Solar calculator

How much solar do you need?

Adjust the inputs and watch the house update. You get an estimate of panels, inverter, battery and savings — then send it to our engineers for a firm design and quote.

The calculator needs JavaScript. You can still request a quote and an engineer will size the system for you.

1 Property

Property type

Home Business

Location

Sets the average sunshine used in the estimate.

2 Electricity use

Monthly bill (KES) Monthly units (kWh)

Average monthly KPLC bill

KES

3 System

System type

Grid-tiedCuts daytime bills. No backup during outages. HybridSolar + battery + KPLC. Backup during outages and solar power after dark. Off-gridNo KPLC connection. Solar and battery supply everything.

Share of your electricity to cover with solar

80%

During an outage, keep running

Backup hours needed

6 h

4 Hot water (optional)

Add a solar water heater

+ Advanced settings

Electricity cost per kWh (KES)

Default is an approximate all-in KPLC domestic rate (June 2026). Check your bill.

Electricity supply

Panel model

Usable roof area (m²)

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Your estimated system

Solar array–

Inverter–

Battery storage–

Estimated savings–

Recommended products

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How we calculate this

This is an estimate to help you plan, not a quotation. We size the solar array from your monthly consumption and the average daily sunshine for your location (Annual average global horizontal irradiation, kWh/m²/day (NASA POWER climatology via peaksunhours.app, accessed Oct 2026).). We apply a 77% performance ratio for real-world losses.

Batteries are sized for the larger of your evening use or the backup you ask for, at 90% usable depth of discharge. The inverter is sized for your estimated peak load and array size.

Approximate all-in KPLC domestic cost per kWh above 100 kWh/month incl. fuel cost, forex, levies and 16% VAT (June 2026 rates). Pass-through charges change monthly; users can enter their own figure.

Savings assume solar replaces grid electricity at your tariff. Grid-tied savings count daytime use only. Final sizing depends on your roof, shading, wiring and appliances, which we confirm during a site assessment. Assumptions version 2026-10-05.