Solar + BESS Financial Model Excel Template

This model gives you complete control over your Solar + BESS project’s financial planning, with features that go far beyond a basic spreadsheet. Go beyond generic assumptions with our purpose-built Solar PV and Battery Energy Storage System modelling capabilities:

• Comprehensive 10-Year Financial Forecasting:

  Analyze your project’s full performance with a detailed 10-year forecast broken down by month providing granular insight into energy production, revenue ramp, EBITDA trajectory, and cash flow timing across every period.

• Simple Grey-Cell Input System:

  All assumptions are clearly marked with grey-colored cells on a single Driver’s Assumptions Sheet. Fill in your project parameters and the entire model i.e. energy production, revenues, costs, financial statements, and valuation which updates automatically.

• Solar Farm Modelling — Full Lifecycle Coverage:

  Model your solar farm across its complete lifetime with inputs for installed capacity (in MWh or MW), capacity factor, daily sunlight hours, average annual irradiance, and annual panel degradation rate. Solar output is projected month-by-month, revealing exactly how much energy is available for self-consumption, battery charging, and grid export.

• Advanced Battery Capacity & Degradation Modelling:

  Include multiple BESS units to expand capacity over time or replace degraded batteries. Model battery degradation using up to 8 distinct methodologies from simple annual percentage fade to detailed cycle-based degradation giving you an accurate picture of how capacity loss affects revenue and lifetime over 10 years.

• Flexible Battery Charge / Discharge Strategy:

  Choose exactly when and how your battery charges and discharges. Model three distinct operating modes:

  1. Charging only from excess solar PV production.

  2. Charging from the full solar output.

  3. Buying electricity from the grid at off-peak prices to sell at peak tariffs for arbitrage profit. The model calculates the resulting Equivalent Full Cycles (EFC), critical for accurate battery lifetime and replacement cost forecasting.

• Battery Maximum & Minimum Depth of Discharge:

  Model real-world operating constraints recommended by battery manufacturers such as discharging only to 20% State of Charge (SoC) rather than full depth of discharge and see the exact impact on usable capacity, revenue, and battery longevity.

• Monetize Battery Reserve:

  Model the option to sell your battery’s reserve capacity as an emergency power unit to third parties or retain it for self-use. The model calculates the revenue impact of this additional monetization stream separately.

• Electricity Consumption Modelling:

  Define your daily and nightly load requirements by month across the full 10-year horizon. The model automatically determines what portion of demand is met by solar, what is covered by battery discharge, and what must be imported from the grid establishing your baseline electricity cost savings.

• Electricity Price Framework, Capture Long-Term & Short-Term Trends:

  Model separate off-peak and peak tariffs for residential and commercial customers, with annual price escalation rates. Apply different assumptions for electricity purchase and electricity sales prices to accurately model the price arbitrage spread and your Power Purchase Agreement (PPA) revenue.

• Multiple Revenue Streams:

  The model captures every revenue source of a Solar + BESS project: electricity cost savings (self-consumption), daytime solar export at market rates or PPA tariffs, nighttime battery discharge export at peak tariffs, Frequency Regulation revenue, Capacity Market Payments, Ancillary Services Revenue, Renewable Energy Certificate (REC) revenue, and Battery Reserve sales, all with individual start dates and annual price escalation inputs.

• Separate CAPEX For Solar & BESS Asset Schedules:

  Model Solar CAPEX and Battery CAPEX completely separately, each with up to 12 asset line items covering purchase month, cost, useful life, and salvage value percentage. Automatically generates depreciation schedules and links to all three financial statements.

• Headcount & Payroll Planning:

  Plan your operational team with up to 30 roles including hire date, annual salary, annual increment %, bonus %, payroll tax %, and employee benefits all auto-linked to your monthly income statement.

• Operating Expenses with Inflation Escalation:

  Model 16 operating expense categories like Rent, Maintenance, IT Support, Insurance, Utilities, Legal, Accounting, and more, each with an individual start year, annual cost, and annual percentage increase for inflation modelling.

• Debt & Equity Financing:

  Model up to 4 equity investors (with equity %, desired return, and investment month) and up to 4 debt facilities (loan amount, interest rate, term, and payment frequency). WACC is auto-calculated using the CAPM model based on your inputs. Full loan amortization schedules are generated automatically.

• Short-Term Investment Modelling:

  Model excess cash deployed into short-term investments with investment type, amount, and timing to reflect realistic treasury management and maximize returns on idle capital.

• Scenario Analysis via On/Off Switches:

  Toggle the Solar PV block and/or the BESS block independently to model Solar-only, BESS-only, or combined scenarios. Compare the financial outcome of each configuration instantly without rebuilding the model.

• Investor Cash Flow Projections:

  The model projects cash flows specifically to equity investors including return multiples, IRR per investor, and post-money valuation giving you a clear picture of what each investor earns and when they can expect to exit.

• Professional Reporting:

  The template includes an Executive Summary tab, a detailed financial Summary tab, a visual Dashboard with charts, and structured output tabs for each financial statement ready to present to banks, infrastructure funds, energy investors, or your board without additional formatting.