Solar + BESS Financial Model Template (Excel, 40-Year Forecast)

A Solar + BESS template is a pre-built Excel financial model that forecasts the economics of a solar PV farm paired with a battery energy storage system. This one runs a 40-year forecast broken down by month, covering solar yield, battery charge and discharge, capacity degradation, electricity price arbitrage, and project financing – returning NPV, IRR, and payback period. Free PDF demo available.

Solar + Battery Energy Storage System (BESS) Financial Model
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Investing in Solar PV and Battery Energy Storage Systems (BESS) is a powerful way to build a more resilient energy future. However, without a precise financial plan, these complex projects can be difficult to navigate and even more challenging to get funded.

Our comprehensive Solar + BESS Financial Model Template in MS Excel is a vital tool for anyone seeking to analyze, plan, and optimize their next renewable energy project. This robust Excel-based template provides a comprehensive framework for forecasting project financials, assessing feasibility, and maximizing returns with confidence.

Solar + BESS Template Specifications

AttributeDetail
Forecast horizon40 years, broken down by month
Time resolutionHourly and monthly — consumption, production, dispatch
Solar farm build-outInstalled capacity across up to 3 phases
Battery degradation methodsUp to 8 selectable methods
Charge sources modelled3 — excess PV only, full PV output, or grid purchase
Cycle trackingEquivalent Full Cycles (EFC)
Depth-of-discharge controlConfigurable, including a 20% minimum-load option
Battery replacement / expansionMultiple batteries over the project life
Revenue streams5 — cost savings, market sales, PPA, renewable energy certificates, battery reserve
Financial outputsNPV, IRR, payback period, free cash flow, debt schedule, investor cash flows
Scenario toolsSwitches to include/exclude PV and battery blocks, plus stress tests
ReportingExecutive Summary, Detailed Summary, presentation-ready slides
File format.xlsb (Microsoft Excel Binary Format)
Current version1.3
PricingFree PDF demo; $169.95 fully editable Excel

Why combine a solar farm with a battery (BESS)?

A standalone solar farm generates power only during daylight hours, limiting its revenue potential and leaving you vulnerable to grid fluctuations. By integrating a BESS in a solar power setup, you can store excess energy and discharge it when it’s most valuable, turning what used to be a limitation into a key revenue stream. This model helps you capitalize on hourly electricity price fluctuations to significantly increase profitability and project longevity.

Our financial model helps you tackle the key complexities of a Solar + BESS project, including:

  • Analysis of Excess Electricity Production by comparing expected consumption and Photovoltaic (PV) electricity production
  • Optimizing Battery Size: Determine the ideal battery capacity to meet your specific goals, whether it’s achieving energy self-sufficiency, selling power for profit, or providing a critical backup reserve.
  • Managing Battery Degradation: Accurately forecast the long-term impact of capacity fade and plan for future battery replacements to ensure your project remains profitable over its entire lifecycle.
  • Flexible Pricing opens Arbitrage Opportunities: Model the effects of hourly and seasonal electricity price fluctuations to find the most profitable charging and discharging strategy.
  • Ensuring Profitability: Justify the significant investment in a Solar + BESS Project by performing a detailed financial feasibility analysis that gives banks and investors the data they need to approve funding.

Who is this Solar + BESS template for?

This template is designed for a variety of use cases and is an indispensable tool for:

  • Developers and Consultants: Accurately forecast project financials for clients and optimize the Solar + BESS system for maximum profitability.
  • Investors: Evaluate the viability and potential return on investment of a Solar + BESS project with a clear, professional financial forecast.
  • Micro-grid Operators: Plan and optimize energy production and consumption for residential or commercial micro-grids.
  • Commercial & Industrial (C&I) Plant Owners: Determine the potential cost savings and financial benefits of adding a Solar Farm with storage to your facility.

What’s included in the Solar + BESS template?

Our model gives you complete control over your project’s financial planning with features that go beyond a basic spreadsheet. Go beyond basic assumptions with our unique features of Advanced Battery Modeling:

