Minimum solar panel output for basic off-grid appliances?

Sizing a Basic Off-Grid Solar System

When sizing a basic off-grid solar system, it’s essential to calculate the total load or energy requirements of the household appliances. A typical off-grid system can power appliances like lights (50W), a small refrigerator (100W), a laptop (50W), and other low-power devices. A good starting point is to calculate the daily load requirement in watt-hours (Wh). For a small household, a daily load of 1-2 kWh (1000-2000 Wh) is a reasonable estimate.

Calculating Daily Load Requirement

To calculate the daily load requirement, identify the appliances to be powered, their power ratings, and the usage hours per day. For example, a small LED light (5W) used for 8 hours, a laptop (50W) used for 4 hours, and a small refrigerator (100W) used for 8 hours. Add up the total watt-hours: 5W * 8h + 50W * 4h + 100W * 8h = 40Wh + 200Wh + 800Wh = 1040Wh or 1.04 kWh.

Sizing Solar Panels, Batteries, and Inverters

Based on the calculated daily load requirement, size the solar panels, batteries, and inverter accordingly. For a 1.04 kWh daily load, a 300-500 watt solar panel array can provide sufficient energy to charge the batteries. A deep cycle battery bank of 400-800 Ah capacity can store the excess energy generated by the solar panels. A 2000W inverter can convert the DC power from the solar panels and batteries to AC power for household appliances.

Worksheet Example

To illustrate the process, consider the following worksheet example:

| Solar Panel Array | | 300-500W | | Battery Bank | | 400-800Ah | | Inverter | | 2000W |