Solar Water Heater Calculator

Calculate the right solar water heater size for your household. Enter family size, daily usage, and climate zone to get recommended tank size, collector area, and energy savings.

๐ŸŒŠ Solar Water Heater Calculator

System Sizing

Daily Hot Water Need200 liters
Recommended Tank200 liters
Collector Area4 sq m
Solar Fraction70 %

Energy Savings

Daily Savings7.0 kWh
Annual Savings2,555 kWh

Financials

Estimated System Costโ‚น20,000
Annual Monetary Savingsโ‚น20,440
Payback Period1.0 years
ByPRIYA SHARMAโ€ขUpdated April 20, 2026
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Reviewed byDR. RAJIV NAIR
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Fact checked byNEHA KAPOOR

How Solar Water Heaters Work

Solar water heaters use flat plate collectors or evacuated tube collectors (ETC) to absorb sunlight and heat water stored in an insulated tank. They can provide 60โ€“85% of a household's hot water needs, dramatically reducing electricity or gas bills.

System Types

TypeEfficiencyCostBest For
Flat Plate (FPC)60โ€“70%โ‚น15,000โ€“โ‚น25,000 per 100LYear-round hot climate
Evacuated Tube (ETC)70โ€“85%โ‚น10,000โ€“โ‚น18,000 per 100LCold/cloudy climates

Sizing Guide

Family SizeDaily Hot WaterRecommended Tank
2 persons80โ€“100 liters100 liters
3โ€“4 persons150โ€“200 liters200 liters
5โ€“6 persons250โ€“300 liters300 liters
7โ€“8 persons350โ€“400 liters500 liters

Solar Water Heater Calculator FAQ