  • Detailed Financial Forecasting: Analyze your project’s performance with a comprehensive 40-year forecast, broken down by month for granular insight.
  • Flexible Inputs: Easily adjust key assumptions like solar capacity, battery size, and electricity prices to run a variety of scenario analyses and stress tests.
  • Electricity Consumption defines the needs and savings opportunities when installing a combined Solar + BESS project. Consumption is broken down by month and by the hour of the day.
  • Solar Farm Modeling covers the whole lifetime of the farm, including installed capacity in three phases, solar yields, and annual degradation. The expected output is broken down by month and by the hour of the day, allowing for the determination of the expected excess electricity production.
  • Electricity Prices: Benefit from a framework for capturing long-term price trends while modeling short-term pricing fluctuations by hour and by month. Use different assumptions to model the gap between electricity purchase and sales prices.
  • Batteries: You may include multiple Batteries to either replace old Batteries or expand the Battery Capacities over time.
  • Battery Capacity Degradation: The template includes up to 8 different ways to model the degradation of Battery Capacity over time, affecting the yield and lifetime of the Battery.
  • Battery Use: Specify whether you wish to charge the battery from excess PV production, the full PV production output from your solar farm, or purchase electricity from the grid to take advantage of price arbitrage opportunities. Easily analyze each of these three scenarios and understand the financial implications of those.
  • Battery Charge/Discharge Strategy: Select when the battery will be charged and discharged—using only excess solar, all solar production, or even buying electricity from the grid when prices are low—and see the financial impact of each strategy as well as the resulting Equivalent Full Cycles (EFC), which is critical for forecasting battery life. Either model the load cycles in a simplistic or a more detailed manner (by hour).
  • Battery Maximum and Minimum Load: Model scenarios where the batteries are only discharged down to 20% instead of a full discharge to address the recommendation of battery suppliers.
  • Battery Reserve: The model foresees an option to sell the Battery Reserve as an emergency power unit to potential third parties or use the reserve for your own use.
  • Revenues include the revenues from Savings in Electricity Costs, Electricity Sales at Market Rates or PPA, the combination with a Renewable Energy Certificate, and the potential sale of the Battery Reserve.
  • Comprehensive Financial Metrics: Automatically calculate essential metrics like Net Present Value (NPV), Internal Rate of Return (IRR), and Payback Period to quickly assess profitability.
  • Scenario Analysis through various switches to include/exclude PV and Battery Blocks, and adjustment parameters to key assumptions.
  • Investor Cash Flows: The model also allows you to project the cash flows to investors.
  • Professional Reporting: The template includes an Executive Summary, a Detailed Summary, and suggested presentation slides, so you can easily present your project’s financial case to stakeholders.
  • Many more features are also included in this template.

How does the battery modelling work?

You define the battery in three layers. First, sizing — capacity, number of units, and whether batteries are added later to expand or replace. Second, dispatch — whether the battery charges from excess PV only, from total PV output, or from grid purchases during low-price hours, and when it discharges. Third, ageing — which of the eight degradation methods applies, what depth of discharge you allow, and how the resulting Equivalent Full Cycles translate into capacity fade over the 40-year horizon.

Each layer feeds the next: changing the discharge strategy updates EFC, which updates the degradation curve, which updates yield and replacement timing, which flows through to NPV and IRR. That chain is what separates this from a static spreadsheet.

Why choose this Solar + BESS template?

Don’t waste time building a complex financial model from scratch. Our pre-built template provides a robust, easy-to-use framework that has been meticulously crafted to capture the unique complexities of a Solar + BESS project.

  • Optimize the Design and Size of your Solar + BESS Project
  • Evaluate Different Operating Scenarios
  • Prepare a Comprehensive Financial Forecast
  • Presentation Ready

Download our free PDF demo version to see the model’s structure and functionality.

Ready to take control of your project’s financial success? Combine the benefits of solar power with a BESS solution to take full advantage of the new opportunities in renewable energy markets. Get the Fully Editable Excel template Today!

The latest model version is Version 1.3, and the templates come as a Free PDF Demo Version and a paid, fully editable Excel Template.

File Types:

  • .xlsb (Microsoft Excel Binary Format, can be used with MS Excel).
  • .pdf (Adobe Acrobat Reader).

Solar + BESS template: Frequently Asked Questions

What is a Solar + BESS template?

A Solar + BESS template is a pre-built Excel financial model for a solar PV farm combined with a battery energy storage system. It forecasts generation, battery dispatch, degradation, revenues and financing to produce NPV, IRR and payback period.

Is there a free Solar + BESS template download?

Yes. A free PDF demo version is available on this page, showing the model’s full structure and outputs. The fully editable Excel version is $169.95.

Does the Solar + BESS template work in Excel?

Yes. It is supplied as an .xlsb file (Microsoft Excel Binary Format) and opens in Microsoft Excel. No add-ins are required.

How many years does the Solar + BESS financial model forecast?

40 years, broken down by month. Consumption, solar production and battery dispatch are also modelled by hour of the day.

How does the model handle battery degradation?

It offers up to 8 different methods for modelling capacity degradation over time. Degradation is driven by Equivalent Full Cycles (EFC), calculated from your chosen charge and discharge strategy, and feeds through to yield, replacement timing and returns.

Can I model electricity price arbitrage?

Yes. You can model hourly and seasonal price fluctuations and choose between three charging sources — excess PV only, full PV output, or grid purchases during low-price periods — then compare the financial outcome of each.

What revenue streams does the model cover?

Five: savings on electricity costs, electricity sales at market rates, sales under a PPA, renewable energy certificates, and sale of the battery reserve as emergency power.

Reviews

  • Initial Review

    This is an initial review, I have not gone through the model in detail, but will provide another review when I have completed detail review.

    Financial Model is structured perfectly for a multi-stakeholder analysis POV when evaluating the technical/financial fitness of a Solar/Storage EAAS for the customer, service provider, Investor, etc, Learning and understanding how model works is the easiest way to learn the most important factors in developing and evaluating a Solar/Storage EAAS, NICE!!!!

    Thank you for your feedback.

    87 of 186 people found this review helpful.

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