PV Power System Sizing and Configuration

1. PV Power System Sizing and Configuration Unit 7 Source:

2. Use Policy • This material was developed by Timothy J. Wilhelm, P.E., Kankakee Community College, with funding from the National Science Foundation as part of ATE Grant No. 0802786. • All materials in this presentation are designed and intended for educational use, only. They may not be used for any publication or commercial purposes. Source:

3. Author, Editors/Reviewers • Author: Timothy J. Wilhelm, P.E., Kankakee Community College • Editors/Reviewers / Modifier: • Chris Miller Heartland Community College Source:

4. Objectives • Students will be able to describe, in very simple terms, at least three differences ( hardware differences and/or operational differences) between a pure grid-tied solar-PV system and a stand-alone solar-PV system. • Students will be able to list, and briefly describe (in very simple terms), the basic steps for sizing a stand-alone solar-PV power system. Source:

5. Objectives • Students will be able to describe, in very simple terms, the general construction of a pure grid-tied solar-PV power system, listing its basic components. • Students will be able to describe, in very simple terms, electric motor effect and electric generator effect. Source:

6. Objectives • Students will be able to describe, in very simple terms, how motor effect creates back-torque in an electric generator. Source:

7. Simple Utility-Tied System Source: http://www.rhoduselectric.com/images/10-14-08/Solar_Electric_Systems.jpg

8. Utility-Tied PV • System is very simple, with few components. • System is sized almost strictly by budget. “How much can you afford to buy?” • System is modular and expandable in building-block-increments. • System does NOT provide back-up power when utility shuts down. • Can be configured to provide back-up power; but, involves additional equipment and more expense. • PV voltage approaches 600VDC!

9. Utility-Tied PVParts and Pieces • PV Modules and interconnect wiring. • Racks for mounting PV array. • Combiner boxes for parallel connection of series strings of PV modules. • GFP for roof-mounted, residential arrays. • Grid-tie inverter. • Lockable, outside disconnect. • Properly sized bi-directional breaker in distribution panel.

10. PV Modules

11. PV Module Interconnects Source: http://www.mrsolar.com/Merchant2/graphics/product/wiring/blue_unconnected.jpeg

12. PV Mounting RacksBallasted Pans for Flat Roof

13. PV Mounting RacksFixed Racks for Pitched Roof

14. PV Mounting RacksFixed Racks for Pitched Roof

15. PV Mounting RacksFixed Racks for Pitched Roof

16. PV String Combiner Box

17. Grid-Tie Inverters Source: http://hitechplumbingcorp.com/sitebuilder/images/SMA3000_Prod_sb3000us_md_20070727112949-167x174.jpg Source: http://www.altestore.com/store/descfiles/xantrex/inverters/gt3/Xantrex_grid_tie.jpg

18. Grid-Tie Inverters, Lockable AC Disconnect

19. Inverter Output to Main Panel Lockable Disconnect!

20. Simple Stand-Alone System Source: http://homepower.com/images/basics/Basics_SolarElect_OffGridFlow.jpg

21. Stand-Alone PV • System is more complex and more expensive than pure grid-tie. • System is sized by load analysis. • System is modular and expandable in building-block-increments. • System IS back-up power when utility not available. • Requires monitoring and battery maintenance. • You must operate within your ENERGY budget. • PV voltage typically 12VDC, 24VDC or 48VDC, nominal.

22. Stand-Alone PV -- Parts and Pieces • PV Modules and interconnect wiring. • Racks for mounting PV array. • Combiner boxes for parallel connection of series strings of PV modules. • GFP for roof-mounted, residential arrays. • PV Charge Controllers. • Batteries. • Inverter/Charger. • Load Center. • Disconnects and OCP, everywhere.

23. PV Charge Controllers Source: http://www.exploroz.com/images/Articles/349_Image1__TN180x200.jpg?6996 Source: http://www.enviroharvest.ca/images/Outbackmx60Controller.gif Source: http://www.readymaderesources.com/cart/images/uploads/xw60-150.jpg

24. Batteries • Lead Acid Cells are Standard • Flooded cell • Gel Cell SMF • AGM SMF

25. Batteries Source: http://shop.solardirect.com/images/pv-concorde-battery-d.gif Source: http://www.electric-cars-are-for-girls.com/images/6-volt-golf-cart-battery-Trojan-T-105.jpg Source: http://suntolight.com/imagenes/productos/S24SLD.jpg

26. Inverter/Chargers Source: http://www.alternativeenergydiscounthouse.com/images/products/VFX3648.jpg Source: http://www.msmelectric.com/mediac/400_0/media/Xantrex_SW.JPG

27. Put the pieces together… Source: http://img.diytrade.com/cdimg/476964/2901505/0/1162516202.jpg

28. Sizing a Stand-Alone System • See In-Class Worksheet • Do you have proper solar access? • Do your load analysis. • Size your battery – days of autonomy. • Size your PV array – recharge in a day (or two, max.) • Size system for worst-case conditions!

29. Grid-Tied with Batteries Source: http://homepower.com/images/basics/Basics_SolarElect_GridBBFlow.jpg

30. Final Notes • Illinois now has mandatory net-metering! • If you have utility available, USE IT! • 30% investment tax credit for next 8 years! • 50% grants/rebates available from State (maybe)! • Production tax credit?

31. Let the Sun Shine!