Recent and Planned Improvements to the System Advisor Model (SAM)

Transcription

1 Recent and Planned Improvements to the System Advisor Model (SAM) 4 th Photovoltaics Modeling Workshop Aron P. Dobos 23 October 2015 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.

2 System Advisor Model (SAM) Combines detailed performance and financial models to estimate the cost of energy for systems Free: Models are country-agnostic 2

3 3 What s new in SAM for PV? PV-coupled battery energy storage for lithium ion and lead acid systems Lifetime simulations of PV systems for 30 years at subhourly timesteps Diffuse shading losses calculated from 3D scene PV module model using IEC test data

4 4 New Battery Model Designed for behind-the-meter analysis (residential and commercial scale systems) Lithium ion and lead acid chemistries including submodels for cell voltage, capacity, thermal, degradation, and replacements Highly configurable manual dispatch controller Integrated with PV system lifetime analysis to capture economic effects of capacity degradation and costs of replacement Incentives, complex utility tariff structures, and financing costs included in analysis. Validated with laboratory measured test data for two systems.

5 5 Storage Dispatch and Degradation Battery meets portion of load during peaks 4 kw PV system 2 kw peak load User input degradation with cycling and depth-of-discharge Battery replacements result in additional costs

6 6 Lifetime Simulations In this mode, PV system degradation is (correctly) applied to the DC output of the PV modules, and so can be used to assess inverter clipping levels as the system effective sizing ratio changes in time. DC power AC power (30 years) When the system is new, much more DC power is generated than inverter capacity, resulting in significant clipping. As the modules degrade and produce less power, clipping is reduced in the later years of the system

7 7 3D Shading Model Fully integrated into SAM Calculates linear beam shading losses and sky diffuse view factor loss Imports 2D mapping underlays from Bing maps Diurnal or hourly/subhourly time series shade simulation Upcoming new features: Estimation of nonlinear losses for shaded parallel strings Scripting to automate panel layout and import/export geometry data

8 8 IEC Module Model Dobos, A.; MacAlpine, S. Procedure for Applying IEC Test Data to a Single Diode Model. Proc. IEEE 40 th PVSC Conf. Denver CO, June, 2014

9 9 Other Recent SAM Improvements New user interface (November 2014) and native Linux version Added various metering (net, non-net, etc) options for complex utility bill calculations Batch simulations run in parallel on multiple processors for parametric and stochastic options Linux x86-64! Added a simplified LCOE calculator based on a FCR weather files included by default in CSV format Expanded scripting capabilities and new language support in SDK for PHP

10 10 Planned Upcoming Capabilities Option to input measured POA data for PV simulation (matched reference cell or broadband options) Automatic dispatch strategies for battery model including peak shaving, power limiting, others. Multiple input MPPT inverters New options for transient PV thermal models appropriate for short timestep modeling Calculation of nonlinear shading losses in systems with parallel strings based on method of Deline & MacAlpine (PVSC 2015) Validation and intercomparison of various 3D shading loss models

11 Questions SAM Team Aron Dobos Technical lead and project management Nate Blair Emeritus lead, on assignment to the World Bank Janine Freeman Photovoltaics, validation, and wind systems Nick DiOrio Battery systems Paul Gilman User support and documentation Steve Janzou Programming and financial models Ty Neises CSP models Mike Wagner CSP models Severin Ryberg Intern This work is supported by the US Department of Energy SunShot program. 11