Ettronics Solar System Calculator Documentation
A complete user guide for installing, configuring, and using the Ettronics Solar System Calculator to estimate solar panels, batteries, inverter size, charge controller rating, ROI, generator size, and AI-powered recommendations.
Introduction
The Ettronics Solar System Calculator is a professional solar power system sizing tool designed to help homeowners, businesses, solar installers, students, engineers, and renewable energy enthusiasts estimate the major components required for a solar energy system.
Important Disclaimer
Before purchasing equipment or installing a solar power system, all calculations should be verified by a qualified solar installer, electrical engineer, or renewable energy professional.
Actual system performance depends on site conditions, solar irradiation, temperature, cable size, equipment quality, shading, local electrical codes, manufacturer specifications, protection devices, and installation workmanship.
Understanding Basic and Advanced Modes
| Mode | What It Does | Best For |
|---|---|---|
| Basic Mode | Calculates the core solar system sizing results such as solar array size, panel count, battery capacity, inverter size, charge controller rating, and daily production. | Beginners, homeowners, quick estimates, and simple backup power planning. |
| Advanced Mode | Unlocks additional modules such as Battery, ROI, and Compare. These options provide more detailed analysis and configuration comparison. | Solar installers, consultants, engineers, trainers, and commercial planning. |
Main Solar System Inputs
| Input Field | Meaning | Example | Why It Matters |
|---|---|---|---|
| Daily Load (W) | Total power consumed by all appliances at the same time. | 1000 W | Determines the size of the inverter and daily energy demand. |
| Hours of Use | Average number of hours the load operates per day. | 5 hours | Used to calculate daily energy consumption. |
| Battery System Voltage | The voltage of the full battery bank. | 12 V, 24 V, 48 V | Higher system voltage reduces current and cable stress. |
| Single Battery Voltage | The voltage rating of one battery. | 12 V | Used to calculate batteries in series and parallel. |
| Days of Autonomy | Number of days the battery should power the load without solar charging. | 1–3 days | Important for cloudy weather and off-grid reliability. |
| Inverter Efficiency | Efficiency of DC-to-AC conversion. | 90% or 95% | Accounts for energy loss when using AC appliances. |
| Peak Sun Hours | Equivalent hours of strong sunlight per day. | 5 hours | Used to estimate required solar panel capacity. |
| Solar Panel Wattage | Rated wattage of one solar panel. | 550 W | Used to calculate the number of panels required. |
Daily Energy Formula
For example, a 1000 W load used for 5 hours consumes 1000 × 5 = 5000 Wh per day.
Battery Module
The Battery module becomes available in Advanced Mode. It helps users select battery technology and estimate the required battery bank configuration.
| Battery Type | Typical Depth of Discharge | Advantages | Limitations |
|---|---|---|---|
| Lead Acid | 50% | Lower upfront cost and widely available. | Heavy, shorter lifespan, lower usable capacity. |
| AGM | 50% | Maintenance-free and better sealed construction. | More expensive than flooded lead acid. |
| Gel | 60% | Good deep-cycle performance. | Sensitive to charging parameters. |
| Lithium LiFePO4 | 80–90% | Long lifespan, lightweight, high usable capacity, better efficiency. | Higher initial purchase cost. |
Battery Configuration
The calculator estimates how many batteries are needed in series to achieve the battery bank voltage and how many parallel strings are needed to reach the required capacity.
ROI Module
The ROI module estimates financial performance using installation cost and electricity savings.
| Financial Term | Meaning | Formula / Use |
|---|---|---|
| Installation Cost | Total cost of the solar project. | Panels + batteries + inverter + controller + cables + labour. |
| Annual Savings | Estimated yearly electricity cost saved. | Annual energy offset × local energy price. |
| Payback Period | Time required to recover the investment. | Installation Cost ÷ Annual Savings. |
| ROI | Return on Investment. | (Annual Savings ÷ Installation Cost) × 100. |
Compare Module
The Compare module allows users to save and compare different solar configurations. This is useful when comparing different panel wattages, battery technologies, battery capacities, inverter sizes, or system voltages.
Understanding the Results
| Result | Meaning |
|---|---|
| Solar Array Size | Total solar panel wattage needed to meet the energy requirement. |
| Number of Panels | Total panel count based on the selected panel wattage. |
| Battery Bank Capacity | Required energy storage capacity in ampere-hours at the selected system voltage. |
| Battery Configuration | How many batteries are connected in series and parallel. |
| Inverter Size | Minimum recommended inverter output size with safety margin. |
| Charge Controller Size | Recommended MPPT charge controller current rating. |
| Estimated Daily Production | Approximate daily energy generation from the solar array. |
| Generator Recommendation | Suggested backup generator size for hybrid or backup systems. |
AI Recommendations
The calculator can optionally generate AI-powered recommendations based on the calculated result. The AI is intended to explain and interpret the results, not replace the formula-based calculator engine.
The AI May Provide
System Summary Battery Recommendation Inverter Recommendation Wire Sizing Guidance Safety Notes ROI Comment Suggested ImprovementsCopy and Print Report
The Copy and Print functions are designed to help users save or share their results. The report should include only the calculated results and recommendations, not the full page introduction or instructional content.
| Action | Expected Output |
|---|---|
| Copy Report | Copies calculated result values, professional recommendations, and AI recommendation if available. |
| Print Report | Opens a printable report containing system sizing results and recommendations only. |
Safety Recommendations
- Use correctly rated DC and AC cables.
- Install properly rated fuses and circuit breakers.
- Use appropriate earthing/grounding and surge protection.
- Confirm PV open-circuit voltage and short-circuit current before selecting an MPPT controller.
- Follow manufacturer datasheets and local wiring regulations.
- Consult a qualified installer before connecting any solar system to a building distribution board.
Frequently Asked Questions
Is the Ettronics Solar System Calculator accurate?
It is accurate for preliminary sizing based on the values entered by the user. It should not be treated as a certified final installation design.
Can I use it for commercial projects?
Yes, it can support preliminary commercial planning, but a qualified professional should verify final design decisions.
Which battery type is best?
Lithium LiFePO4 is often recommended for modern systems because it offers longer life, higher usable capacity, and better efficiency, although it costs more upfront.
Why does battery voltage matter?
Higher battery bank voltage reduces current, which can reduce cable losses and improve system efficiency for larger installations.
Can the AI design my solar installation?
No. The AI can explain results and provide suggestions, but it cannot replace certified engineering design or local code compliance.