Rooftop Solar ROI Calculator
DIY Rooftop Solar ROI Calculator: Track Payback Period with ESP8266 & INA219
Every part needed, pre-tested for compatibility, with an AI build companion trained on this exact project. Shipped from Bengaluru in 3-5 days.
Build a self-contained IoT device that measures real‑time solar energy generation using dual INA219 sensors, logs daily kWh to an SD card, and calculates the exact payback period against your rooftop installation cost. Ideal for validating solar economics before scaling up to a full residential system.
What You'll Build
A waterproof, ESP8266‑powered monitor with an OLED display showing instantaneous power (W), accumulated energy (kWh), and estimated days to break even. The device stores months of timestamped data for spreadsheet analysis, letting you see seasonal generation trends and adjust your payback projections.
What You'll Learn
- Dual‑channel current and voltage sensing with INA219 over I2C multiplexing
- Long‑term data logging using DS3231 RTC and MicroSD storage
- Wireless data serving via ESP8266 web server for local monitoring
- Implementing a payback algorithm that factors in installation cost, electricity tariff, and daily generation
Kit Contents
| Component | Quantity |
|---|---|
| ESP8266 NodeMCU | 1 |
| INA219 | 2 |
| Solar Panel 6V 2W | 1 |
| DS3231 RTC | 1 |
| MicroSD Module | 1 |
| TCA9548A I2C Mux | 1 |
| 0.96in OLED | 1 |
| 4.7kΩ Resistors | 5 |
| 100nF Capacitors | 5 |
| PCB Prototype Board | 2 |
| Waterproof Enclosure | 1 |
| Soldering Iron | 1 |
| Solder Wire | 1 |
Why Buy This Kit Instead of Sourcing Parts Separately
| Factor | Sourcing Separately | Compoden Kit |
|---|---|---|
| Compatibility checks | You verify every part | Pre-tested as a system |
| Build support | Forums and scattered tutorials | AI companion trained on this exact project |
| Time to first working build | Days of debugging | Hours, with step-by-step guidance |
| Shipping coordination | Multiple sellers, multiple delays | One shipment from Bengaluru in 3-5 days |
Who This Kit Is For
B.Tech ECE/EEE students building renewable energy projects, Smart India Hackathon participants tackling solar monitoring challenges, and engineering final‑year students needing a robust IoT data‑logger will find this kit directly applicable. It’s also perfect for hobbyists who want hard numbers on whether rooftop solar makes financial sense for their home, and ATL Tinkering Lab mentors demonstrating real‑world energy metering.
Built and Backed by Compoden
Every Compoden kit ships with an AI build companion trained on this exact project — accessible via a QR code on the box, with WhatsApp and email backup. We've spent 10 years building projects for makers, schools, and institutions across India. If a part fails because of a manufacturing defect, replace it free within 7 days.
What if I get stuck during the build?
The AI companion provides circuit diagrams, code walkthroughs, and debugging tips specific to this kit. You can also message us on WhatsApp for direct guidance from our team.
Can I use this kit with an actual rooftop solar panel?
Yes. The included 6V 2W panel is for bench testing. Once calibrated, connect the INA219 sensors to your real solar array’s DC output (up to 26V, 3.2A) to monitor actual generation and compute real‑world ROI.
Does the ESP8266 support cloud logging?
The ESP8266 hosts a local web dashboard. For cloud storage, our AI companion includes optional templates to push data to platforms like ThingSpeak — no continuous internet connection needed on the device side.
What soldering experience is required?
You’ll solder through‑hole components onto the prototype PCBs. The included soldering iron and the AI companion’s video instructions make it manageable even if your soldering skills are basic, but familiarity is recommended for this advanced kit.
INA219 logs real daily kWh. DS3231 tracks months of data. ESP8266 calculates payback period vs install cost.
What's in this kit
Choose your assembly option:
- Soldering Kit — 25W soldering iron, 60/40 solder wire, flux, and small perfboard for permanent assembly.
- Breadboard Combo — 800-point full-size breadboard with 65-piece jumper wire pack for solderless prototyping.
Other projects you can build
Shipping Information
- Prepaid Orders: ₹75 for orders up to ₹999, FREE shipping above ₹999
- COD Orders: ₹125 shipping + ₹50 COD fee = ₹175 total
- Delivery Timeline: Dispatch in 1-2 days, delivery in 2-7 days depending on location
Returns & Warranty
- 7-Day Return: Manufacturing defects only (approval required)
- Warranty: 7 days from delivery
- Non-Returnable: Batteries, consumables, cut wires, clearance items