Domestic solar water heaters are seen as one of the most cost effective renewable energy options in many parts of the world.
Solar water heating systems cost more to purchase and install than conventional water heating systems. However, a solar water heater can usually save you money in the long run. This depends on many factors such as the initial cost of the system, solar radiation and the cost of fuel/ electricity.
Try out our tool for to estimate the feasibility of installing a domestic solar water heating system.
NOTES:* Denotes a recommended value Numbers in brackets are negative
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Conversion of Units
Assumptions About The Solar Heating System
You can make changes that you deem necessary
Flat Plate Solar Collectors are widely used in domestic water heating installations. Evacuated tube collectors are more expensive and typically used in larger, commercial applications due to their higher efficiency.
It is the total size of the surface of the solar collector that faces the sun.
The area over which the solar radiation enters the collector.
How much sun's energy can the solar collectors convert into heat. In other words, what comes out of the collectors.
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General Information
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It is widely accepted that the value of money today is greater than its value in the future. This means that money received at a later time is not as valuable as the same amount received today. This concept is not related to inflation, hence even if inflation is zero, we would still prefer to receive money today than the same amount of money after some time. This is primarily because we can put the money to use today in various ways such as learning a new skill, purchasing a laptop for work, or investing the money to watch it grow.
This tool helps in calculating the present value of future cash flows. The discount rate determines the value of future benefits; a higher discount rate implies that the value of benefits decreases with time. Simply speaking, you may use the interest rate offered by commercial banks on deposits as the discount rate. If you don't want to discount future cash flows, you can set the discount rate to zero.
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Domestic Hot Water (DHW)
The tool allows for a temperature up to 70 °C.
Solar Water Heating
The portion of the total heating load delivered by solar energy.
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Construction & Operation Costs
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Loan Details
If you are not taking a loan to finance this project, set the fields below to zero.
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Savings
Results
Domestic Hot Water (DHW)
Needed daily hot water (gallons)
Needed daily hot water (kg)
Required Energy - Typical Heater
Temperature difference (°C)
Energy required to raise temperature (kWh)
Solar Water Heating
Average hot water from solar (kg)
Heat required to raise temperature (kWh)
Solar Heating - System Size
Number of solar collectors
So, actual aperture area in m²
Solar collectors' gross area in m²
Savings
Compared to heating same amount of water using electric heater(s)
Daily energy savings (kWh)
First year energy savings (kWh)
First year energy savings ()
Runningn Costs
First year maintenance cost
Loan yearly payment
Investment Breakdown
Solar system cost
Initial Investment
Loan principal payment
Interest
Opex
Should I Just Save My Money?
Assuming the interest rate is equivalent to the discount rate
