AC or DC Coupled?
What is AC Coupled?
AC Coupled is a way in which a Home Storage Battery is connected. It is connected to your Home via it's own independent Circuit. The Battery which can only storage DC power will have it's own Inverter, usually built into the Battery unit. Making this a stand alone bit of equipment.
​
AC coupled Batteries have become very popular as you do not need Solar PV with these, they can be charged via an off peak tariff and them used or discharged during the peak duration to save you money on your bills.
​
AC Coupled Batteries can also be an addition to an existing Solar PV installation, so there is no need to change or replace your existing Inverter. Having 2 Inverters also means that if one fails then it will not affect the other.
​
What is DC Coupled?
DC Coupled Batteries is also a Home Storage Battery, this is connected differently to the AC Coupled Batteries.
​
DC Coupled Batteries make up part of your Solar PV system. They require a Hybrid Inverter, this one Inverter will be connected to your Solar Panels and also the Battery. It will make decisions to either store the power generated by your Solar Panels or send it straight to your Home for immediate use.
​
Having one Inverter has the potential to disable both your Solar PV and your Battery with one point of failure.
Advantages & Disadvantages of AC Coupled
ADVANTAGES
-
Retrofitting - AC Coupled Batteries are ideal for an existing Solar PV system of even on their own.
-
Reliability - Having an AC Coupled Battery a single fault will not affect your Solar PV and vice versa.
-
Flexibility - Whilst Solar Inverters like cooler temperatures, Batteries like around 20°C meaning you could position this somewhere else
DISADVANTAGES
-
Additional Cost - AC Coupled Battery will require an additional Inverter which is usually built into the Battery.
-
Losses - Due to the extra AC to DC conversions there will be small losses.
Advantages & Disadvantages of DC Coupled
ADVANTAGES
-
Cost - Due to the Solar PV & the Battery having the same Inverter, the cost is likely to be less of an AC Coupled Battery.
-
Losses - As there is only one Inverter there will be less losses due to conversions.
DISADVANTAGES
-
Installation - Due to the Inverter being connected to both the Solar PV and the Battery, you have less options for location due to cable lengths.
