Energy storage has become very popular as power prices continue to escalate, some feed-in tariffs schemes end and as battery technology evolves. Prices of battery systems have also reduced drastically meaning more and more solar owners can store their generated energy for use at night.

Not everyone has an understanding of the reasons for all the hype about batteries. The following Solar Battery Guide will help pick apart the key motivations and possibilities for installing a battery system in your home.

Solar Battery Guide

Are solar batteries financially ‘viable’?

The answer is YES. It is very possible to achieve payback within the warranty period of 10 years. Consider this, what else have you ever bought that will pay for itself before the warranty expires (and then for many years more!)

What reasons are there for installing a battery?

Several times a day, our consultants at Envirogroup field calls from people wanting to know about batteries and if they should have one. Here are the key motivators for people to make that call:

  1. Independence from the energy companies either financially or physically.
  2. Blackout protection
  3. Environmental reasons.
  4. Early adopters and technophiles.

Independence financially from the energy companies is achievable but it might take up to 10 years to sail clean away since the payback periods for batteries is around 7-9 years. Removing yourself from the network is possible but extremely expensive and impractical for most. See below for more.

Blackout protection is certainly possible and is becoming a standard feature of new battery modules. Our Redback and Tesla systems do this very well. There are certain limitations, however, in what you can back up. At the moment, these systems are single phase only so there is a degree of switchboard work to be done to set up circuits that will be backed up. Generally, in the event of a power outage, you would want to back up your fridge, lighting and a power circuit to run things like a TV, computer, phone chargers and other important devices. It will not run an air-conditioner or an electric oven.

There is however, a good reason to install a battery that few people are aware of and that is the move from a centralized grid to a distributed grid. As more and more energy sources are being created and as old coal power stations are decommissioned, the way electricity is distributed has changed. We are moving away from the old model of having central power stations to having thousands of different generators all connected to each other. These could be large power stations, wind and solar farms, household solar or any other type of grid-connected generator.

This creates opportunities for the grid managers to control the stability of the grid and the residual capacity of your battery module will be connected up to hundreds of other batteries connected to the grid via a system called Virtual Power Plant or VPP. This cumulative surplus capacity will allow the grid managers to help stabilize the grid during network voltage events and you will accrue a tariff for participating in this service. So not only will your battery directly save you money by storing your excess solar, but it will accumulate credit when it’s used in a VPP. This system is currently underway in South Australia and parts of Western Australia and will eventually be adopted in Victoria. Your decision to have a battery means you can participate in the new energy market.

Is my solar system compatible with a solar battery?

The answer is YES. Despite a common solar marketplace misconception, the fact is ALL solar batteries can be compatible with any solar system. That’s because both your solar system and battery system are commonly plugged into your switchboard as two separate appliances, i.e. they don’t actually need to be plugged into each other to do their jobs.

Still not convinced? Give us a call and and we can review your existing system and tell you.

How many batteries do I need?

Every solar battery is different and they come in different sizes. The question is more accurately phrased: “How much energy storage do I need and what battery will meet my needs?”. We specialize in helping you answer these questions. Enquire today and we can use your electricity bills to tell you.

Can I go off-grid?

Sure, you can. We can do this for you right now if you have the money. But you will need a lot of money. And a generator. And constant energy management processes. And you don’t care about return on investment.

You see, once you go off-grid you are on your own. There’s no grid to help you out so if its 43 degrees in your bedroom in January and you run your 12kW ducted air-conditioner overnight…well, there is no overnight because your batteries will be flat and all your lights are out and your fridge is warming up. If you have a generator then it will get you out of trouble but start counting your diesel costs because that is going to hurt.

There are some people in remote locations who are far from the grid that absolutely need off-grid power and these people learn to manage their energy usage and have a backup generator. For those of us in the suburbs, being off-grid is a risky idea. A small off-grid system will cost around $20-40k and one that can run a family home will be around $50-100k. This is an investment of necessity not finance. The ROI is terrible .

OK, I’ll stay on the grid but what if I lose power?

This is a different scenario. You are not looking to run forever off-grid, just to keep the lights on and the fridge working in the event of an outage. This is achievable with the latest battery offerings but beware! It’s not as straightforward as slapping a battery box on your existing solar system and waiting to impress the neighbours in the next storm.

The battery modules we are selling these days are to help off-set your electricity bill. They are to take the residual solar power you generate, store it and then give it back to you when the sun has gone down. Some like the Tesla Powerwall 2, the Redback and the Enphase IQ8 system (coming soon) will keep certain circuits running when the grid is down.

