Debt Sizing Calculator — Renewable Energy Project Finance | Free Tool

Description
Stop recalculating the same debt sizing formula from scratch every time.
This free Excel calculator computes the maximum debt a renewable energy project can support while respecting a minimum DSCR covenant — in seconds. Works for Solar PV, Wind Onshore, Wind Offshore, BESS and any infrastructure project with a known EBITDA and loan structure.


Two sheets included:


Debt Sizing Calculator Enter your project inputs in the blue cells — CAPEX, EBITDA Year 1, EBITDA growth rate, interest rate, loan tenor, grace period, DSCR covenant and amortisation type (Annuity or Linear). The calculator outputs:

• Maximum debt from DSCR constraint (€M)
• Annual debt service post-grace (€M)
• Implied gearing (%)
• DSCR Year 1 check — with automatic warning if below covenant
• Grace period debt service (interest-only, €M)
• Equity required (€M)

A three-scenario comparison table (Conservative / Base / Aggressive gearing) shows DS, DSCR and feasibility for each structure. A full amortisation schedule preview covers Years 1 to tenor with opening debt, principal, interest, total DS, closing debt and DSCR per year.


How to Use Explains all input fields, the difference between Annuity and Linear amortisation, how to interpret DSCR, and the limitations of the tool vs a full sculpted debt model.


Objectives Calculate the maximum debt a renewable energy project can support given EBITDA and a DSCR covenant. Compare Conservative, Base and Aggressive gearing structures side by side. Preview the full annual debt service schedule without building a model from scratch.


Applies best when You are sizing debt for a solar PV, wind, offshore wind or BESS project and need a quick, accurate answer on maximum debt, gearing and annual debt service. Useful for early-stage project screening, lender conversations, investment committee presentations or sanity-checking a more detailed model.


Does not apply ideally when You need fully sculpted debt sizing with DSCR tested every year, minimum LLCR, DSRA modelling or cash sweep mechanisms. For complete 25-year project finance models with sculpted debt, three scenarios and multilingual PDF guides, see the paid models in this channel.