How many solar panels for a large 300 m² (3200 sqft) home
A 3200 sqft home with pool, central AC, heat pump and EV can use 18000 kWh/year. You need 25-40 panels.
Large detached home with pool, central AC, American appliances and possibly EV. Consumption here easily reaches 12000-18000 kWh/year. A serious install is 7-10 kWp.
Consumption by category
Heat pump heating (6 months): 4000 kWh. Summer AC: 2500 kWh. Pool (filter + heat pump): 3500 kWh. Heat-pump water heater: 1500 kWh. Cooking, appliances, lighting: 3000 kWh. EV (10000 mi): 3000 kWh. Total: 17500 kWh/year.
Panel calculation
12000 kWh/year = 8.3 kWp = 20 panels. 17500 kWh/year = 12 kWp = 30 panels. Planning more loads later? Oversize 25% minimum.
Inverter mandatorily three-phase / split-phase
Large US homes have 200 A split-phase. Many EU large homes have three-phase service. Single-phase inverter dumps all surplus into one leg, not balancing. Three-phase or split-phase 10-15 kW hybrid is the pick.
Battery: when it pays
On this home, 10-20 kWh battery allows ~85% self-consumption. Investment $9000-17000. Payback with expensive grid: 7-10 years. If grid stable and 1:1 net metering, battery optional.
Full install cost
10 kWp with three-phase hybrid: $18000-25000. 15 kWh battery: +$11000. EV charger: +$1000. Total with battery and charger: $30000-37000. Tax credits cut 30-40%.
Compare with 2200 sqft home and EV charging.
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