These circuits, called maintenance or sustained circuits, will run some lights and a light power circuit that can run a computer or television and a fridge. It absolutely will not run your air-conditioner, your Smeg double oven or your welder. Now, you can connect several Teslas together to give you considerable backup where you might be able to run most of your gear within reason but the cost of this is nearly equal to an off-grid system.

You installed a 2kW system years ago, can I add a battery?

You can add a battery. However, a 2kW system is busy trying to run your house and there’s probably not a lot of surplus power to charge the battery each day. You will probably have to add substantially to your solar system in order to keep the battery charged and the house supplied, so systems below 5kW will probably struggle to do this. If you replace your inverter with a hybrid inverter then you can add panels to charge the battery. At any rate, you are going to have to call us to work this out.

What is ac and dc coupling?

This refers to the method of connection of battery systems to solar PV systems. With a dc system, everything takes place on the dc side of the system. You need battery inverter and a battery management system to do this. With a hybrid inverter the solar panels connect straight into the inverter as does the battery because a hybrid inverter contains the Battery Management System (BMS). If you don’t have a hybrid you will need to add a battery inverter and a BMS. It’s a very busy installation doing it this way. Our Redback system is a neat example of a dc coupled system

With an ac system, the battery system connects to the ac side of the solar. Brands like Tesla and Enphase are ac coupled. These modules connect up to the existing system without change but the battery module also contains the BMS and battery inverter.

Each method has its own advantages and disadvantages but each essentially delivers the same result. An ac coupled system is a simple retrofit to an existing solar system. The best system for you will be sorted out with a consultation and an energy assessment.

Can batteries be installed outside?

YES – at least all of the batteries in our range can. They can also be either wall or ground mounted. Be careful of cheaper brands that aren’t weather proofed…

How much will a battery cost me?

That depends on what you need. Most battery systems are in the range of $10,000 – $14,000 fully installed. Although, there are some small ones that are under $10,000, or cheap knock-offs from China that are even cheaper. Our experience is that “you get what you pay for”.

Are batteries dangerous?

Billions of dollars of R&D have gone into making the leading brands safe for consumers. Be careful of:

  • Cheaper knock-off batteries that get too hot or aren’t weather proofed
  • Someone installing one who isn’t CEC accredited, experienced or reputable!

Since 2008 we have installed both grid connected and off-grid battery systems, here are the current battery products we stock:

Our Residential Battery Solutions

tesla battery logo1

One of the most well-known brands of home battery currently available, Tesla Powerwall 2 has taken the whole world by storm. The first Powerwall was one of the most anticipated products ever released.

Owner and founder of Tesla, Elon Musk, also installed the world’s largest battery system for South Australia in late 2017, which uses the same technology as the Powerwall 2. The results have been staggering.

Tesla Powerwall 2, has a seriously large battery pack of 13.5 kWh which is enough for most homes (sometimes too much). Powerwall 2 also has a built-in battery inverter which means you don’t need to buy that extra bit of hardware. It is compatible with ANY solar power system.

We have installed many Powerwalls – EnviroGroup is proud to be one of the few Authorised Tesla Installers in Australia. Many of our customers have already signed up for one  and they very popular, so don’t wait longer than you should to get your own.

powerwall envirogroup
enphase battery logos2

Enphase Energy who are world leaders in Microinverter technology also offer their own AC Battery system. Starting in 1.2kWh units, the batteries are suitable for homes with smaller energy demands.

The compact battery system is designed to be modular so it can be easily expanded, so the system size can be tailored to your home’s needs no and in the future. Providing 100% depth of discharge, you can always be sure of the amount of power being stored for use.

The lithium iron phosphate (LiFePo4) battery comes with a built in battery inverter and uses the Enphase Envoy S for energy management and monitoring. The Envoy S which measures the home’s energy usage and solar generation, directs excess solar energy into the battery for use at night.

The Enphase AC Battery pairs perfectly with new and existing solar systems using microinverters.

enphase ac battery
redback logo

One of the most complete packages on the Australian battery market today. Redback is a Brisbane based company and have delivered on a product that not only provides grid-connected storage, blackout protection and modularity but is also price-disruptive. This means the Redback solution has a return on investment far more acceptable than its competitors.

The modular battery cabinet can take up to four Pylontech Lithium Iron Phosphate batteries or you can start with just the inverter cabinet on a standard PV system without the battery cabinet and ensure you are truly battery ready, adding the batteries later as you need them. Redback’s cloud based monitoring system also ensure that you have complete control and visibility over what your system is doing making your future energy smart home really smart.

We currently have a Redback system working in our showroom in Northcote. Come in and take a look.

redback on house

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