Solar PV System Design & Financial Analysis Excel Calculator

A professional, fully functional Microsoft Excel workbook designed for solar installers, EPC companies, electrical engineers, renewable-energy consultants, and solar businesses.

This advanced solar PV design tool combines engineering calculations, equipment sizing, project costing, financial analysis, dashboards, and client-ready proposal generation in one structured Excel workbook.

Key Features

Solar PV System Design

• Automatic PV array sizing

• Required and recommended PV capacity

• PV module quantity and installed capacity

• PV string and parallel-string calculations

• Peak Sun Hours and system-loss calculations

• Design margin and degradation assumptions

• PV voltage/current validation

Battery Bank Sizing

• Battery capacity calculations

• Required usable and nominal energy

• Battery capacity in Ah and kWh

• Series and parallel battery configuration

• Battery quantity and bank voltage

• Depth-of-discharge and efficiency calculations

• Support for lithium/LFP and lead-acid assumptions

• Battery configuration warnings

Inverter Sizing

• Continuous load calculation

• Peak/surge demand calculation

• Minimum inverter rating

• Recommended inverter size

• Surge-rating requirements

• Undersized inverter warnings

Charge Controller Sizing

• MPPT/PWM controller support

• PV charging current calculations

• Recommended controller rating

• Controller quantity calculations

• PV voltage and current checks

• Excessive charging-current warnings

Detailed Load Schedule
Enter appliances and electrical loads with:

• Appliance name

• Category

• Quantity

• Rated power

• Operating hours

• Duty cycle

• Starting/surge power

• Day/night usage

• Notes

The workbook automatically calculates:

• Connected load

• Continuous load

• Peak demand

• Daily energy consumption

• Day/night energy consumption

• Total Wh/day and kWh/day

Three Solar System Scenarios

Off-Grid

• PV array

• Battery bank

• Inverter

• Charge controller

• Autonomy calculation

• Generator/backup option

Grid-Tied

• PV generation

• Grid consumption

• Self-consumption

• Exported energy

• Grid imports

• Electricity tariffs

• Solar savings

Hybrid

• PV + battery + grid

• Critical/backup loads

• Battery charging/discharging

• Grid import/export

• Self-consumption analysis

Cable Sizing Calculator

Includes calculations for major DC and AC circuits using:

• Voltage

• Current

• Cable length

• Conductor material

• Cable size

• Allowable voltage drop

• Design factor

Automatically calculates voltage drop, voltage-drop percentage, minimum conductor size, and recommended cable size.

Equipment & BOM

Create a complete project Bill of Materials including:

• PV modules

• Inverters

• Batteries

• Charge controllers

• Mounting structures

• Protection equipment

• Combiner boxes

• Disconnects

• Cables and connectors

• Earthing equipment

• Monitoring equipment

• Installation materials

• Labor

• Engineering/design costs

Automatic quantity, unit-price, subtotal, and total CAPEX calculations are included.

Financial Analysis

Analyze the economic performance of a solar project over up to 25 years, including:

• CAPEX

• O&M costs

• Electricity tariffs

• Tariff escalation

• PV degradation

• Battery replacement

• Inverter replacement

• Financing costs

• Annual energy generation

• Self-consumption

• Export revenue

• Annual savings

• Cash flow

• Simple payback

• Discounted payback

• ROI

• NPV

• IRR

• Lifetime savings

• Lifetime costs

Professional Dashboard

A management dashboard presents key project results including:

• PV capacity

• Battery capacity

• Inverter capacity

• Daily energy demand

• Peak load

• Annual PV generation

• CAPEX

• Annual savings

• Payback period

• ROI

• NPV

• Lifetime savings

Includes professional charts for energy generation, consumption, cash flow, cumulative cash flow, energy sources, and component sizing.

Client Proposal

Generate a printable client-facing proposal using automatically linked project calculations.

The proposal includes:

• Client/project information

• Proposed system type

• PV capacity

• Number of panels

• Battery capacity

• Inverter size

• Estimated annual generation

• Estimated annual savings

• Project cost

• Payback period

• ROI

• Key equipment

• Major assumptions

• Design notes

• Professional disclaimer

Workbook Includes

1. Cover & Instructions

2. Project Information

3. Load Schedule

4. Design Assumptions

5. Solar Resource

6. Off-Grid Design

7. Grid-Tied Design

8. Hybrid Design

9. Equipment & BOM

10. Financial Analysis

11. Dashboard

12. Client Proposal

Built for Professional Use

The workbook emphasizes:

• Automatic Excel formulas

• Transparent engineering calculations

• Auditable design relationships

• Input/calculation cell separation

• Data validation

• Dropdown selections

• Conditional formatting

• Engineering warnings

• Professional formatting

• Printable reports

• Client-ready presentation

Important Disclaimer

This workbook is intended as a design, sizing, estimation, and planning tool. It is not a substitute for professional engineering review. Final equipment selection, electrical protection, cable sizing, structural design, installation, safety, and regulatory compliance must be verified by a qualified professional against applicable local codes, standards, installation conditions, and manufacturer specifications.

Ideal For

• Solar installation companies

• EPC contractors

• Solar PV engineers

• Electrical engineers

• Renewable-energy consultants

• Solar sales professionals

• Freelance solar designers

• Engineering students and educators

• Client proposal preparation

• Preliminary solar feasibility studies

A complete solar PV engineering, costing, financial-analysis, and proposal solution inside Microsoft Excel.