Loading calculation engine...
Loading calculation engine...
Calculate annual electricity savings, capital payback period (years), and 10-year ROI for 100L to 200L Solar Water Heaters and Heat Pumps vs Electric Geysers.
Upgrading from electric geysers to a 100L Solar Water Heater Benchmark (ETC 85% Solar) pays back its extra capital investment of ₹10,000 in 1.2 Years, yielding ₹73,514 in net savings over 10 years!
Calculate standing losses and monthly power consumption for electric water heaters.
Calculate rooftop solar PV net-metering ROI and electricity bill elimination.
Convert Joules to kWh and calculate thermal water heating requirements.
Thermal water heating energy is calculated using specific heat capacity ($Q = m c \Delta T$), then comparing electric geysers (90% thermal efficiency + standing losses) against solar ETC systems (85% solar fraction) and heat pumps (COP 3.6).
| System Technology | Capital Cost | Annual kWh Draw (100L/day) | Annual Power Bill (₹7.50/unit) | Simple Payback Period |
|---|---|---|---|---|
| 100L Solar ETC Heater | ₹28,000 | 259 kWh / yr | ₹1,940 / year | 0.91 Years (~11 Months) |
| 200L Solar ETC Heater | ₹42,000 | 517 kWh / yr | ₹3,881 / year | 1.09 Years |
| 150L Air Heat Pump (COP 3.6) | ₹75,000 | 427 kWh / yr | ₹3,202 / year | 5.85 Years |
| Conventional Electric Geyser | ₹18,000 | 1,725 kWh / yr | ₹12,937 / year | Baseline (0 Savings) |
A 100-Litre Solar Water Heater (ETC system) costing ~₹28,000 pays for itself in less than 1 to 2 years for an average family using 100L hot water daily, by saving ~₹11,000 per year in electric geyser power bills.
Evacuated Tube Collector (ETC) solar water heaters absorb diffuse solar radiation and retain water temperature well on overcast days. During heavy monsoon rain, built-in electrical backup heating elements supply supplementary heat (~15% annual grid backup).
Solar Water Heaters use free sunlight from rooftop collectors (85% energy savings). Air-Source Heat Pumps extract heat from ambient air using a refrigeration cycle (COP 3.6, 75% energy savings), operating 24/7 rain or shine without needing direct sunlight.
Yes. Evacuated Tube Collector (ETC) systems are tested under BIS IS 16542, while Flat Plate Collector (FPC) systems follow BIS IS 12933 standards under MNRE guidelines.
Calculate monthly electricity units and power bill for 10L, 15L, and 25L storage geysers.
Compare running costs between LPG gas geysers and electric storage water heaters.
Calculate rooftop solar PV payback period, net-metering credits, and PM Surya Ghar subsidies.