P14421: Smart PV Panel

1. P14421: Smart PV Panel Bobby Jones: Team Leader Sean Kitko Alicia Oswald Danielle Howe Chris Torbitt

2. AGENDA • Project Overview • Heat Analysis • Electrical Design • System Layout • Test Plans • BOM • MSD II Schedule

3. Project Overview

4. Project Overview • Advance Power Systems • Jasper Ball • Atlanta, GA • Snow reduces power output of PV panels • Develop method to prevent snow from accumulating in the first place • Apply current to conductive, heating ink • Keep temperature of panel surface above freezing • Sense presence of snow

5. Heat Analysis

6. Heat Analysis Process • 1 How much power is produced by the panel if there was no snow • Uses TMY3 data which is the most average months weather in Rochester • Calculates solar beam angles on panel based on time of day and day of year and angle of panel tilt • Calculate how much energy panel produces from TMY3 data, solar beam angle, efficiency of panel (19%) and area of panel (0.024m)

7. Heat Analysis Process con’t • 2 Find energy required to heat the panel in between ink traces to 5°C • Length and spacing determined by cell size. • Limited to where bus bars on cells were • Coefficient of convection (h) ranges from 5 to 28 • Modeled sections of cell using fin analysis • Was able to calculate m, to get temperature at ink and qfin

8. Cell

9. Heat Analysis Process con’t • 3 Calculate total energy • qfin values already calculated • Calculate qmelt based on an average snowfalls rate over 4 hours • Uses ice properties (h=33400J/kg) • Assumes density of snow=60 kg/m2 • Calculated qrad • Uses glass properties and surrounding temperature • Total qgen is the sum of these in each section

10. Heat Analysis Process con’t • 4 Compare different ink configurations based on qgen calculation • qgen was calculated based on sections of a cell • Calculations for configsbased on an entire panel, not just one cell • Conclusion: Configuration 2 is the more efficient in all cases

11. Configuration 1 16 Sections 8-0.013 Sections 8-0.052 sections

12. Configuration 2 8 Sections 8-0.039 Sections

13. Configuration 3 4 Sections 4 0.078 Sections

14. Configuration 4 10 Sections 4-0.031 Sections 4-0.052 Sections 2-0.029 Sections

15. Heat Analysis Process con’t • 5 calculated specific convection coefficient for each hour of the day it snows • Uses TMY3 data • Does not take into account the direction of wind or the angle of panel • Temperatures all rounded to nearest degree • Conclusions: All Reynolds's numbers were <5*105 therefore all used laminar model

16. Heat Analysis Process con’t • 6 calculated energy required for snow prevention on panel • Uses h that was calculated • Uses same process as qgen calculation but uses data for that specific day • Snow data could not be found on hour basis, so assumed snows for four hours when most energy could be generated

17. Heat Analysis Process con’t • 7 find how much light gets to the panel when snow is left to accumulate • Uses equation found on next slide • Equation used when there is snow accumulation. • As time moves forward, the snow accumulates • Snow is assumed to be left on panel for the rest of the day • Each day it is assumed there is not snow starting on the panel

18. Percentage of Light vs. Snow Depth

19. Heat Analysis Process con’t • 8 Graphically compare results • Took the amount of energy required to melt snow over four hours (when there was snow) and subtracted that from how much energy the panel would produce with no snow • Took the calculated amount of light that would get through the snow and graphed that

20. January 2

21. February 10

22. March 5

24. Energy Conclusion: • Total energy for one year if snow is prevented: -7.5*107J (-20,823Wh) • Total energy for one year if panel was left alone: about 3,300,000J (916.5Wh) • Snow prevention is not the best way to get rid of snow from an energy standpoint • Suggest seeing energy consumption if snow is allowed to accumulate then heated up to slide off. Only found through testing.

25. ANSYS – Heat Transfer

26. Electrical Design

27. Sensors

28. Sensors

29. Sensors

30. Sensors

31. Sensors

32. Simulations

33. Simulations

34. Simulations

35. Power Electronics

36. Power Usage Don’t want the battery to go below 40% Capacity Takes into account Efficiency in Cold Temperatures

37. Power Electronics Schem

38. Solid State Relay

39. Regulators • BP5275 Series • MAX1681

40. Battery and Controller • Trojan 31-AGM Battery • Getting a free AGM battery from a contact at Renewable Rochester • Morningstar SS-20L 20 Amp PWM Solar Charge Controllers w/LVD ($78)

41. POC CONTROL SYSTEM • Atmel's ATMega328P 8-Bit Processor in 28 pin DIP package with in system programmable flash Features: •32K of program space •23 programmable I/O lines 6 of which are channels for the 10-bit ADC. •Runs up to 20MHz with external crystal. •Package can be programmed in circuit. •1.8V to 5V operating voltage •External and Internal Interrupt Sources •Temperature Range: -40C to 85C •Power Consumption at 1MHz, 1.8V, 25C –Active Mode: 0.2mA –Power-down Mode: 0.1μA –Power-save Mode: 0.75μA (Including 32kHz RTC)

42. POC CONTROL SYSTEM Con’t

43. POC CONTROL SYSTEM Con’t

44. POC CONTROL SYSTEM Con’t

45. POC SENSOR RESEARCH

46. Enclosure

47. Enclosure and Layout

48. BILL OF MATERIALS

49. Risk Assessment and Mitigations

50. TEST PLAN OUTLINE • Heat Transfer Test • Explores how heat propagates through glass from electrified trace • Apply a DC voltage to ink trace • Use thermocouples to measure temperature of glass at various locations • Multiple applied voltages, multiple ink trace resistances • Steady state and transient