Executive Summary Glossary 1 Introduction 1.1 Storing Solar Surplus 1.2 Providing a Back-up Power Supply 2 Batteries 2.1 Lead-acid Batteries 2.2 Lithium-ion Batteries 2.3 Battery Characteristics 3 Battery Charging 3.1 Charge Profile for Lead-acid Batteries 3.2 Charge Profile for Lithium-ion Batteries 3.3 Opportunity Charging 3.4 Charge Profile for Grid-connected PV Storage Systems 4 System Components and Configurations 4.1 System Components 4.2 System Configurations 5 System Operation 5.1 Introduction 5.2 Basic Time-shifting Operation 5.3 Average vs Peak Load Profile 5.4 Winter Mode 5.5 Other Operating Modes 6 Design and Installation Requirements 6.1 System Sizing 6.2 Component Intercompatibility 6.3 Battery Protection 6.4 PV Array/String Overcurrent Protection 6.5 DC Cables and Component Ratings 6.6 Inverter/Charger Location 6.7 Battery Installation 6.8 Isolation and Switching for Off-grid Operation 6.9 Hazard Warning Signs 7 References and Further Reading 7.1 References 7.2 Further Reading