Batteries
Home and commercial storage, battery-ready where it makes sense.
Residential
20kWh Home Battery
For homes that outgrow the standard battery: more people, more electric cars, more air conditioning. Twenty kilowatt-hours covers a heavy evening and most of the night. See who it suits and how to tell if it fits.
- 20kWh usable
- Suits large homes, EVs and small business*
01
A Quick Word on 20kW Versus 20kWh
"20kW solar battery" is one of the most searched terms in this category, and it is a muddle. A solar array is measured in kilowatts (kW). A battery is measured in kilowatt-hours (kWh). This page is about a 20kWh battery: the amount of energy it stores. For array sizes, see our solar and battery packages.
02
What Shapes a 20kWh Battery Quote
If you have no solar yet, or the inverter you have cannot talk to a battery, assume the higher figure. Three-phase upgrades, switchboard work and brand choice all move it.
03
How the Tiered Rebate Treats 20kWh
The first 14kWh earns the full federal rate. The remaining 6kWh earns 60 percent of it.
Confirm the current rules with the Clean Energy Regulator.
04
How an Electric Car Changes the Maths
Most of the households asking about 20kWh own an EV, so it is worth doing the sums properly.
Many EVs use somewhere between 15 and 20kWh to travel 100km. Check your own model's figure. If you drive 40km on a normal day, that is roughly 6 to 8kWh to put back overnight. Add a heavy evening for the house, and the total passes 15kWh quickly.
Illustrative ranges, built from assumed daily driving and household loads. Your own bills and driving decide.
A second option is to charge the car in the middle of the day from the panels. If someone is home, or the charger can be scheduled, the car can soak up midday solar and the battery can stay smaller. See EV Chargers.
05
Who Should Choose 20kWh
- A large home with ducted air conditioning, a pool and one or two EVs
- A house where several people work from home
- An owner who wants real backup capacity as well as bill savings
- A small business with a modest overnight load, such as a café's cold room or a small clinic
Not sure? A good test is your lowest-priced use of power. If you would still be buying expensive grid electricity at 10pm and again at 6am with a 15kWh battery, 20kWh may be worth the extra. If a 15kWh battery would still be half full at sunrise, it will not.
| Household | Evening and overnight need | Fits |
|---|---|---|
| Large family, no EV | 12 to 15kWh | 15kWh, possibly 20kWh |
| Same family, one EV charged overnight | 18 to 23kWh | 20kWh |
| Two EVs or heavy daily driving | 25kWh or more | 30kWh, or charge on a cheap grid tariff |
06
Backup Power at This Size
At 20kWh the capacity is rarely the limit. The power rating is. A battery that can deliver only 5kW will hold plenty of energy but cannot run the oven, ducted air conditioning and an EV charger at once.
Ask for both the continuous and peak kW ratings, and decide which circuits you want kept on. Backing up an oven or ducted air conditioning is a bigger design job than backing up the fridge, lights and internet, and the scope depends on inverter output and switchboard configuration.
07
Is 20kWh Better Than 15kWh or 30kWh?
Twenty kilowatt-hours is where the rebate starts to taper noticeably, but it is still a strong size for homes that need it. Above it, each extra kilowatt-hour earns less rebate. See the 15kWh battery and the 30kWh battery.
08
Small Business Sites
20kWh is also where the NSW business battery incentive starts. From 1 September 2026, eligible NSW business sites can access an incentive on batteries from 20kWh to 200kWh, in addition to the federal rebate. The rules differ from the residential scheme, so check the details on our NSW Commercial Battery Incentive page.
Equipment
Battery Brands We Install
We fit storage from manufacturers with local support teams, so the warranty on your battery still means something in ten years.
Brand availability depends on your system design and location. We confirm the selected equipment and manufacturer warranty in your written quote.
Important Information
* Rebate details, output figures and timeframes shown are indicative estimates based on stated assumptions, not an offer, quote or guarantee. Your outcome depends on your site, roof, switchboard, network, products and the date of installation, and your written quote prevails. Savings and payback are not guaranteed. See clauses 24.1 to 24.5 of the Terms and Conditions.
Questions
Common Questions
01What Affects the Quote for a 20kWh Battery?
Your written quote is confirmed after your assessment*.
02What Is the Rebate on a 20kWh Battery?
It depends on your home, your site and the equipment you choose, so we confirm it in a written quote after a free assessment.
03Is 20kWh Too Big for a Home?
For most homes, yes. It suits large households, EV owners and sites with heavy overnight loads. If your evening use is under about 14kWh, a smaller battery will serve you better.
04How Long Will a 20kWh Battery Run My House?
Divide 20kWh by your average load. At 1.5kW it lasts about 13 hours. At 3kW, about 6 and a half hours.
05Does 20kW Mean the Same as 20kWh?
No. kW is power and kWh is stored energy. A 20kW solar array and a 20kWh battery are different products.
06Can a 20kWh Battery Be Added to Existing Solar?
Often. It depends on the inverter. Tell us what you have in the quote form and we will check it.