Solar Design & Sizing Tools

Free online calculators calibrated for Kenyan conditions, plus links to professional solar power design software.

For Systems < 50 kW
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Off-Grid Express System Sizer

The fastest way to size your system. Just enter your monthly KPLC 'Units' and we instantly calculate your solar panel, battery, and inverter requirements.

Start Sizing
Sizer, auditor, cost estimator
🔍

Sizer, Auditor and Cost Analyser

List your appliances to see what's eating your electricity. Find ways to cut your power bill as you calculate the optimum solar power system. Estimate system cost and return on investment.

Start Detailed Analysis
Solar Thermal
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Solar Water Heater Sizer

Stop using expensive electricity to heat water. Tell us your daily hot water needs, and we'll calculate the exact solar thermal setup required.

Size Heater

Off-Grid Express Sizer

Quickly calculate your solar requirements based on your monthly KPLC bill.

System Parameters

Sizing Results

Location Sun Hours
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Avg Temp (°C)
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Required Solar Panels
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(e.g., 2 x 400W)
Battery Bank Capacity
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(Ah @ 24V)
Minimum Inverter Size
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(kVA - Handles surges)
💡 Pro Tip: Always round up your inverter size by at least 20% above your total solar panel wattage to handle startup surges from fridges and water pumps without tripping.

Recommended Professional Software

Tools for detailed shading analysis, 3D modeling, and financial yield predictions.

COMMERCIAL

PVSyst

The undisputed industry standard for detailed PV system design, loss analysis, and bankable energy yield simulations.

Visit PVSyst >
FREE & OPEN SOURCE

System Advisor Model (SAM)

Developed by the US National Renewable Energy Lab (NREL). Incredible for detailed financial modeling, grid-tied analysis, and battery dispatch simulations.

Download SAM >
FREE TIER

OpenSolar

A modern, cloud-based platform. Excellent for fast residential/commercial quoting, 3D roof mapping, and generating beautiful client proposals in minutes.

Try OpenSolar >
FREE TIER

PV*SOL (Valentin Software)

The free version of PV*SOL is fully capable of designing systems up to 100kW. Great 3D shading engine and detailed hourly simulation.

Download Free Version >
COMMERCIAL

HOMER Grid / Pro

The ultimate tool for optimizing hybrid microgrids, grid-tied solar plus storage, and complex off-grid systems with generators.

Visit HOMER >
FREE TIER

SketchUp + Skelion

Use the free version of SketchUp for 3D rooftop modeling, and install the Skelion plugin for automated panel layouts, shading, and string sizing.

Get Skelion Plugin >