ECE/OPTI 4/514a NREL System Advisor Model Demonstration

1. Photonics Systems Laboratory Department of Electrical and Computing Engineering University of Arizona ECE/OPTI 4/514aNREL System Advisor Model Demonstration By: R.A. Juan M. Russo 2012-04-06

2. What is SAM? • Financial calculator that takes into account the time value of money. • PV: Present value • Complicated legislation on incentives • Energy rates • Costs: (initial, ongoing, installation, BOS, etc.) • Engineering calculator for system performance • Database of equipment or simple models. • Weather/location (incl. shading, tracking, etc.) • Energy consumption of the customer

3. Time Value of Money • What would you prefer? $100 USD today or $100 USD in a year? • Having the money today is more valuable than in a year. I could invest it, use it for an asset that produces income, etc. • What would you prefer? $100 USD today or $110 USD in a year? • Now, waiting to get the money is worth $10 USD. • Is it worth it? Depends on the financial environment…

4. TVM and Solar Energy • The system lifetime is long (20+ years) • System initial costs are high • System has ongoing costs throughout its lifetime • We need a metric that compares apples to apples: • Levelized Cost of Energy (or Electricity)

5. LCOE • In $/kWh is basically all the cost divided by all the energy the system will be able to produce. • Cost include initial, ongoing and financing costs. • LCOE treats energy as if it was money (so subject to TVM) • Will include incentives paid by Federal and State governments as well as utilities. • Nominal vs. Real: nominal takes into account inflation.

6. Costs • Direct Costs: • Inverter and modules (in $/WDC or $/Unit) • BOS: wiring, racking, etc. (in fixed $, per WDC or per area (m2) • Installation • Indirect costs: • Overhead type. • Permitting • Sales taxes • O&M costs: • $ Fixed, per kW installed, per MWh. All per year. • Maintenance costs

7. Performance (Energy Yield) • Choose location • Choose the PV module and Inverter • From model list or Enter your own parameters • Design your array: • Have SAM figure it out (tell SAM the desired array size) or Manually describe the array (Inverters, strings, modules/string, etc.) • Input system de-rates • Energy losses due to BOS components, soiling, etc. • Tracking or no tracking • Choose your model for incident radiation

8. Shading and Load • Shading: • If you know the shading of the site you can enter it here: in % shade vs hr of day or %shade at AZI and POLAR coordinates. • Electric load: • Customer provides a profile of the energy consumption of the household (i.e. from energy audit or recording device) • Helps determine real cash flow of the system.

9. Run your simulation • SAM will use TM2 weather data for the location entered and calculate performance for the first year. • Subsequent years are calculated based on first year and degradation rates, interest rates, escalation rates, etc.

10. Other features • Parametric simulations • Sensitivity analysis (tornado graphs) • Optimization • Statistical analysis • Compare systems • Links to MS VB for Applications and MS Excel • Proprietary Scripting language

11. Other tools out there • Specialized: • NREL SAM (U.S.) (free) • PVSyst from PVSyst SA (Switzerland) (800 CHF) • CAD interface for shading analysis • Optical and general Eng. tools: • Ray tracing software + MS Excel (may not take into account temperature) • MATLAB

12. Questions?