How Do Solar Battery Systems Work?

Battery storage system Components

According to Ausgrid, battery systems have three main components: The battery, inverter-charger and meter.

The battery is for energy storage, which is contained of individual battery cells wired together. They are capable of discharging and charging DC voltage and can be lead acid or Lithium-Ion batteries.

Most units include an inverter-charger for converting the DC electricity to AC for use in the house, they can also convert the power back to DC if you’re charging it from the mains power.

Additionally, there’s a balance of various system components from wiring and battery management systems to measurement and control components including meters and switches.

If you’re looking at a system that can run ‘off-grid’, you’ll need extra components such as change-over switches. Every battery manufacturer or supplier will offer a range of different products, many of which might have different levels of system integration and required installation work.

Different types of battery storage systems

Some manufacturers produce battery only systems, so you will need to have a battery installer integrate the system with a compatible inverter, control system, and solar panels.

In other cases, you may find a manufacturer who provides battery storage systems with inverters which can be installed on its own separately to your solar system. The most common option is an integrated solar and battery storage system which is made up of a single unit containing the inverter-charger and battery with the DC side of the solar power system connecting to the all-in-one.

1. The solar panels take in sunlight.
2. The solar energy travels as direct current (DC) through the solar inverter so it can be converted into alternating current (AC) energy that everyday appliances can use.
3. The switchboard then directs the solar energy to where it’s needed. First, it will power the appliances in your home, then direct any excess to the battery inverter.
4. The battery inverter converts the energy into a form of storable energy.
5. The battery stores the energy to use for when the sun goes down.

Now that the batteries are charged, once the solar panels stop generating energy the battery will send energy through the inverter to power the home. Once the energy has been converted to a useable form, the switchboard then directs the energy to whatever appliances are operating within your home.

If you are connected to the grid, once the battery’s charge is done your home will switch over. If you want to have a completely ’off-grid’ solar system, then you’ll need larger batteries such as deep cycle sealed gel batteries, or lithium-ion. 

‘Off-grid’ solar storage systems

If you’re looking to remove your home from the grid, travel without needing to plug in, or live somewhere remote without grid access you’ll want to have an off-grid solar system with enough solar panels to generate the amount of electricity you need (this can be discussed with your solar panel company), a charge controller, battery bank, solar inverter, and a generator in case of system failure.

These off-grid power systems can be small enough to run camper appliances, to large enough to run everything within your house or even bigger, check out some of JPAC’s projects to see how big you can go.

Your battery bank is used to store the excess solar power generated by the system which isn’t used by your appliances during daylight hours. Your system should have the capability to throttle back the solar power to prevent the batteries from getting damaged through overcharging.

Small usage

A small energy user could have a 3kW Solar System with a 10kWh battery which would cover approximately 95% of your annual energy requirements assuming an average of 10kWh of energy use each day. If you were to go up to a 5kW system you’d bump that up to 99%.

Medium usage

 If your household uses 15kWh per day, you’ll want to look at a 6kW Solar System with a 20KwH battery

Larger usage

If you’re using up to 20kWh per day, you’ll want to upgrade to an 8kW system. For larger homes which use around 35kWh per day, you’ll want to invest in a 10kW Solar System with a 30kWh battery to keep your home off-grid. If you want more than 92% energy usage coverage, consider upgrading to a 15kW system.

Industrial battery systems

With more strain being put on the grid throughout the year, especially during extremely hot summer days, if you’re a business owner you’ll want to have a buffer against power outages.

While generators were the go-to of the past, today we are seeing more and more companies from telecommunication to railways and even the Australian Mining Industry are all investing in industrial battery systems. While you might think these industries would be safe from blackouts, they do sometimes suffer catastrophic failure or are based in areas where grid connection is impossible.

Since batteries are a safe and long-lasting solution in power storage, having a solar system set up with batteries which can be charged during the day you can rest assured knowing that your systems will continue operating throughout the night.