Total Solar System Design | Based on Combined Motor Load
View Full Design
Enter your details to continue
Solar VFD, ROI & Multi Motor Solar Calculator for Industry & Agriculture
Solar Calculator Pro is India's most comprehensive industrial solar sizing tool. Design solar VFD systems for agriculture pumps, cold storage units, rice mills, atta chakki, and multi-motor factories. Get instant string design, panel counts, ROI analysis, and proposal-grade PDF reports — completely free.
⚡ Solar VFD Calculator
Precisely size solar VFDs for 1-phase and 3-phase motors. Enter HP, current & RPM — get instant VFD rating, panel count, string design, and DC voltage range.
☀️ Solar ROI Calculator
30-year cashflow model with panel degradation, tariff escalation, and maintenance. See exact payback year, cumulative profit, and annual savings.
🔧 Multi Motor Solar Calculator
India's first multi-motor solar VFD calculator. Group motors by phase and RPM, get separate VFD and panel design for each group — ideal for factories and cold storage.
📄 Proposal PDF Export
Generate client-ready solar design reports with system summary, string design, motor breakdown, and 30-year financial analysis — all in one click.
Industry Solar Calculator Applications
❄️
Cold Storage Solar
Size multi-motor solar VFD systems for cold storage compressors and cooling units. Reduce electricity bills by 80–100%.
🌾
Rice Mill Solar Design
Solar VFD systems for rice hullers, polishers, and blowers. Calculate exact panel count for each motor separately.
🌀
Atta Chakki Solar
Solar-powered atta chakki systems. Single-phase and three-phase VFD sizing for flour mills of all capacities.
💧
Agriculture Solar Pump
Solar VFD for bore wells and irrigation motors. 1 HP to 150 HP, single and three phase. Full string design included.
🏭
Factory Multi Motor Solar
Design solar systems for 2–10 motors running simultaneously. Grouped by phase and RPM for optimal VFD selection.
How Solar VFD Sizing Works
1
Read Motor Nameplate
Note HP (or kW), full load current (Amps), RPM, voltage, and phase from your motor's nameplate plate. Current accuracy directly affects VFD and panel sizing.
2
Why RPM Matters
Same HP motor at 960 RPM draws more current than at 1440 RPM. A 5 HP motor at 1440 RPM draws ~7.4A while the same motor at 960 RPM may draw ~7.7A. RPM selection improves VFD accuracy.
3
Single vs Three Phase
Single-phase VFDs are available up to 5 HP (16A max). For higher loads, three-phase solar VFDs are required. Three-phase motors also offer better efficiency and longer life under solar VFD operation.
4
String & Panel Design
Solar VFDs need a minimum DC voltage range (typically 500–900V). Panel strings are sized to deliver this voltage. Fewer strings are preferred to reduce wiring cost while maintaining safe operating current.
Frequently Asked Questions
How many solar panels are needed for a 5 HP solar VFD motor?
A 5 HP three-phase motor at 1440 RPM typically draws 7.4–8.8A. Using 550W panels with 1 string of 16 panels (8.8 kW), this comfortably powers a 5 HP solar VFD system. The 725W panel option uses 1 string of 17 panels (12.3 kW) for higher headroom. Use the VFD Calculator above to get the exact recommendation based on your motor's nameplate current.
What is the difference between a solar pump calculator and a solar VFD calculator?
A solar pump calculator typically estimates system size based on daily water output. A solar VFD calculator sizes the Variable Frequency Drive and solar panels based on the actual motor current, HP, and RPM — giving a more accurate electrical design. This calculator uses real motor performance data to validate your inputs and recommend the correct VFD rating and panel configuration.
How does the multi motor solar calculator work?
The Multi Motor Solar Calculator groups your motors by phase and RPM. Motors of the same phase and RPM share a single VFD (if they run one at a time). Different phase or RPM groups get separate VFDs. The calculator shows the panel count, string design, and total solar capacity needed for your entire multi-motor system — ideal for rice mills, cold storage, and factories.
What is solar ROI and how long is the payback period?
Solar ROI measures 30-year net profit as a percentage of your initial investment. Most industrial and agricultural solar VFD systems achieve payback in 3–7 years and total ROI of 200–500% over 30 years. The calculator uses a proper cashflow model with 4% annual tariff escalation, 0.5% panel degradation, and 3% maintenance cost escalation — giving you a realistic financial picture.
Can one solar VFD run multiple motors?
A three-phase solar VFD can drive multiple motors of the same type and RPM if they operate one at a time (sequential operation). For simultaneous operation, each motor needs its own VFD. Single-phase motors always require dedicated VFDs — single-phase current cannot be shared. This calculator correctly handles both cases in the Multi Motor tab.
How to calculate solar VFD size for a rice mill or cold storage?
List all motors in your rice mill or cold storage: HP, current (from nameplate), RPM, and phase. Enter each motor in the Multi Motor Calculator. The tool groups same-phase, same-RPM motors under one VFD and calculates the total solar panel requirement. For cold storage with multiple compressors, each compressor group gets its own VFD calculation with separate string design.