Free solar & BESS engineering calculators — 20 tools, no signup.
System sizing, financial analysis, site layout and electrical design — the same formulas our engineering team uses for early-stage feasibility.
Formula-based engineering estimates from GALILEO's own design benchmarks, with live NREL PVWatts irradiance where noted — not a live component database. For a bankable, site-specific study, request a formal brief.
System Sizing & Production
Size a PV system from your bill, consumption or rooftop area, with live NREL irradiance and a real panel picker.
Build your daily and monthly kWh consumption from an appliance checklist.
Forecast annual and monthly yield with a 25-year degradation projection.
Size DC- or AC-coupled BESS with a real battery catalog and one-line schematic.
Calculate Performance Ratio from actual generation vs reference yield.
Financial Analysis
Simple and discounted payback period, plus lifetime ROI.
Levelized Cost of Energy with a discounted cash-flow model.
Compare cash purchase, loan EMI and a PPA-equivalent cost.
Estimate savings from export credits and self-consumption.
CO2 offset and equivalent trees planted from your annual generation.
Site & Layout Design
Ground Coverage Ratio, row pitch and land use per kWp.
Minimum row spacing to avoid winter-solstice inter-row shading.
Optimal fixed tilt for your latitude and seasonal bias.
Total field area from module specs, layout and GCR.
Peak sun hours and annual irradiation for any location, live from NREL.
Pre-screen mounting types against wind-load codes.
Electrical Design & Sizing
Optimize inverter loading ratio (ILR) and flag clipping risk.
Match inverter capacity to array size with DC:AC compliance.
Temperature-corrected Voc and MPPT window validation.
Check DC and AC voltage drop against guidance limits.
Size DC cables with full IEC ampacity and derating tables.
LV/HV AC cable sizing with K-factor derating.
Size MCB/MCCB/ACB protection devices.
Prospective fault current for protection coordination.
Comparison Tools
Earthing & Protection
Size DC earthing conductors and pits.
Size AC-side earthing and grounding systems.
Calculate lightning protection zones for PV plants.
EV Charging
Size combined solar and EV charging systems.
Electrical load calculator for multi-charger hubs.