Bringing solar power solutions to individuals in the North Quabbin region

 

Give Stefan a call:

978-516-8303

 

 

In order to benefit from your existing solar photo voltaic system during a grid outage, additional equipment including a battery bank needs to be installed.

AC and DC coupling

People with existing grid-tie only systems, which is by far the most common solar photo-voltaic system, are often surprised by the fact that they have no power during a grid outage even if the sun is going strong. Grid-tied only inverters can not and are not allowed to function without the power grid. In order to benefit from your existing solar photo voltaic system during a grid outage, additional equipment including a battery bank needs to be installed. AC coupling and DC coupling are two common solutions.

DC coupling

With DC coupling a battery bank gets charged from the PV panels. During a power outage a second smaller inverter powers critical appliances like a water pump or furnace around the clock. DC coupled systems can be sized smaller for only 1 or 2 critical appliances and therefore tend to be less expensive. This solution is compatible with most 2+ year old grid tied inverters.

AC coupling

With AC coupling a battery bank gets charged from the power grid. During a power outage a second smaller inverter will fool the grid-tied inverter into ‘thinking’ the grid is present so that it can power your house and charge the batteries. During the no-sun hours the smaller inverter will power critical appliances like well pumps, furnaces and freezers. Depending on battery bank size this solution can cost $5,000 - $10,000. This solution should be compatible with most grid-tied inverters including micro inverters.

Stefan Maier, Design and Engineering

Domestic DC Systems

Orange, Massachusetts, USA

978-516-8303