How should I size a patio system to cover lighting and outlets?

Sizing a patio PV system for lighting and outlets

Sizing depends on expected loads and local sunlight. Start by listing devices and their daily energy use, then calculate required panel capacity.

Sizing steps:

• Inventory loads: list wattage and hours per day for lights, chargers, speakers, and any appliances
• Sum daily energy (Wh): e.g., 10 LED bulbs × 8 W × 4 hours = 320 Wh
• Divide by average peak sun hours for your location (commonly 3–5) to find required wattage
• Add a margin (15–25%) for system losses

Example: If your patio loads total 1 kWh/day and you get 4 peak sun hours, you need about 250 W of panels (1,000 Wh / 4 h = 250 W). Adding 20% losses suggests sizing to ~300 W.

Also consider inverter efficiency, if you want backup during evening hours (add battery storage), and whether you plan to expand loads later. A modestly oversized system gives flexibility while keeping costs reasonable. Consult a site-specific assessment for exact sizing.