How are solar PV and battery storage systems integrated?

Integration approaches: DC-coupled (batteries connect to DC side via charge controller, shares inverter, simpler, allows solar charging without grid), AC-coupled (separate battery inverter, grid connection independent, easier retrofit, flexible sizing), and hybrid inverters (integrated solar and battery inverter in one unit, residential). Control strategies: self-consumption maximization (store excess solar for evening), peak shaving (reduce demand charges), time-of-use arbitrage, grid services (frequency regulation, capacity), and backup power. System design must consider: inverter sizing, battery autonomy, cycling requirements, and warranty implications.