🔧 Option 1: Basic Solar Thermal + Radiator (Water System)
This is the most practical and efficient low-cost setup.
🧱 Materials (easy to find locally)
- Black-painted metal sheet (old iron sheets work well)
- Clear plastic sheet or glass (for trapping heat)
- PVC or PPR pipes
- 20–50L plastic jerrycan or tank
- Small radiator (e.g., from an old car or motorcycle)
- Rubber hoses
- Hose clamps
- Wooden frame or metal stand
- Optional: small 12V pump (or go pump-free)
⚙️ How it works (simple idea)
Sun heats panel → water warms up → hot water flows → radiator releases heat → cooled water returns
🏗️ Step-by-step design
1. Build the solar collector (heat absorber)
- Take a flat surface (wood/metal frame)
- Fix a black-painted iron sheet (absorbs heat best)
- Lay a pipe in a zigzag pattern over/under the sheet
- Cover with clear plastic or glass (creates greenhouse effect)
👉 This becomes your solar heat collector
2. Set up the water tank (storage)
- Place a jerrycan slightly above the panel
- This allows natural circulation (thermosiphon)—no pump needed
3. Connect pipes
- Cold water flows from bottom of tank → panel
- Heated water rises from panel → top of tank
4. Add the radiator (heat delivery)
- Connect outlet from tank → radiator → back to tank
- Place radiator where you want heat (room, dryer, etc.)
🔁 Two flow options
Option A: No pump (cheapest)
- Uses natural convection
- Works best if:
- Tank is higher than panel
- Pipes are short and well-aligned
Option B: With small pump
- Use a 12V pump powered by a small solar panel
- Better control and stronger heat flow
🔥 What you can use it for
- Room heating (small spaces)
- Drying agricultural products (coffee, maize, fish)
- Pre-heating water for domestic use
