DC vs AC coupling

Typical AC coupled Solar

• If using a typical GRID tied solar inverter system

• If solar only source of energy then approximately ⅔ or more of energy must be stored in battery first before going to customer

• This means additional losses as energy must flow through TWO additional inverter conversions

• Need a Full power rated change over switch if grid goes down

• There is power interruption and possible spikes etc during the change over time

• The solar grid tied inverter must typically be 5 times larger than the average load

• Difficult and complex to keep system stable without external grid

• Battery inverters must be more powerful than solar inverters and keep internal grid stable

• I.e. battery inverters also have to be more than 5 times larger than average load

• Above demonstrated in following graphic

DC coupled advantages