Step 1: Identify Your Appliances

List all electrical appliances you use daily (lights, fridge, TV, air conditioner, etc.). Note their power rating in watts (W).

Step 2: Calculate Daily Consumption

Multiply the power rating (W) of each appliance by the number of hours used per day. Example:

• Fridge: 150W × 24h = 3600 Wh
• TV: 100W × 4h = 400 Wh
• Lights: 60W × 5h × 5 bulbs = 1500 Wh

Total daily consumption = 5500 Wh (5.5 kWh).

Step 3: Adjust for System Losses

Solar systems lose about 20% due to inefficiencies. Multiply your total by 1.2. Example: 5.5 kWh × 1.2 = 6.6 kWh.

Step 4: Determine Solar Panel Size

If one panel produces 300W and generates about 1.5 kWh/day, you’ll need around 5 panels to cover 6.6 kWh/day.

Step 5: Consider Battery Storage

To store energy for night use, calculate battery capacity. Example: 6.6 kWh ÷ 12V = 550 Ah. You may need multiple batteries depending on voltage and capacity.

Frequently Asked Questions (FAQ)

How many solar panels do I need for a small house?

Typically, 5–10 panels depending on daily consumption and panel wattage.

Do I need batteries for my solar system?

Batteries are optional but recommended if you want backup power at night or during outages.

Can I expand my solar system later?

Yes, most systems are scalable. You can add more panels or batteries as your energy needs grow.