Sizing solar for a tiny home with multiple occupants — how to adjust?

Understanding Occupant Load and Energy Demand

When sizing solar for a tiny home with multiple occupants, it’s essential to consider their energy usage patterns and lifestyle. A single occupant typically requires around 200-400 kWh per month, while a household of two to three occupants can consume 400-800 kWh per month. For each additional occupant, increase the system capacity by 10-20% to account for their energy demands. For example, a household of four occupants might require a 1.2-1.6 kW solar system.

Calculating System Capacity and Battery Storage

To determine the required system capacity, consider the household’s daily energy needs. A typical tiny home requires around 5-10 kWh of energy per day. Multiply this number by the household’s average daily usage, and then by the number of days the system needs to operate without sunlight (usually 3-5 days). For a household of four occupants, a 3 kW solar system with a 5 kWh battery bank could provide approximately 4-6 days of autonomy during periods of low sunlight.

Consideration of System Losses and Efficiency

System losses, including panel efficiency, inverter efficiency, and wiring losses, can reduce the overall system capacity by 10-20%. To account for these losses, increase the system capacity by 10-20% to ensure the household’s energy demands are met. For example, a 3 kW solar system with 10% losses would require a 3.3 kW system to produce the same amount of energy.