Batteries
Home and commercial storage, battery-ready where it makes sense.
Residential
40kWh Battery
Forty kilowatt-hours is where batteries stop being a household accessory and start being plant. It suits farms, workshops, cafés, clinics and very large homes. This page lays out why the federal rebate looks modest at this size, and the questions worth answering before you commit.
- 40kWh usable
- NSW business incentive may apply*
01
What a 40kWh Battery Is Built For
- A rural property with pumps, cool rooms, sheds and a big house on one connection
- A small business whose heavy use runs into the late afternoon or evening
- A commercial site paying demand charges that a battery could trim
- A very large home with several EVs and a long list of electric appliances
If you are a normal household, start with the large battery size guide and see whether a smaller size fits.
02
What Shapes a 40kWh Battery Quote
Three-phase works, larger inverters, a heavier switchboard upgrade and cable runs on a large property can each move this figure. Commercial sites may also need protection relays or network studies.
03
Why the Rebate Looks Small at This Size
The federal rebate was redesigned in May 2026 to stop it paying out most heavily on the biggest batteries. Only the first 14kWh earns the full rate. The next 14kWh earns 60 percent. Everything from 28kWh to 50kWh earns 15 percent.
The practical point: at 40kWh the rebate is a nice contribution, but it is not what makes the project stack up. Usage and tariffs are.
Confirm the current rules with the Clean Energy Regulator.
04
Sizing From Real Data, Not Guesswork
- What is the biggest block of energy I use between solar sunset and sunrise?
- How high is my peak half-hour, and what does it cost me?
- How much of the battery would I cycle on a typical day, and on the worst day?
- What size of solar array would fill it?
Send us a bill or your interval data and we will run the numbers. We would rather tell you 30kWh is enough than sell you 40.
05
Large Home, Farm or Business: What Differs
| Large home | Farm | Business | |
|---|---|---|---|
| Main driver | Evening and EV charging | Pumps, cooling, long working days | Peak demand charges, trading hours |
| Typical supply | Single or three-phase | Often three-phase, sometimes long cable runs | Three-phase |
| State incentive | Not generally | May apply if registered as business | May apply (NSW) |
| Sizing data | Smart meter | Bills plus seasonal pump use | Interval data, tariff schedule |
06
The NSW Business Incentive
If the site is an NSW business, the battery may qualify for the Peak Demand Reduction Scheme incentive that opened for business batteries on 1 September 2026. The relevant activity covers batteries from 20kWh up to 200kWh (BESS4), with a higher rate when paired with new solar.
It sits alongside the federal rebate, but has its own eligibility rules and an accredited provider requirement. Details are on our NSW Commercial Battery Incentive page.
Scheme rules are published on the NSW Energy Sustainability Schemes site.
07
Power, Phases and Backup
A 40kWh battery with a modest inverter can store plenty of energy and still be unable to run your heaviest equipment. Check the continuous and peak kW ratings against your largest loads, such as compressors, pumps, welders and ovens. Confirm whether the system is single or three-phase, and decide whether you want automatic backup for the whole site or only for critical circuits.
08
When 30kWh or 50kWh Is the Better Choice
Choose the next size up only if your data shows you will use it. See the 30kWh and 50kWh pages.
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 40kWh Battery?
Large sites vary with phase, switchboard and network requirements.
02What Is the Rebate on a 40kWh 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 40kWh Worth It for a Home?
Rarely. It suits very large homes and sites with heavy loads. Most homes get better value from a smaller battery sized to their bills.
04Can My Business Get an Incentive for a 40kWh Battery?
If the site is in NSW, possibly. Business batteries from 20kWh to 200kWh can access a state incentive from 1 September 2026, alongside the federal rebate.
05Does the Battery Need Three-Phase Power?
Often, yes, or at least a three-phase-capable inverter. We check your supply before quoting.
06Can a 40kWh Battery Run a Farm in a Blackout?
Only if it is designed for it, with an inverter big enough for your largest loads and a backup configuration. We design to the loads you tell us you need to keep running.