Battery Energy Storage Systems (BESS), Financial Model, Renewable Energy, Solar

10-year Financial Projections, 5-year Financial Projections, CFO, Debt Schedule, Debt Service Coverage, EPC, Excel, Financial Analysis, Financial Debt, Financial Feasibility, Financial Model, Financial Modeling, Financial modelling, Financial Projections, Financial Ratios, Financing, Free Cash Flows, Investing Cash Flows, IRR (Internal Rate of Return), LLCR (Loan Life Coverage Ratio), NPV (Net Present Value), Payback Period, Project Finance, Risk-Adjusted NPV, Three Statement Model | Three Financial Statements, WACC (Weighted Average Cost of Capital)

What is Helios Nexum™?

Helios Nexum is a professional-grade Excel financial modelling framework designed specifically for hybrid solar photovoltaic (PV) and battery energy storage system (BESS) projects. It combines an 8,760-hour hourly energy simulation engine with a fully integrated project finance framework, enabling analysts, developers, and investors to evaluate hybrid renewable assets under realistic operational and market conditions.

The model is available in two editions: the Lite Edition provides a static, hardcoded output version suitable for quick analysis and orientation; the Pro Edition unlocks the full hourly dispatch engine, live API data integration, and advanced financial modelling capabilities.

The Industry Challenge

Renewable energy developers increasingly face complex operational and financial risks driven by grid congestion, curtailment, and volatile electricity markets. Traditional project finance models typically assume static annual generation and simplified revenue assumptions — an approach that was historically sufficient for standalone solar assets but fails to capture the operational complexity of modern hybrid renewable systems. As solar generation scales globally, projects encounter grid export constraints, curtailment during high-generation periods, and the need to integrate battery storage for revenue optimisation. Without a modelling framework that reflects these dynamics, analysts cannot properly evaluate revenue stacking opportunities, battery utilisation strategies, curtailment impacts, or realistic project cash flows. Helios Nexus™ was built to solve exactly this problem.

What is it used for?

Helios Nexum is built for investment appraisal, project development evaluation, and financial due diligence on hybrid solar + BESS assets. It enables users to move beyond simplified annual generation assumptions and evaluate how hourly operational behaviour — including battery dispatch strategies, curtailment events, and electricity price volatility — translates into project-level financial performance.

Typical use cases include:

Preparing investment committee and lender presentations
Evaluating the financial impact of grid curtailment and export constraints
Comparing solar-only versus hybrid project structures
Stress-testing revenue assumptions across multiple scenarios
Sizing debt, mezzanine, and equity for project finance transactions

Main Features and Highlights

8,760-Hour Solar Generation Engine Simulates hourly solar production across the full year using location-specific irradiance profiles, providing a realistic and granular view of generation behaviour rather than relying on simplified annual P50 yield estimates.

Battery Dispatch Simulation Models battery charge and discharge behaviour across the full simulation period, capturing energy arbitrage opportunities, solar shifting strategies, and revenue optimisation logic at hourly resolution.

Curtailment and Grid Constraint Modelling Allows users to define export limitations and grid congestion scenarios, quantifying the financial impact of curtailment on project revenues and returns — a capability increasingly critical as solar penetration grows across global markets.

Revenue Stacking Analysis Separates and quantifies revenue contributions from solar generation, battery arbitrage, and hybrid optimisation strategies, enabling a clear understanding of how each revenue stream contributes to overall project economics.

Live Data API Integration (Pro Edition) The Pro Edition connects directly to leading energy data sources — including PVGIS for solar irradiance, ENTSO-E, Elexon, and NESO for European and UK electricity market prices, and EIA for US energy data — eliminating manual data entry and ensuring model inputs reflect current market conditions.

Project Finance Framework A fully integrated financial model covering project cash flows, CFADS calculation, debt service schedules, and capital structure modelling across senior debt, mezzanine, and equity tranches.

Financial Outputs and Metrics Comprehensive investment metrics including Project IRR, Equity IRR, NPV, DSCR, LLCR, WACC, MOIC, LCOE, and a full revenue breakdown by source.

Investment Committee-Ready Architecture Transparent, auditable model structure with clear separation between input assumptions, calculation engine, and output dashboard — built to professional financial modelling standards.

How to Work with this Model

Helios Nexum is structured using a layered architecture that separates inputs, energy simulation, financial calculations, and outputs into distinct, clearly labelled sheets. Users begin by entering project-specific technical and financial assumptions in the input layer. The energy simulation engine then generates hourly generation and dispatch profiles, which feed automatically into the financial engine. Outputs are presented in a structured dashboard covering operational metrics, financial returns, and capital structure.

The Pro Edition users can additionally connect to live data APIs to populate irradiance and market price inputs directly, significantly reducing setup time for new project scenarios.

Why do you need this model?

As hybrid solar + BESS projects become the dominant structure in renewable energy development, the analytical tools used to evaluate them must keep pace. A model that cannot simulate hourly dispatch behaviour, capture curtailment risk, or separate battery revenue from solar revenue will produce outputs that misrepresent project economics — with material consequences for investment decisions.

Helios Nexum gives analysts and investors the resolution, structure, and financial rigour needed to evaluate these assets accurately. Whether preparing a lender model, stress-testing scenarios for an investment committee, or benchmarking hybrid versus solar-only structures, Helios Nexum provides the analytical foundation to make informed, defensible decisions.

Requires Microsoft Excel 365 or Excel 2021. Macros must be enabled. No external software dependencies.

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