A DC-coupling may be referred to as when a single converter powers the batteries and solar panels simultaneously. A DC charger is used to power the batteries with DC from the solar panels.
Simply put, AC or DC coupling refers to the connection or coupling of solar panels to a battery device. A solar setup and a battery can be connected electrically using either direct current (DC) or alternating current (AC) (DC). DC is where the current flows in only one way, while AC is when the current flows quickly both forward and backward (this is how the electricity grid works). The majority of electrical circuits work with DC, which is also produced by solar panels and stored in batteries. The majority of electrical tools, though, use AC. Due to this, AC circuits are present in every home and company. An inverter can convert DC to AC, but as will be shown below, there is always some energy wasted in the process.
How Does DC Coupling Work?
A charge controller in a DC-coupled system allows DC electricity from the solar panels to be sent directly to the system’s batteries, bypassing the need for an inverter. An inverter is still used to convert DC power to AC for use in appliances or to supply the main grid, but this is the only inverter required. Because of this, DC-coupled systems are easier to understand and, in general, more effective than AC-coupled ones.
Must Read: What is AC Coupling?
Where is DC Coupling Used?
The best choice for smaller-scale domestic off-grid systems and small mobile systems used in RVs and caravans is DC-coupling using MPPT solar charge controllers. For grid-tied energy storage systems and bigger off-grid systems, AC-coupling using solar inverters is significantly more effective, particularly when the daytime loads are high. Below is a detailed explanation of each system type’s complete set of benefits and drawbacks.
DC-coupled systems have been used for years in small-capacity automotive/boating power systems and off-grid solar setups. Solar charge controllers, also referred to as solar regulators, are used in the majority of DC-coupled systems to charge a battery straight from the sun. In most cases, these systems use a battery inverter-charger to provide AC electricity to home appliances.