The 5 Main Parts Of An Off-Grid System
- Battery Inverter/charger or Multi-mode hy brid inverter
- Solar inverter (AC) or MPPT Solar charge controllers (DC)
- Battery bank
- Solar panels
- Generator (Optional)
Off-grid system types - AC or DC-coupled
Off-grid systems are built using either AC or DC-coupled power sources. AC-coupled generation sources include common solar inverters, wind turbines or backup generators (gen-sets), while DC-coupled sources include MPPT solar charge controllers or micro-hydro systems.
Whether a system is AC or DC-coupled is generally based on the size of the system. Most small-scale systems are DC-coupled and use efficient MPPT solar charge controllers. Larger off-grid systems can be either AC or DC-coupled depending on the type of off-grid inverter-charger used, and compatibility with different solar inverters (AC) or solar charge controllers (DC). Most modern inverter-chargers can be both AC and DC-coupled, which creates a very secure, flexible power system with multiple charging options and can enable black-start operation if the main inverter shuts down, the backup generator fails or the batteries are depleted.
DC-coupled solar charge controllers have been around for decades and are available in two main types, PWM and MPPT. Learn more about solar charge controllers here, plus how to size small-scale off-grid solar systems correctly. More powerful MPPT Solar charge controllers up to 100A are used on larger scale off-grid solar power systems. These are a very efficient and reliable way of charging and managing high-capacity lithium or lead-acid battery systems.