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​Upgrading your solar energy system to work with battery storage

As solar feed-in tariffs drop far below the rates paid for grid electricity, a growing number of homeowners are looking for ways to cut bills by making better use of their excess solar power generation.

With no one home during the day to use your solar power, you might end up selling your excess solar energy to your electricity retailer at something between 10 to 20% of the price which they then sell back to you at night.

If you’re generating more power than you consume during daylight hours, adding a battery storage solution to your existing solar system can be one of the best ways to reduce your power bills. Imagine being able to not only generate your own electricity, but also having the ability to store your power during the day, and use it when you get home at night, or in some cases even during a power outage.

Battery storage systems are an increasingly affordable solution for homeowners who want to reduce their reliance on grid power, or remove themselves from the grid entirely. If you’re considering adding batteries to your existing solar system and want to know more about the process, we’ve got you covered.

Read on for answers to the most common questions we get about upgrading an existing solar system with battery storage.

Does my solar system work with a battery?

Every solar energy system sold by ZEN today, and almost any other system, can be connected to battery storage. This means that even if you aren’t quite ready for storage just yet, simply buying solar today is still a risk free investment for the future of your home.

Selecting the right battery storage solution to work with your existing solar panels depends on a number of factors, including what feed-in tariff you’re currently on, and what you want to achieve with battery storage.

Your battery storage provider should know the ins and outs of your existing solar energy system before making a recommendation, otherwise they might sell you a system that works best for their bottom line, instead of a system that is built to last and suits your unique situation. Some of the essential questions your solar provider should ask about your existing solar energy system include:

If you’re on one of the generous early solar feed-in tariffs and your motivations are purely financial, you may be better off not installing battery storage because you will lose your existing tariff and move to today’s much lower tariff rates. But of course if you are not exporting enough energy to actually benefit from the tariff and/or your motivations are more around electricity security or blackout power, battery storage may still be an option for you.

The answer to this will help your provider determine whether you have enough existing solar to feed a battery storage system or if you need more solar as well, and also what battery size you should choose. Be aware that some battery storage systems are modular, so you can start with a small storage system if you prefer and then upgrade over time.

Some battery storage systems are available in just single-phase, while some are available in both single-phase and three-phase. Whilst a single phase unit can often be connected to a three-phase home and/or three-phase solar energy system, you may want to consider a full three-phase storage system if your goal is to fully maximise the benefits of shifting solar energy from daytime to night-time.

The answer to this question will help get the necessary approvals for your battery storage system as quickly as possible and, depending on your electricity distributor and the rules they place around battery storage installations in their area, might even guide the type and size of battery storage system you can install.

What is most important in selecting your battery storage system? Is it about having power during a blackout? Or is it about maximising the financial and/or environmental benefits of using your own solar energy instead of grid power? Some battery storage systems are better than others when it comes to these sort of factors, so it’s important to know what is a “nice to have” and a “need to have” when selecting the best battery storage system for your situation.

Can I upgrade my solar?

Yes, you can absolutely upgrade your solar, and in many cases that’s exactly what people do when they add battery storage to an existing solar energy system. You might consider upgrading or adding to your existing solar to make sure you are “load-shifting” or generating enough power to not only cover your daytime needs, but also your night-time needs too.

It’s important to know that upgrading or adding to your existing solar doesn’t necessarily mean your provider will physically touch or rewire your existing solar energy system. If they do, they are often obligated under various regulations to bring all of your existing system up to the most current electricity wiring standards (even if it working properly) which can potentially add thousands of unnecessary dollars to a system installation.

At ZEN Energy, in nearly all cases, we leave your existing panels and inverter in place and simply install additional panels and a new inverter as a new system “side by side” with your existing system so that the two can work together to feed into a battery and reduce your reliance on grid electricity.

Solar panels on a residential roof

How long does a solar and battery storage system take to ‘payback’?

A well designed battery storage system that is combined with new solar panels will typically take between 6 and 12 years to payback. If anyone tells you their system will pay itself back significantly quicker than this, be warned – when something seems too good to be true, it often is!

Keep in mind that if you don’t add new solar panels with your battery storage system, the payback period will be longer. However, just like any major investment, you should consider the full range of benefits that battery storage can offer (not just the payback period) including:

  • Use more of your own solar energy.
  • Reduce your grid costs and reliance on grid electricity.
  • Have backup power in a blackout.
  • Reduce your carbon footprint with cleaner, greener energy use.
  • Reduce the impact of future electricity price increases.
  • Take your home entirely off grid (if you wish!)

How long do solar panels (without a battery) take to ‘payback’?

A solar energy system without a battery will typically take between 3 and 5 years to payback if it is well-suited to your daytime energy needs.

However if you’re looking to install solar panels now, but would like to upgrade to battery storage in the future, you need a system that is sized with your typical 24-hour energy needs (not just your daytime needs).

Before you add a battery, this just means that your solar energy system will send a reasonable amount of energy back to the grid. However, because you will have done the solar panel work up front, you won’t need to add more panels to your roof when you’re ready to add battery storage – your system will already be well-sized to cover both your daytime needs and feed energy into a battery for night-time use.

Will I be “off the grid”?

Yes, you can certainly take your whole home off grid if that’s what you want!

However in many cases, we find that most people opt for “grid-connect” battery storage systems that can provide the benefits of being 70 – 95% grid independent, but still have the grid there as a backup to dip into at your convenience. Where a grid connection is available to a property, the supply charge cost of having the grid as a backup often works out to a small price to pay for that extra bit of electricity security.

If you do want to get off the grid, keep in mind that your solar and battery storage system needs to be bigger and beefier than a grid-connect system to make sure you have power at all times, including during periods of bad weather, or at times of high energy use. This will obviously impact your budget and price, which a ZEN Energy Consultant is well placed to guide you through.

Are there minimum requirements for battery storage?

There are no minimum requirements for upgrading your existing solar system with battery storage. Some electricity distributors may place maximum restrictions on how big your solar and battery storage system can be depending on their local rules, but ZEN Energy Consultants can help you through that too.

Interested in finding out how battery storage can work for you?

Compare Storage Solutions

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