Home solar battery cost and sizing explained
Hybrid & off-grid solar systems cost guide
Hybrid battery system installed by Skyline Solar
This is a general guide for solar battery system sizing and costs based on the energy consumption of an 'efficient’ 3-bedroom home with an average energy use of 15kWh per day. Remember, every household is unique, and there are many ways to reduce energy consumption. See the introduction here.
Note: Prices are in Australian dollars ($AUD) and are estimates only - including all parts and labour for a hybrid solar or off-grid installation. An approximate cost breakdown is shown at the bottom for reference. The solar array size or number of solar panels required is based on an average of 4.5 PSH (peak sun hours per day), which is the average annual solar energy (irradiance) received around northern Victoria or southern NSW. Melbourne is approx 4 PSH, and Sydney is closer to 5 PSH. For locations further north in QLD, the requirements will be different as the energy use will be greater for air-conditioning in summer than heating in winter.
Solar & Battery System Price Estimate *
Basic Hybrid solar battery system for self-use: $10,000 to $12,000
Hybrid solar system for self-use with limited backup power: $12,000 to $16,000
Hybrid solar system for maximum self-use with backup power: $15,000 to $22,000
Hybrid/Off-grid solar & complete energy management system: $25,000 to $60,000
* Estimate only - full details and cost breakdown of each option below:
Solar and battery cost calculator
For more insight into the cost of solar and battery systems for your home, try the free solar and battery calculator. This tool will help you quickly calculate the optimum solar and battery system size for your home or business.
Basic Hybrid system for self-use
This is the most basic hybrid solar system with enough battery storage to cover peak evening energy use from 5pm to 10pm. The solar array will cover the majority of the daily energy use plus charging of the battery system. These systems use either simple hybrid inverters or small AC batteries, which are easier to install and are a great, cost-effective way to store solar energy. The main drawback is that they do not have backup power capability during a blackout.
Total energy used per day - 15kWh (over 24 hours)
Peak evening energy use - 4kWh (5-10pm)
Battery capacity required = 5kWh (usable capacity)
Solar array size* - Min number of panels required = 16 x 400W (6.4kW)
Location - Note slightly larger system is needed for southern VIC & TAS
Solar orientation - Roughly North facing on 20-30 deg tilt
Assuming no solar shading issues from large trees/buildings
Total estimated cost - $10,000 to $12,000 (inc GST)#
Inverter and battery options currently available - Solax, LG chem, Enphase, Sungrow, Goodwe, BYD, Huawei
2. Hybrid solar system for self-use and limited backup power
This is the most economical hybrid system with enough battery storage to cover peak evening energy use from 5pm till midnight. The solar array will cover the majority of the daily energy use plus charging of the battery system. These systems can also provide limited backup power during a blackout. Note, if the black-out happens during the day (when the battery is full) the system would typically be able to power essential loads (lights, TV, laptops, fridge etc) for 6-12 hours.
Total energy used per day - 15kWh (over 24 hours)
Peak evening energy use - 5kWh
Back-up reserve - 2.0kWh (after peak use)
Battery capacity required = 7.0kWh (usable capacity)
Solar array size* - Min number of panels required = 16 x 400W (5.2kW)
Location - Note that a slightly larger system is needed for southern VIC & TAS
Solar orientation - Roughly North facing on 20-30 deg tilt
Assuming no solar shading issues from large trees/buildings
Total estimated cost - $12,000 to $16,000 (inc GST)#
Inverter and battery options currently available - Redback Technologies, LG chem, Tesla, Pylontech, Alpha ESS, Fronius, BYD, Sungrow, Enphase, SolarEdge.
3. Hybrid solar system for maximum self-use and back-up power
This is a more advanced hybrid system with enough battery storage to cover your peak evening energy as well the off-peak overnight energy use. The solar array will cover most of the daily energy use plus charging of the battery system. These systems will provide greater back-up power during a blackout. Note, if the black-out happens during the day (when the battery is full) the system would typically be able to power your essential loads (lights, TV, laptops, fridge etc) for 12-24 hours or several days in good weather.
