Mechanical · Energy and thermal · Final year project
Mini 20 Liter Solar Water Heater for Rooftop
A compact 20-litre rooftop solar water heater. Efficient copper coiling, heat-trapping insulation and reflecting mirrors heat water quickly using only sunlight.
What is the Mini 20 Liter Solar Water Heater for Rooftop project?
A compact 20-litre rooftop solar water heater. Efficient copper coiling, heat-trapping insulation and reflecting mirrors heat water quickly using only sunlight.
Key facts
- Type
- Final year project · Intermediate
- Suitable for
- Diploma capstone and B.E / B.Tech final year
- Build time
- 4 to 6 weeks
- Estimated component cost
- ₹6,800 – ₹10,000
- Guidance from
- ₹9,999 (Hardware / IoT Final Year)
How the Mini 20 Liter Solar Water Heater for Rooftop works
- The mild steel frame and fabrication forms the base that carries every other part, so it is designed first from the load and size of the machine.
- The Solar panel converts sunlight into electricity to power or charge the system.
- The Mini submersible water pump moves water for irrigation, dispensing or cooling.
Block diagram
Power
Mini submersible water pumpSolar panelCharge controller moduleStructure
Frame and mountsComponents list and cost
Typical prices from Indian online stores and electronics markets (Lamington Road, Budhwar Peth, SP Road). Buy from one store where you can to save on shipping.
| Component | Qty | What it does | Approx. cost |
|---|---|---|---|
| Mini submersible water pump (12 V) | 1 | Moves water for irrigation, dispensing or cooling. | ₹180 |
| LEDs (assorted) | 1 | Indicate status. | ₹20 |
| Solar panel (10–20 W) | 1 | Converts sunlight into electricity to power or charge the system. | ₹900 |
| Charge controller module | 1 | Charges the battery safely and stops overcharging. | ₹250 |
| Rechargeable battery (12 V 1.3–7 Ah) | 1 | Stores energy and supplies power when mains is absent. | ₹650 |
| Mild steel frame and fabrication | 1 | Forms the main structure that holds all parts. | ₹2,500 |
| Welding, cutting and machining labour | 1 | Needed for this type of build. | ₹2,200 |
| Mounts, screws, nuts and small hardware | 1 | Enclosure, mounts and fasteners. | ₹300 |
| Paint, finishing and workshop consumables | 1 | Project overhead | ₹600 |
| Transport of material | 1 | Project overhead | ₹400 |
| Estimated total | Varies with brand, quality and city | ₹6,800 – ₹10,000 |
Prices are estimates for budgeting. We confirm the bill of materials when your design is frozen, and components are charged at actual cost with bills.
How much does this project cost?
| Option | What you get | Cost |
|---|---|---|
| Components only | You buy the parts and build it yourself | ₹6,800 – ₹10,000 |
| Hardware / IoT Final Year | Working model or guided build, Circuit diagram and bill of materials, Firmware / code with explanation | from ₹9,999 + components |
| Capstone Project (CPE) | Working project or model, Black book in MSBTE format, Step-by-step explanation | ₹9,999 + components |
| Diploma ITR | 100% working source code, Project report PDF, PPT | ₹1,999 + components |
No GST and no hidden charges. Use the cost calculator for a quote with your deadline and add-ons, or see all plans.
Download the project brief (PDF)
Summary, working, components and cost and viva questions on one branded PDF to show your guide or team. To get it developed, contact us on WhatsApp.
What you submit with this project
- Working model with circuit diagram and program code
- Project report or black book in your university's chapter order (block diagram, circuit, calculations, results)
- Presentation for the review and final viva
- Synopsis for topic approval, if your college asks for one
Mechanical viva questions on this project
What is the aim of the Mini 20 Liter Solar Water Heater for Rooftop project?
A compact 20-litre rooftop solar water heater. Efficient copper coiling, heat-trapping insulation and reflecting mirrors heat water quickly using only sunlight.
Explain the working of your project in short.
The mild steel frame and fabrication forms the base that carries every other part, so it is designed first from the load and size of the machine. The Solar panel converts sunlight into electricity to power or charge the system. The Mini submersible water pump moves water for irrigation, dispensing or cooling.
How is the pump switched by the controller?
Through a relay or MOSFET, because the pump runs at 12 V and draws more current than the controller pin can provide.
Why is a resistor connected in series with an LED?
It limits the current to a safe value (about 10–20 mA). Without it, the LED would draw too much current and burn out. R = (supply voltage − LED voltage) ÷ current.
What is the efficiency of a typical solar panel?
Commercial polycrystalline panels convert about 15–17% and monocrystalline about 18–22% of sunlight into electricity. Output depends on sunlight, angle and temperature.
Why is a charge controller needed?
It regulates the charging voltage and current, cuts off when the battery is full and prevents deep discharge, which protects battery life.
How do you calculate battery backup time?
Backup time (hours) ≈ battery capacity (Ah) × voltage × 0.8 efficiency ÷ load power (W). For example, 12 V 7 Ah at 20 W gives about 3.3 hours.
Which material did you select for the main parts and why?
Mild steel (MS) is used for the frame because it is strong, cheap, easy to cut and weld and available everywhere. Shafts are made of EN8 or bright mild steel for strength, and parts that do not carry load can be aluminium or acrylic to reduce weight.
What factor of safety did you take in your design?
A factor of safety of 2 to 3 is taken for static parts and 3 to 5 for parts under shock or fatigue loading. Allowable stress = yield strength ÷ factor of safety, and each part is checked against it.
How did you estimate the cost of the project?
The cost is the sum of raw material, bought-out parts, machining or fabrication and overheads. Our estimate for this model is about ₹6,800 to ₹10,000, depending on size, material and the workshop rates in your city.
Which manufacturing processes were used?
Cutting and grinding of sections, arc or MIG welding of the frame, drilling for mounting holes, followed by assembly, alignment and painting.
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Want to build Mini 20 Liter Solar Water Heater for Rooftop?
Send your college, deadline and team size. We confirm the scope, cost and what you will submit.