Engineering Calculators
A free toolbox of power distribution and solar engineering calculators. Enter your values and get a sized component, a reference price and a worked calculation in seconds — each tool links to the matching QDTB product line.
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⚡ Power System Configurator — Build & Price Online
Design a complete power system in 4 steps: power sources, distribution, transformer and protections. Instant BOM, drawings and price.
Design Your System in Minutes
Pick a scenario and build your power system in four steps — single-line diagram, calculation sheets, construction drawings and FOB pricing, all generated automatically.
Grid-Side Storage500 kW PCS · 35 kV step-up · 2 MWh/4 h BESS · grid-formingDesign this system 
C&I Storage500 kW PCS · 10 kV/0.4 kV · 2 MWh/4 h BESS · arbitrageDesign this system 
Source-Grid-Load-StoragePV 1000 kWp · BESS 800 kW/1600 kWh · Diesel 600 kW · on/off-gridDesign this system 
Long-Duration Storage2000 kW PCS · 8 h/16 MWh LDES · 2×S13-M-2000/35 N+1Design this system 
Green Hydrogen2×SCB13-4000/35 N+1 · APF 4055 A + SVG ±1 Mvar + PFCDesign this system Cascade StorageYB-500/10 prefab cabin · 500 kW PCS · 1000 kWh second-lifeDesign this system 
Off-Grid MicrogridPV 800 kWp · BESS 600 kW/1200 kWh · Diesel 500 kW · black startDesign this system 
Hospital2× SCB13-400/10 N+1 · 500 kVA diesel · 200 kVA/15 min UPS · medical IT isolationDesign this system 
Smart Manufacturing10 kV feed · 2×500 kVA N+1 · 90 kW VFD motor · 152 kvar detuned PFCDesign this system 
Petrochemical2×S13-M-800/10 N+1 · 200 kW ESP VFD · Ex Zone 2 · 1000 kVA dieselDesign this system 
Port Terminal2×S13-M-630/10 N+1 · 160 kW crane VFD · SVG dynamic compensationDesign this system 
Mining2×S13-M-630/10 N+1 · 250 kW hoist VFD · SVG · 500 kW dieselDesign this system 
Airport2×SCB13-500/10 N+1 · 400 kW diesel · 150 kVA UPS · 400 Hz GPU bridgeDesign this system 
Water Pumping Station2×S13-M-315/10 N+1 · 132 kW pump VFD · 75 kvar PFCDesign this system 
Commercial ComplexS13-M-400/10 · 100 kvar PFC · 200 kW diesel fire backupDesign this system 
Office Building380 V LV switchgear · 80 kVA online UPS · 80 kW standby dieselDesign this system 
AI Data Center + Green2×SCB13-2000/10 N+1 · 800 kVA UPS · 1000 kWp PV + 500 kW BESSDesign this system 
Home Solar5 kWp PV · 5 kW/10 kWh home BESS · 220 V single-phaseDesign this system 
Onshore Wind500 kW WTG · 800 kVA box transformer · 35 kV collector · 110 kV step-upDesign this system 
Utility-Scale PV Base910×550 Wp · 2×250 kW string inverters · 630 kVA box substationDesign this system 
Offshore Wind500 kW WTG · 800 kVA box · offshore GIS · 110 kV submarine cableDesign this system 
BIPV BuildingBIPV 200 kWp · BESS 150 kW/300 kWh · SCB13-400/10Design this system 
Rooftop PV800 kWp PV · 0.4 kV grid connection · anti-islanding · net meteringDesign this system 
Biomass Power500 kW synchronous genset · S13-M-500/10 step-up · 80 kW house loadDesign this system 
How to use these calculators
- 1. Pick a tool below. Each calculator is a self-contained page with its own inputs, formulas and worked example.
- 2. Enter your load, voltage, material or site values. Defaults are sensible — change only what you need.
- 3. Read the result: a recommended size or model, the step-by-step calculation, and a reference FOB price where pricing applies.
- 4. Copy the result link to share a specific configuration, or embed the tool on your own site.
All tools
30 free power engineering calculators
System-level design calculators
Distribution System CalculatorComplete LV/MV distribution design: transformer sizing, HV/LV switchgear, cables, grounding and protection — IEC/NEC/GB compliant, with BOM and FOB pricing.BOMSLDPriceView details PV Plant + Grid Interconnection CalculatorUtility-scale PV plant + grid interconnection: voltage level, main transformer, collector system, reactive power and substation BOM.BOMSLDPriceP50/P90View details Solar System ConfiguratorSize the PV array, inverter, battery and cables for residential or C&I solar — with map-based solar resource, P50/P75/P90 probability yield, and full-cost economics (LCOE, payback, IRR, NPV).BOMPriceP50/P90View details