If you live in the west of Ireland, chances are you’ve experienced power cuts that last longer than they should. Atlantic storms, fallen trees, salt air corrosion and long rural power lines mean electricity supply can be unreliable, especially in counties like Mayo, Galway, Sligo, Leitrim and Roscommon. For many homeowners, a backup generator is no longer a luxury – it’s peace of mind.
But one of the first and most confusing questions people ask is: what size generator do I need as a backup for my house? Buy one that’s too small and it won’t cope when you need it most. Buy one that’s too big and you may overspend unnecessarily.
This guide breaks it down clearly, using real-world Irish homes as examples, so you can choose the right generator for your needs.
Why Backup Power Matters in the West of Ireland
Power cuts in the west of Ireland are often caused by weather rather than faults inside the home. Strong winds, heavy rain and coastal exposure regularly damage overhead lines. In rural areas, restoration times can be longer because homes are spread out and access can be difficult.
For households relying on:
Electric water pumps
Oil or gas boilers with electric controls
Electric gates
Freezers full of food
Home offices or remote work setups
a power cut isn’t just inconvenient – it can be costly and stressful. That’s why understanding what size generator you need as a backup for your house is so important.
Step One: Decide What You Want to Power
The size of generator you need depends entirely on what you want it to run during a power outage. Not everyone needs to power their entire house. Most Irish homeowners choose one of three levels of backup:
1. Essentials Only
This is the most common option and usually the most affordable.
Typical essentials include:
Fridge and freezer
Lights
Internet router
TV or phone chargers
Oil or gas boiler controls
Well pump or water system
2. Essentials Plus Comfort
This covers daily living with fewer compromises.
In addition to the essentials, this might include:
Washing machine
Tumble dryer (occasionally)
Electric shower (short use)
Microwave or oven
Electric gates
3. Whole-House Backup
This is the premium option, often chosen for large rural homes or farms.
This may include:
Electric showers
Cookers
Heat pumps
Multiple freezers
Workshop tools
Home offices
Security systems
The more you want to run, the larger the generator you’ll need.
Understanding Generator Size (kVA vs kW)
Generators are typically rated in kVA (kilovolt-amperes), while appliances use kW (kilowatts). In simple terms:
1 kVA ≈ 0.8 kW (for most household use)
So a 5kVA generator can deliver roughly 4kW of usable power.
When asking what size generator do I need as a backup for my house, it’s important to think in total running load and starting load.
Running Power vs Starting Power
Many appliances use more power when they start up than when they are running. This is especially true for:
Fridges and freezers
Water pumps
Oil boilers
Compressors
For example, a fridge might run at 200 watts but briefly need 800–1,000 watts to start. Your generator must be able to handle these surges.
This is where many people in the west of Ireland get caught out by buying generators that are too small.
Typical Irish Home Generator Size Guide
Below is a realistic guide based on common household setups in rural Ireland.
Small Rural House (Essentials Only)
Fridge & freezer
Lights
Internet
Boiler controls
Recommended generator size:
👉 3kVA – 4kVA
This setup suits cottages, holiday homes or houses where power cuts are occasional and short.
Average Family Home
Fridge & freezer
Lights
Boiler
Water pump
TV & internet
Microwave
Recommended generator size:
👉 5kVA – 6kVA
This is the most popular size range for homeowners asking what size generator do I need as a backup for my house in the west of Ireland.
Larger Rural Home
Multiple freezers
Washing machine
Tumble dryer
Electric gates
Pumps
Home office equipment
Recommended generator size:
👉 7kVA – 9kVA
This gives breathing room and avoids overloading during peak usage.
Whole-House Backup or Farm House
Electric showers
Cookers
Heat pumps
Workshops
Multiple outbuildings
Recommended generator size:
👉 10kVA – 15kVA+
At this level, homeowners often consider permanent standby generators rather than portable units.
Portable vs Standby Generators
Portable Generators
These are moved into position when needed and started manually.
Pros:
Lower upfront cost
Flexible use
Ideal for occasional outages
Cons:
Manual setup
Limited power
Need safe outdoor operation
Portable generators in the 5kVA–7kVA range are very popular in the west of Ireland.
Standby Generators
These are permanently installed and start automatically when the power fails.
Pros:
Automatic operation
Can power the entire house
Seamless changeover
Cons:
Higher cost
Professional installation required
If power cuts are frequent or you rely heavily on electricity, a standby generator is often the best solution.
Fuel Type Considerations
When deciding what size generator you need as a backup for your house, fuel type matters too.
Petrol
Easy to source
Good for small generators
Not ideal for long outages
Diesel
More efficient
Better for larger generators
Common in rural Ireland
LPG or Gas
Cleaner burning
Long shelf life
Ideal for standby generators
Diesel generators are especially popular in the west of Ireland due to reliability and fuel availability.
Common Generator Mistakes to Avoid
Buying too small – the most common issue
Ignoring starting loads
Running everything at once
Poor ventilation placement
Skipping maintenance
A generator is only useful if it starts when you need it.
Generator Maintenance in Irish Conditions
The west of Ireland’s damp, salty air can be tough on machinery.
Good maintenance includes:
Regular test runs
Keeping fuel fresh
Checking oil levels
Protecting the unit from rain
Servicing annually
A well-maintained generator will last years and give confidence during winter storms.
Final Answer: What Size Generator Do I Need as a Backup for My House?
For most homes in the west of Ireland, the answer is simple:
Small homes: 3–4kVA
Average family homes: 5–6kVA
Large rural homes: 7–9kVA
Whole-house backup: 10kVA+
The right choice depends on your lifestyle, your location, and how much comfort you want during an outage.
If you regularly face long power cuts, live in an exposed rural area, or rely on electricity for heating, water or work, investing in the correct generator size is one of the smartest decisions you can make.
A properly sized generator won’t just keep the lights on – it keeps life moving when the weather turns against you.