Total energy used per day - 15kWh (over 24 hours)
Peak evening energy use - 5kWh
Off-peak or overnight energy use - 3kWh
Back-up reserve - 2kWh
Battery capacity required = 12kWh (usable capacity)
Solar array size* - Min number of panels required = 20 x 330W (6.6kW)
Location - Note slightly larger system is needed for southern VIC & TAS
Solar orientation - Roughly North facing on 20-30 deg tilt
Assuming no solar shading issues from trees/buildings
Total estimated cost - $15,000 to $22,000 (inc GST)#
Inverter and battery options are currently available: Redback Technologies, Selectronic SP-PRO, SMA, LG Chem, Tesla, Pylontech, BYD, Sonnen, Fronius, SolarEdge.
4. Powerful Hybrid and off-grid solar systems
This is the most advanced system with enough battery storage to cover your total energy use for several days at a time. At the larger end of the scale, it is essentially an off-grid system and would be able to operate independently of the grid for much of the year and several days at a time over winter or bad weather.
These advanced systems use AC or DC-coupled solar arrays depending on the type of inverter/charger and battery system used. Generally, DC-coupled systems are used for smaller-scale systems up to 5kW, while larger systems use AC-coupled solar inverters, as shown below. AC and DC-coupled solar can be combined to form a reliable off-grid power system.
Note: If set up in an off-grid location, a backup generator would be required. Refer to the Going off-grid section below for more details about off-grid power systems. Also, see our guide to selecting an Off-grid/hybrid inverter and batteries here.
An advanced AC coupled off-grid solar power system with lithium battery bank - Click for full review.
The solar array and battery will typically cover all daily energy use plus charging of the battery system. In addition, these systems can provide full backup power for the entire home, including high-load appliances such as reverse-cycle air-conditioners. Note, if a black-out happens, the system would be capable of powering your essential loads (lights, TV, laptops, fridge, etc) indefinitely if you monitor the system and high loads such as air-conditioning for much of the day in the right conditions.
Total energy used per day - 15kWh (over 24 hours)
Peak evening energy use - 6kWh
Off-peak or overnight energy use - 3kWh
Back-up reserve - min 10kWh up to 30kWh or more.
Battery capacity needed = 20 to 40kWh (usable capacity)
Solar array size* - Min number of panels required = 24 x 400W (9.6kW)
Location - Note that a larger system is needed for southern VIC & TAS
Solar orientation - Roughly North facing on 25-45 deg tilt
Assuming no solar shading issues from trees/buildings
Total estimated cost - $25,000 to $60,000 (inc GST)#
Inverter options currently available - Selectronic SP PRO, SMA Sunny Island, Schneider Conext XW+, Outback Radian (USA only).
Battery options currently available include BYD, Powerplus, Pylontech, GenZ, Simpliphi PHI.
Low-cost DIY off-grid solar systems
Most small-scale (DIY) off-grid solar systems used on caravans, boats, small homes and cabins use simple solar charge controllers, also known as solar regulators, connected between the solar panel/s and battery. A good quality small 20A solar charge controller will cost around $120 and can be used with one or two solar panels. The job of the charge controller is to ensure the battery is charged correctly and not overcharged. These small systems often use 12V or 24V battery inverters to provide basic AC power, which are available in many different sizes, from tiny 150W inverters ($40) used for laptops and phone chargers, up to larger 3000W inverters ($1200) or even higher.
A small scale off-grid system used for DC lighting and simple AC appliances like phone/laptop chargers.
# Cost Breakdown - Solar battery systems
The following figures are a guide only - pricing from various distributors, installers and retailers can vary significantly depending on state and location. Prices in Australian dollars $
Hybrid solar Inverters - $2000 - $4000 (5kW Single phase)
Advanced Off-grid/hybrid (multi-mode) inverters - $4000 - $7500 (5 to 8kW per phase)
Battery storage - Lithium - $550 - $950 per kWh (usable)
Solar panels, including installation - $700 -$1300 per kW (inc solar STC rebates)
Note: Installation cost can vary significantly depending on roof type, roof height & available space, panel tilt kits, cable distance to the inverter, roof access, battery location, switchboard location and other requirements to meet current standards and regulations.
