Solar · Excel workbook
Solar Rooftop Generation and Savings Calculator
Compare estimated generation, self-consumption, exports and simple payback.
Download free XLSX ↗Version 1.0 · 25 September 2026 · No registration required
What you need
- DC capacity in kWp
- Peak-sun-hours equivalent and performance factor
- Self-consumption share
- Import and export value in INR per kWh
- Capital cost, annual O&M and grid emission factor
What you get
- Indicative annual generation
- Annual net operating savings
- Simple payback and indicative avoided grid emissions
How to use it
- Save a working copy and read the instructions in the file.
- Replace illustrative inputs or response fields with your site records.
- Check units, dates and boundaries before using the results.
- Keep the completed file with its supporting evidence.
Method
Generation = capacity × equivalent sun hours per day × 365 × performance factor. Savings value self-consumed and exported energy separately and subtract annual O&M.
Scope and limitations
Illustrative inputs are not quotations, local irradiation data or tariff advice. No subsidy, financing, tax, degradation or replacement is included in simple payback. Avoided grid emissions are not full lifecycle carbon savings.
Reference: DOE PV monitoring guidance
Read the related guide: Practical guidance for this tool.