DC Coupled Systems
DC Coupled Systems – Off Grid and Grid Tied
Historically, DC coupled Solar Battery Systems were only used in remote locations and off grid properties. Advancing technology, especially in relation to inverters, has seen significant progress for both DC and AC coupled Energy Storage.
DC coupled Hybrid systems are frequently referred to as a grid-tied DC Coupled Solar Battery System. These complete systems usually comprise of a Multi Mode Inverter or Hybrid inverter, which is used to manage both the solar system and the battery within a single unit.
DC Coupled Systems using a Hybrid Solar Inverter are still the most efficient and are likely to be for some time, due to higher voltage DC Battery Systems becoming increasingly popular alongside hybrid inverters.
Larger systems (greater than 2-3KW) normally use MPPT solar charge controllers. These ‘Maximum Power Point Trackers’ convert higher voltage DC output from solar panels to the lower voltage needed to charge batteries. In the event of an AC shutdown or grid power outage, the MPPT charge controller is an inexpensive and efficient way to ensure your batteries are charged.
Pro’s
- Up to 99% Battery Charging Efficiency when using MPPT
- Low cost, perfect for smaller off grid systems under 6kW
- A great solution for smaller 1-2KW Solar Panel setups for automobiles, marine and small off-grid applications
- Expandable – Easy addition of panels and controllers if required
- Highly effective for powering DC appliances and loads
- Flexible – Where grid tied Solar capacity is restricted, additional solar can be added by DC coupling a battery system and MPPT controllers.
Cons’s
- Can be complex to set up for larger systems above 6kW
- Efficiency may drop slightly when powering large AC loads throughout the day due to conversion between DC (PV) and DC (Battery) to AC.
- Costs may rise for systems above 6kW as multiple higher voltage solar charge controllers are required.
- Some solar controllers are not compatible with managed lithium battery systems.
Read our article which covers all the main Solar Battery Systems types here.
Soltaro offer both AC or DC Coupled systems to suit your needs – Find out more by visiting our products page.
The Soltaro AIO2
The Soltaro AIO2 stands apart as a hybrid system.
Our R&D teams have combined the best of AC and DC Coupled to achieve the best and most efficient solar battery storage.
By utilizing a PV-Battery DC charger, the AIO2 achieves extremely high efficiencies for Battery Charging from Solar PV. This is similar to the DC Coupled scenario we described earlier on this page.
Read More about the AIO2 here