Adding a battery to solar you already have

Plenty of Newcastle homes put solar on years ago, watched their feed-in tariff shrink, and are now looking at storage. Good news: most of those systems can take a battery. Here's how we work out whether yours should.

What we check first

• The age and condition of your existing inverter, and whether it's still under warranty.
• Your switchboard — capacity, condition and whether it meets current requirements.
• The array itself: output per string, panel condition, isolator condition.
• Your consumption pattern, so the battery is sized to your evenings rather than your roof.

AC coupled or DC coupled

A DC-coupled retrofit ties the battery into the solar side, usually by replacing your existing inverter with a hybrid one. An AC-coupled retrofit adds a separate battery inverter and leaves your solar as it is. AC coupling keeps a healthy existing inverter in service; DC coupling is usually more efficient and tidier if the inverter is due for replacement anyway.

When a retrofit doesn't stack up

If your inverter is near end of life, your array is small, or the system was poorly installed to start with, spending money bolting storage onto it is throwing good money after bad. Sometimes replacing the system and adding a battery in one go costs less over ten years than two separate jobs.

We'll say so when that's the case. We'd rather lose a small job than install storage onto a system that's about to give you grief.

Don't forget the switchboard

This is the one that catches people out. Older Newcastle boards frequently need work before a battery can be connected safely. We assess it during the site visit and include any upgrade in the quote up front, rather than raising it as a variation halfway through install day.