The Fractal Model was built by Fractal Energy Storage Consultants in 2015 to provide pre-construction technical design and financial analysis for utility-scale battery storage projects. Over the years, the tool grew in sophistication and earned license subscriptions from top utilities, developers and EPC companies around the world. Today, the Fractal Model strives to be the energy market’s choice for transparent, real-word storage investment analysis.

Standalone Storage or Hybrid System Analysis

The Fractal Model™ is a powerful technoeconomic energy storage and hybrid system modeling tool that provides investment grade analysis while simulating performance, degradation, warranty, costs and revenue to optimize the economics of your project. The Fractal Model platform is a MS Excel package with an additional JavaScript engine through a Microsoft 365 Add-In.

Project Development

Maximize long-term return for merchant and/or contracted business models. Optimize sizing and off-take structure. Determine bids for RFPs.

Due Diligence

Estimate degradation for various duty cycles and chemistries. Evaluate warranty options. Optimize degradation to maximize return.

RFP Bid Evaluation

Model impacts of CAPEX and OPEX. Estimate costs associated with auxiliary load, monitoring, maintenance, etc.


The Fractal Model features include:

  • Iterative Technical Design and Financial Analysis
  • Optimization of Project Revenues and Costs
  • Standalone Storage, PV+S (AC or DC), W+S, PV + W + S, PV + PV + S
  • Optimize Sizing and Degradation
  • Detailed Time Series Simulations (Hourly, Minute or Second)
  • Detailed Calculations: SOC, RTE, OPEX, CAPEX, ITC, Oversizing, Depreciation
  • Dynamic Scenarios (Run 5 Different CAPEX and OPEX)
  • Non-linear Degradation Curves That Capture Degradation Due to Throughput, DOD and SOC Across Six Lithium-ion Chemistries
  • RTE Losses in Accordance with Equipment Efficiency Curves (Batteries, Inverters, Transformers, Wires)
  • RTE Degradation (Batteries Become Less Efficient Over Time)
  • Optimized Dispatch Tool to Maximize Returns
  • Stack Applications and Create Custom Dispatches
  • Downloadable Cash Flow (annual and monthly)
  • Evaluate Business Models using Historical Prices or Forecasts
  • Sensitivity Analysis That Allows Year by Year Changes of Costs and Revenues
  • Maintenance and Monitoring Cost Estimates
  • Detailed Calculations of Peak Auxiliary Loads (Station Power)
  • CAPEX Pricing Tool (Fractal’s Estimated Costs)
  • Monthly Cashflows: Choose between annual or monthly (schedule outflows), add reserve funds (inverters and batteries), and add debt service
  • Milestone payment schedule to optimize monthly project capital outlay and accurately size capital stack
  • MMRA for optimizing operating cashflows related to battery augmentations and inverter replacement CAPEX; MMRA tax treatment functionality between OPEX and retained earnings
  • Easily toggle between unlevered and levered cases
  • Annual Costs of Auxiliary Loads on a Timestamp by Timestamp Basis
  • Solar Parasitic Load Cost Calculation
  • Track and Customize Degradation Separately for Augmentations
  • Optimize Between BOL Oversize and Augmentations with Self-optimized Simulations
  • Specify Cost Curves for Augmentations
  • Configure Topology: MV or HV Interconnect
  • Solve for Solar PV PPA Rate and Storage Capacity Payment
  • Federal and State Taxes and Tax Incentives
  • Arbitrage Tool (the Model Shows the Best Times to Buy and Sell)
  • ITC Compliance, MACRS, Bonus Depreciation
  • Major Maintenance Reserve Account
  • Account for Inverter Replacements
  • Calculate the Amount of Batteries Given the DOD, C-rate and SOC Restrictions
  • Optimize Around a POI Restriction
  • DC:AC Optimization for PV+S
  • Incorporate Third-party Forecasts and Dispatches
  • MA SMART and Clean Peak Incentive Calculators
  • Full Access to Formulas and VBA
  • Scenario Builder: Compare 4+ bids for CAPEX and OPEX
  • Self-optimization of BESS oversizing and augmentations based on IRR
  • Solar and BESS inverter throughput estimates, recommended replacement years and related CAPEX schedules with accounting treatments
  • Bridge loan / construction note facility for both solar and BESS CAPEX with debt sizing allocation relative to selected cost components
  • Heat map of residual capacity available at POI for optimal BESS value stacking
  • Specify costs of augmentations

Version 21.12 Newest Features and Functionality

Quarterly update Version 21.12 (released in December 2021) included the following features:

  • Detailed Tax Equity Model: Calculate partner returns and optimize tax equity sizing.
  • BESS Sizing for Solar Smoothing / Ramp Rate Control: Prepare for the upcoming GPC PVS RFP or projects requiring solar smoothing. Size a BESS that manages up to 1-second solar PV ramp rate.
  • BESS Sizing for Firming: Size a BESS that manages day-ahead forecasting errors.

Go to Fractal Model Website to Learn More

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