlled Pre-Post is a more robust, easier to defend method than LME. Tier 2 APS Qualified Product List based on evaluation results (PG&E) The book is usually better than the play: go read the conference paper much detail was glossed over.
Thank You
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