COMPARISON
Excel is the historical tool of project finance — and it does the job to get started. The real question is not “can Excel do it?” but “what does reliability cost once the project must be bankable?”. An honest comparison, criterion by criterion.
| Criterion | Excel spreadsheet | Wattvalio |
|---|---|---|
| Learning curve | Immediate — everyone knows Excel | Guided tabs (generation → sales → debt → results) |
| Modelling flexibility | Total: any formula, anywhere | Structured assumptions with project-finance conventions built in |
| Formula-error risk | Real and silent (one shifted reference corrupts the whole model without warning) | Single calculation engine, locked by automated non-regression tests |
| Scenarios & versions | File duplication ("BP_final_v3_REAL.xlsx") — silent divergence | Isolated versions per project: duplicate, compare, lock, archive |
| Traceability (who changed what) | None natively; workbook history stays partial | Field-level audit trail: old value → new value, author, date |
| P50 / P90 generation | Hand-built, rarely propagated everywhere | Native across the chain: revenues, lender DSCR, exports |
| Actuals vs budget | Re-typed into new tabs, manual reconciliation | Dedicated tab (entry + import), variances per metric × year, reforecast anchored on actuals |
| Lender package | Manual formatting at every iteration | One-click P50/P90 export with banking conventions (annual flows, year-end stocks) |
| Consolidated portfolio | Fragile linked workbooks (broken links, out-of-sync versions) | Native holdings/SPVs: ownership, dividends, shareholder loans, NAV/SOTP |
| Collaboration & access rights | Shared or e-mailed file — who has the right version? | Multi-user, per-project roles, per-organisation isolation |
| Data security | Depends on individual discipline (local files, attachments) | EU hosting, multi-tenant isolation at database level (row-level security) |
| Cost | Office licence already in place | SaaS subscription (access by invitation) |
A reference shifted by one row, an inverted sign, a frozen range that no longer covers the new columns: the workbook keeps displaying numbers — wrong ones. In due diligence, the analyst across the table is the one who finds them. Wattvalio has a single calculation engine covered by non-regression tests: any drift in IRR, NPV or DSCR blocks the release before it reaches your figures.
BP_v3_final_REAL_2.xlsx: every scenario is a file, every file diverges, and nobody knows which one went to the investment committee. In Wattvalio, each version is isolated (its assumptions never affect the others), comparable, lockable and archivable — with a journal of who changed what, when, from which value to which value.
Linked workbooks break at the first rename and drift out of sync silently. The Wattvalio portfolio is native: per-SPV ownership, dividend up-streaming, shareholder loans, NAV/SOTP valuation and valuation bridge — recomputed together on every change.
Comparing budget to actuals means new tabs and manual reconciliation. Wattvalio has an Actuals tab (entry or xlsx/csv import), variances per metric and per year using banking conventions, and a reforecast anchored on actuals: the past displayed as booked, the future recomputed from the real cash position and debt outstanding.
You keep them. Wattvalio exports to Excel — P50/P90 lender package, full business plan, investor pack — and imports your accounting actuals from a template. The spreadsheet stays the exchange format with your banks and investors; it simply stops being your calculation engine.
For the full method, see the solar & photovoltaic business plan guide, the bankable financing dossier and the solar business plan software.
Yes — Excel remains the historical tool of project finance, and a well-built model can be bankable. The real question is the cost of reliability over time: every iteration, scenario and additional asset multiplies the risk of a silent formula error, and due diligence requires justifying every figure. That reliability work is what dedicated software industrialises.
To prototype an idea in an hour, for a one-off ad hoc analysis that will never be replayed, or when the model is mastered end-to-end by one person who never has to hand it over. As soon as there are several scenarios, several assets, several reviewers or a bank across the table, the spreadsheet becomes the weakest link.
No. Wattvalio exports to Excel (P50/P90 lender package, full business plan, investor pack) and imports accounting actuals from an xlsx/csv template. The spreadsheet stays your exchange format; it simply stops being your calculation engine.
The calculation engine is unique and covered by hundreds of automated tests, including a locked set of reference values: any drift in an indicator (IRR, NPV, DSCR, LCOE) fails the release before it reaches your numbers. Every changed assumption is journaled, and every result unrolls line by line in the Computations tab.
Bring your Excel model — we replay it in Wattvalio with you.