1. EE379K/EE394V Smart Grids: Residential Power Quality
Scott Hinson,
Pecan Street Inc.
Ross Baldick, Department of Electrical and Computer Engineering
Spring 2017
Copyright © 2017

2. Source: Pecan Street Inc

3. Facts Worlds largest research energy use database
2,000+ devices being monitored
Energy monitors, electric/water/gas smart meters, smart thermostats, residential gateways
1,300+ residential participants in TX, CA, & CO
300 in Mueller neighborhood
210 with rooftop PV averaging 5.5kW
73 with Plug-in EV
3 transformers monitored
High-resolution water monitoring across Texas
>130 Million data points daily

5. Dataport

6. Research Reports Value of South vs. West facing PV arrays
Electric utility behavior and demand management programs
Rooftop solar panel generation compared to home electric use
Net impacts of rooftop solar panel generation on home grid demand
Portion of home electricity use devoted to heating and cooling
Reliability of Solar PV
Residential Water Use Index - First Edition

7. Mobile Apps

9. Electric Vehicle Measurement Value Apparent Power (VA) 3245 Power (W)
3209
Power Factor
.99
Current THD
10%

10. AC Compressor Measurement Value Apparent Power (VA) 1585 Power (W)
1491
Power Factor
.94
Current THD
14%

11. Refrigerator Measurement Value Apparent Power (VA) 150.6 Power (W)
149.9
Power Factor
>.99
Current THD
<7%

12. Computer Power Supply Measurement Value Apparent Power (VA) 148.8
Power (W)
144.6
Power Factor
>.97
Current THD
16%

13. TV Measurement Value Apparent Power (VA) 87.3 Power (W) 83.4
Power Factor
>.96
Current THD
25%

14. Lighting-CFL Measurement Value Apparent Power (VA) 24.65 Power (W) 14
Power Factor
.56
Current THD
121%

15. Lighting LED Measurement Value Apparent Power (VA) 17.9 Power (W) 12.1
Power Factor
.675
Current THD
109%

16. Harmonic Distortion (Continued)
THD Formula:
Total RMS Current:
If the fundamental current decreases for a fixed distortion current THD increases.
A traditional definition for THD does not account for current direction (RMS is sign neutral.)

17. Example Cases 15A 5A 10A 0A 50% THD Fundamental Current
Distortion Current

18. Solar Example 10A 5A 15A 7A (Total) 50% THD 250% THD 8A 2A
Fundamental Current
Distortion Current

19. Example Data

20. Example Data (Continued)

21. Example Data (Continued)

22. Participant 6836

30. Technical Need: Load and Generation Shifting
Source: Pecan Street Inc.

31. Solar Adoption and Costs
Source: EIA, CIA, World Bank, Bernstein analysis, Bloomberg article by Tom Randall
Source: Mike Shurtleff, Clean Technica

32. Homework Exercise: Due Tuesday, March 7
Create account on Dataport (ASAP, approval takes a day or two):
pecanstreet.org
2. For Data IDs: 26, 114, 370, 545, 547 considering data acquisition noise (ignore PV output less than 100W)
For each house, download the following data: “use”, “air1”, “car1”, “gen” use = what's being used in the home. air1 = HVAC compressor. car1 = Car charging. gen = generation. 
Please do NOT use “grid” data from database. Grid data in the database may not be accurate, so do NOT rely on that to balance power at each interval. Gird can always balance the net “use- gen”.

33. Homework Exercise: Cont.
calculate how many average minutes per year (for year 2015) solar generation is greater than (report the average value of 5 houses):
Total in home use.
Electric vehicle charging.
Air Conditioning use (Air1)
Air Conditioning plus car charging.
Calculate average number of kWh used in the homes.
Calculate average number of kWh generated.
Calculate average utility burden* for the homes.
*Burden = amount of energy delivered to, or received from the mains wires leading to the home. In the other words, the absolute value of net flow in wires.

34. Thank You Thank You Scott Hinson Director of Engineering
Pecan Street Inc.