Between bushfires, storms, and ageing infrastructure, blackouts are more of a risk to Australian homes than ever. It’s not enough to have a set of candles in the cupboard for “just in case” moments; you need solutions that don’t rely on the grid. If you are installing an off-grid solar system, you will have solved part of the problem – you also need the right backup generator to see you through inclement weather and other unexpected energy hiccups.
Why use diesel generators over other options?
Diesel generators are known for their superior fuel efficiency, durability, and reliability when compared with petrol generators.
- Fuel efficiency: Diesel engines generate more power per litre of fuel than petrol engines at equivalent load, meaning better fuel economy: longer runtime on the same volume tank, and lower operating costs in the event of an extended outage.
- Storage: Diesel has a longer usable shelf life than petrol – you don’t need to replace it as often if it is stored properly. Where petrol has a standard shelf life of 3-6 months, diesel can sit for 12-24 months in ideal conditions.
- Safety: Using diesel in generators is safer as it has a higher flash point than petrol, making it less prone to ignition during storage and handling. Bunded fuel tanks on diesel gensets will create a secondary containment layer as well, catching leaks before they become a problem.
- Engine life: Petrol generators reach a higher temperature than diesel counterparts. Wear and tear sets in faster, and ultimately, they have a shorter life span and aren’t suitable for high loads over extended periods. If you want reliable power and long-term use, diesel is a great choice.
- Operational noise level: Modern diesel generators feature noise reduction technologies like acoustic canopies, and can operate at much lower noise levels than older models or petrol engines.
What about battery-only backup?
Batteries are a normal part of backup for home solar systems, storing solar energy for when you need it. But sometimes you may find yourself caught short – such as during an extreme weather event, where you might not be able to generate enough solar energy to both support usual use and recharge solar batteries for nighttime.
Solar batteries are an important part of your system. However, good systems always have another layer of backup ready to go when you need it – and most homes will need more than a small inverter generator to see them through.
Related: What is the Best Off-Grid Solar Battery for Australian Conditions?
Diesel generators for home backup at a glance
No time to read the full article? Here’s a basic breakdown of our recommendations for home backup generators.
| Model | Best Situation | Prime Power | Standby Power | Engine | Std. Tank |
|---|---|---|---|---|---|
| DPS 13DF | Small home, shed or remote property | 12.5 kVA / 10.0 kW | 13.5 kVA / 10.8 kW | F2M2011 (2-cyl) | 50L |
| DPS 21DB | Average family home | 20.0 kVA / 16.0 kW | 21.5 kVA / 17.0 kW | F3M2011 (3-cyl) | 90L |
| DPS 33DB | Larger home, farm or workshop | 30.0 kVA / 24.0 kW | 32.0 kVA / 25.6 kW | F4M2011 (4-cyl) | 90L |
| DPS 44DB | Large property, working farm or home business | 40.0 kVA / 32.0 kW | 44.0 kVA / 35.2 kW | BF4M2011 (4-cyl turbo) | 90L |
Best generator for small homes: DEUTZ DPS 13DF Diesel Generator
Who this standby generator is suited for:
- Small homes with 1-2 bedrooms
- Weekenders or cabins
- Powered sheds
If you’re powering a small property or shed with essential appliances like a fridge, lights, security, and maybe one air conditioner unit, this compact and quiet option may be all you need.
Why we recommend it:
With a small footprint, quiet operation (just 63 dBA at 7m) thanks to the acoustic canopy, and a 50L bunded tank with an optional 600L bunded tank for extended use, DEUTZ have packed a lot of big features into this smaller model:
- 12.5 kVA prime power, 13.5 kVA standby power
- Powered by a DEUTZ F2M2011 diesel engine
- Low noise level with acoustic canopy
- Auto-start ComAp AMF25 controller (switches automatically when power fails)
With a reliable auto-start switch for when other power solutions fail and options for remote monitoring available, you can stay inside where it’s comfortable and let the ever-dependable DPS 13DF do all the work.
Best generator for family homes: DEUTZ DPS 21DB Diesel Generator
Who this standby generator is suited for:
- 3-4 bedroom homes running multiple circuits simultaneously
- Medium energy households supporting air conditioning, fridge, hot water, lights, home office etc.
Why we recommend it:
The DPS 21DB is a step up from the smaller 13DF in terms of load. It has the same domestic-friendly acoustic canopy for silencing, and an automatic start to ensure it can kick on in the middle of the night if needed – without waking the house.
