Adding a battery to your existing solar power system is not always an easy task. If your solar power system was installed storage-ready, adding the battery could be easy but with the rapid advancements of solar-plus-storage in the last few years, it is unlikely many old solar systems can easily accommodate battery connection. But that does not mean it is impossible; there are just a few important questions you must answer before starting a retrofit solar-plus-storage installation project.

What is your inverters make and model?

The inverter used on an existing solar panel system will dictate how a battery can be added to an existing solar power system. Solar-plus-storage systems are either AC-coupled or DC-coupled. AC-coupled systems require an additional, separate inverter to charge the batteries. DC-coupled systems use a charge controller to feed the power from the solar array to the batteries and then through an inverter for grid-tied use. For example, existing systems with microinverters which make the DC-AC conversion at the panel-level will need an AC-coupled system for storage, since the battery cannot be incorporated into the DC lines before AC-conversion.

To accommodate energy storage in an AC coupled system, existing grid-tie inverters must have frequency control capability. If the existing older inverters cannot frequency shift, they should be replaced to add batteries. Adding new inverter that can regulate charges is the only way to include storage on this type of existing solar PV system. Inverters are usually warrantied to 5 /10 years. If the inverter is approaching its warrantied lifespan, it’s a good idea to upgrade. It may be advantageous to replace the inverter with an inverter designed to accommodate storage to enable options to integrate storage immediately or in the future.

Why do you want to add storage?

Another question to answer – is your storage solution for emergency power? Or to store excess energy produced by solar during the day, so that it can be used in the evening when the sun goes down? Or in places with a TOU tariff, charge the batteries with solar or grid power when rates are cheap and discharge the batteries when power is most expensive. Depending on your objective, it is important to have an inverter that allows for your specific storage need and an appropriately sized battery bank to support your power needs.

Who owns the solar system?

Another question to answer – is your existing solar PV system owned by you or leased?  If you have full ownership adding storage is easy. If your existing solar panel system leased it may have restrictions on adding certain equipment. Typically leased solar power systems have a wide range of restrictions as to what changes can be made to the home or business and its electrical loads. Adding energy storage may be prohibited by lease terms.

If you are thinking of adding energy storage to your existing solar PV system and much it would cost to have peace of mind with a solar plus battery power system complete the Free solar Assessment request at our website or give us a call at 416-855-9377.

We are one of the top solar energy companies providing solutions that are second to none. We provide solar plus storage hybrid energy solutions across Ontario including Toronto, Markham, Mississauga, Burlington, Oakville, Brampton, Vaughan, Ajax, Pickering, Whitby, Oshawa, Caledon, Stouffville, Richmond Hill, Newmarket, Aurora, Milton, Georgetown, and the Greater Toronto Area (GTA).