1. NREL is a national laboratory of the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy operated by the Alliance for Sustainable Energy, LLC The Solar Advisor Model PV and Inverter Models Nate Blair Aron Dobos Chris Cameron Mike Wagner October 30, 2009

2. Contents Model Overview TRNSYS Overview Module Models Inverter Models CSP Models - Brief Overview 2 National Renewable Energy LaboratoryInnovation for Our Energy Future

3. SAM Vision Combine PV, CSP, solar hot water technologies into a single model Make high-quality performance models developed by NREL, Sandia, and other partners available to a wider audience Facilitate comparison by handling performance, costs and financing consistently across technologies Facilitate calculating the impact of R&D on LCOE, NPV, etc. in various markets. Sensitivity analysis and graphing capabilities High emphasis on GUI to promote greater usage of quality tools by industry and DOE. Don’t reinvent the wheel 3 National Renewable Energy LaboratoryInnovation for Our Energy Future

4. Results Inputs SAM Component Parameters Financial Assumptions Financial Metrics: LCOE, IRR, NPV, Payback, etc. Weather Data Costs Block Diagram Incentives Utility Rate Structure Hourly Simulation Financial Model Sensitivity Analysis Detail: Hourly Energy Flows, Cash Flow Performance Metrics: Capacity Factor, Annual Output 4 National Renewable Energy LaboratoryInnovation for Our Energy Future

5. SAM Processes input data to calculate hourly output and cash flow TRNSYS simulation engine –Uses component models developed by the SAM team Sensitivity analysis: Multiple simulations SAM Hourly Simulation Financial Model Sensitivity Analysis 5 TRNSYS is developed and maintained by the Solar Energy Laboratory of the University of Wisconsin at Madison. http://sel.me.wisc.edu/trnsys/ TRNSYS is developed and maintained by the Solar Energy Laboratory of the University of Wisconsin at Madison. http://sel.me.wisc.edu/trnsys/ National Renewable Energy LaboratoryInnovation for Our Energy Future

6. SAM Solar Performance Models PV Modules –Simple efficiency model with temp. coefficient –Simple eff. model for concentrating PV –Sandia PV Array Performance Model –CEC/Wisc 5-parameter model –PV-Watts model (with option of simple storage & loads) Inverters –Single-point efficiency inverter model –Sandia Inverter Performance Model CSP –Parabolic Trough (based on NREL’s Excelergy model) –Dish Stirling –Power Towers Generic –Very simple capacity * capacity factor model for comparison with non-solar technologies Red = new or modified in SAM 2009 6

7. Sandia PV Array Performance Model 7 10 inter-related empirical equations that take a variety of inputs: –ambient temp –direct and diffuse radiation –module characteristics –array layout 30 Coefficients derived from measured data provided in a free Sandia database Recommended model for included modules Extensive testing to determine coefficients is cost-intensive so recent modules may not be available

8. CEC/Wisc 5 - Parameter PV Performance Model 8 Developed specifically to allow for the use of standard manufacturers' data - the primary parameters to the model The CEC uses this for their free tool as part of the New Solar Homes Partnership program –The CEC provides the five parameters for all approved modules. –The CEC and/or others can create the necessary data based only manufacturers’ data. Drawback: Lack of independent validation of the manufacturer’s data

9. Simple Efficiency PV Model Multi-radiation level efficiency model Temperature correction from Sandia PV model Great for future module analyses or feasibility analyses.

10. Sandia Inverter Model 10 The minimal amount of information is the manufacturer's specifications. The CEC has, in conjunction with Sandia, created a free database of current, commercially available inverters A single-pt efficiency inverter model available if desired inverter not present.

11. Simple Efficiency Inverter Model

12. PV-Watts PV-Watts has been a model from NREL for many years. Simple efficiency model with temperature correction that includes inverter derate. Used extensively for various subsidy programs. SAM 2009 version includes: battery storage option ability to enter monthly/hourly load data

13. Parabolic Trough Model Components Solar Field Thermal Storage and Dispatch Logic Powerplant (Turbine) Weather Relatively simple non-thermodynamic model Based on industry-known code (Excelergy) Plan to incorporate thermodynamic cycle Almost no other CSP performance/cost/financing models available

14. Dish Stirling Component Model Mirror SystemReceiverStirling Engine Weather Based on recent student thesis models validated with real data Field of dish systems modeled as aggregate of individual system

15. Central Receiver (Power Tower )Component Model Heliostat Field (Mirror Field) Tower Receiver Powerplant Weather Based on recent student thesis models validated with real data Uses DELSOL (Sandia Code) to optimize position of heliostats if desired Field of dish systems modeled as aggregate of individual system Thermodynamic powerplant model DELSOL Code (optimized field layout)

16. “Generic” Performance Model Very simple performance model –Output = Cap * CapFact * Perf. Factors Useful For: –Solar Technologies not yet implemented in SAM (power towers) –Future technologies –Non-Solar technologies (wind, geothermal, hydro, etc) –Compare solar with conventionals (coal, gas, etc.) –Policy or Incentive Analysis where specific performance not critical

17. Getting Help Online Help and User Guide –Help menu and buttons SAM Website –http://www.nrel.gov/analysis/sam Google Groups –http://groups.google.com/group/sam-user-group Email User Support –Solar.Advisor.Support@nrel.gov 17 National Renewable Energy LaboratoryInnovation for Our Energy Future

18. Live Demo! Solar.Advisor.Support@nrel.gov http://www.nrel.gov/analysis/sam 18 National Renewable Energy LaboratoryInnovation for Our Energy Future

19. Thank you! solar.advisor.support@nrel.gov http://www.nrel.gov/analysis/sam 19 National Renewable Energy LaboratoryInnovation for Our Energy Future

20. Links to an External Workbook SAM Inputs “SentTo” Excel 20 “CapturedFrom” National Renewable Energy LaboratoryInnovation for Our Energy Future