Features include:
- 20 kVA prime power, 21.5 kVA standby power
- Powered by a reliable DEUTZ F3M2011 diesel engine
- 90L standard bunded fuel tank with optional 600L bunded tank
- Robust canopy for silencing and environmental protection
- Auto-start ComAp AMF25 controller (switches automatically when power fails)
Best generator for large homes: DEUTZ DPS 33DB Diesel Generator
Who this standby generator is suited for:
- Large homes or multi-use properties like hobby farms
- Properties with significant electrical demand beyond the essentials: multiple AC units, bore pumps, workshops, machinery
Why we recommend it:
The DPS 33DB is built for properties where power demand goes well beyond the basics. Whether you’re running multiple air conditioning units, a bore pump, workshop equipment, or simply a larger home that can’t afford to shed load during an outage, this unit handles it.
Features include:
- 30 kVA prime power, 32 kVA standby power
- Powered by a DEUTZ F4M2011 diesel engine
- 90L standard bunded fuel tank with optional 600L bunded tank
- Acoustic canopy for quiet, weatherproof operation
- Auto-start ComAp AMF25 controller (switches automatically when power fails)
Best for large properties, farms, home-based businesses: DEUTZ DPS 44DB Diesel Generator
Who this standby generator is suited for:
- Large, busy homes or properties with multiple dwellings
- Working farms
- Multi-use properties with a home, workshop, cool rooms, irrigation, or other heavier load equipment that can’t go offline
Why we recommend it:
The DEUTZ DPS 44DB is a seriously powerful unit for large homes or mixed-use properties, like working farms or home businesses. When your time is money, this generator helps you avoid losing either with seamless backup capability.
Features include:
- Large capacity 40 kVA prime power, 44 kVA standby power
- Powered by a DEUTZ BF4M2011 diesel engine
- 90L standard bunded fuel tank with optional 600L bunded tank
- Quiet operation with heavy-duty acoustic canopy to help silence and protect from the elements
- Auto-start ComAp AMF25 controller (switches automatically when power fails)
How to choose the right size generator
To choose the right generator for your specific needs, first determine all the appliances you want to power simultaneously and their total power requirements in watts. For example, common household appliances might use:
- Fridge / freezer – 150–400W running (higher on start-up)
- Air conditioner (split system, 2.5–3.5kW) – 800–1,500W running; 2,000–3,000W start-up surge
- Washing machine – 500–1,200W (higher if heating water)
- Dishwasher – 1,200–2,400W
- Electric oven/stove – 2,000–5,000W
- Desktop computer and monitors -200–600W
- Electric hot water system – 3,600–4,800W
- Medical equipment (e.g. CPAP) – 30–200W
You will need to check the appliances you own for precise information as this varies between configurations and manufacturers.
It’s important to consider both the starting and running power requirements of appliances. Many things require significantly more power to start up than to run continuously – sometimes up to 3 or 4 times the running watts.
Then, you need to match this information to a high-efficiency generator. Generator sizes are typically given in kVA (kilo-voltamps), which can be converted to watts by multiplying by 0.8 to account for the power factor.
Do you need an automatic start function?
The ComAP AMF25 controller on these models gives you peace of mind by ensuring you will always have a dependable power output, without having to manually turn anything on.
If you’re away, busy or sleeping, you might not realise the grid or your solar system has stopped working for a while. Generators with the ComAP AMF25 Controller ensure uninterrupted power to your essential appliances and any other equipment that needs to run without end, because they are designed to switch on precisely when you need them. The days of losing the contents of your freezer because of a power outage can be well over with the right system and home backup generator.
Does phase matter?
Yes, because it affects how steady the flow of power will be during continuous operation. Three-phase units tend to be steadier, quieter, and have a longer lifespan than single-phase generators.
All of the gensets we have listed above have three-phase systems. This means they’re electric generators that produce three alternating currents (AC), which are offset from each other by 120 degrees. The power is delivered in three overlapping waves, so the flow never drops to zero – much more efficient and versatile for heavy-duty or continuous operation than single-phase units.
Avoid “never again” moments with reliable backup power
Everyone’s had that moment: where everything went wrong and you were left without a power supply at a crucial moment. Whether you just need to keep the essentials humming or have a larger operational load, having a reliable diesel generator is the key to making sure the lights stay on when you need them most.
Finding the right home backup generator isn’t just about selecting the most powerful one in every situation; for example, the DPS 44DB is perfect for multi-dwelling properties but would be overkill for a 1-2 bedroom house. You need to find the right one for your energy needs. If you’re still not quite sure what that involves, why not get in touch for expert advice or request a quote based on your current power needs. We can match you with the right generator for your set up, with free shipping available Australia-wide.
