what generator size do I need for my house

What size generator do I need?

Choosing the generator size to suit your application can be tricky

Generators are an excellent investment and are called upon in a variety of different situations where power sources are simply insufficient or unattainable. Generators are also useful during a power outage. They can prevent discontinuity of daily activities or disruption of domestic, business and recreational operations. 

A generator can save you a lot of frustration and stress, especially if you find yourself without power during periods of severe weather. However, not all generators are created equal, with each type containing different characteristics, adhering to different levels of power needed.

Since a generator is the first line of defence against such problems, it can be difficult to understand which one is best suited for you and your needs. To help we have laid out a guide to help you determine which generator is best for you.

Determining your peak wattage needs

Firstly, it is important to calculate and determine your peak-wattage needs. It seems obvious, but you must determine how much power you need. 

  1. Make a list of what appliances you need powered in the event of a power outage.
  2. Determine the starting and running wattage of each appliance.
  3. Add up the total wattage needed and base the generator size you need on this number

When choosing a house generator look for a generator that has a peak output higher than the number calculated. If you undersize, the generator will struggle to meet the electrical demand.

The size of the generator is dependent on the number and type of electrical appliances you plan to run. Cooling and heating appliances like fridges, heaters and air conditioners consume the most power. Therefore you will need a bigger, more powerful generator. Whereas, if you are wanting to provide power to the lights in your home, opt for a smaller generator.

Moving appliances like pumps and fans require a stronger electrical current. Therefore consume a lot of electricity at the start up but don’t require a lot of power to continue functioning. These are the types of questions you should be asking yourself before purchasing a generator. 

Backup power for your house

Convenience and comfort for your family 

The most common and compelling reason people invest in generators is to provide comfort and convenience to their loved ones. Homeowners can face a long list of inconveniences and expenses when faced with an unexpected power outage. From spoiled food and frozen pipes to mouldy walls and flooded floors. 

Power outages can be incredibly stressful, so by having a generator on standby, you can have peace of mind. 

Extreme weather conditions

Grudge has a range of generators best suited specifically for providing back up energy during emergency situations. 

If you live in an area that is susceptible to severe climate or weather conditions and need an emergency energy supply, we recommended the Grudge range of 6-9kVA. For families who live in coastal areas, where storms and strong winds pose as a threat, having a backup generator can enable them to monitor the latest news and weather updates. Therefore, providing a sense of security and safety. 

Rural and Agricultural Areas

When living in rural areas, electricity is heavily relied on, therefore having permanent power is incredibly important. For example, a farm without a power is a farm at major risk and therefore a generator is a necessity in these agricultural sectors. In order to prevent a disruption we recommend using a Grudge 12-14 kVA in rural areas. Not only will it provide a great, long lasting circuit of electricity, but it will prevent the repercussions associated with having no energy source.  

Generators for Business, Commercial and Contractors


In the case of a power outage, it is important to minimize the downtime that your business endures. The last thing you want is for everyone to panic or for things to go erratic due to an unpredicted power outage. Therefore, it is important to have a backup supply in place to ensure the continuation and operation of your business. A back up 6 – 9 kVA Grudge generator can help you stay in communication with your customers and keep providing service to them. A generator can help in backing up important files in the cases of unpredicted power cuts and also serve as a protective element to prevent power cuts from damaging hardware.

For businesses, we strongly recommended investing in an Grudge diesel or petrol generator to help keep your business operating in the event of a power outage. Whether you are a small enterprise, market stall, butcher shop, restaurant etc the Grudge range of generators can help keep your business pumping during these times of insufficient power. 


When working on a construction site, having a sufficient supply of power for contractors and workers, is incredibly important. Contractors can find themselves working on many buildings where the main power supply has not been connected. Therefore heavily rely on the power supply from generators to operate their tools. With the backup power from a Grudge 14kVA Diesel or 12kVA Petrol generator, contractors can power the necessary equipment needed to undergo their daily tasks. 

Outdoor and Recreational Events

Festivals, Concerts and Celebratory events 

Outdoor and recreational events require a sufficient supply of energy. With many festivals, concerts and celebrations located in rural areas and lasting for many hours, it is important that there is a strong electrical supply. Wedding venues and other large catering events require generators in order to power electric ovens, fans, fridges and freezers. While recreational events like festivals require lighting rigs and sound systems. The Grudge 14kVA Diesel or 12kVA petrol generators are the 2 most recommended for these purposes. They can provide a sufficient supply of power for a longer duration of time.

Camping and Caravanning

If you are heading out on a camping trip over the holidays and want to keep your food chilled, and maybe even brew a nice cup of coffee, bringing along a generator can make this possible! Portable generators are ideal for camping and caravanning as they provide backup power to the conveniences of modern living. Such as; electric stoves, mini fridges, and they can power smaller appliances such as mobile phones, microwaves, showers and air conditioning. With the 3 kVA Grudge generator, you can bring and hook up appliances like a fan, microwave, mini fridge all while enjoying the tranquillity of the great outdoors. 

So YES Generators are an INVESTMENT!

We can sometimes forget how useful generators are. After all they are most appreciated in the event of a power outage! Whether you need one for your home, business, wedding, camping or for agricultural use, generators can power a strong electrical current to a wide variety of appliances. Be sure to pick the generator most suited to you and your needs. Gain adequate power from a diesel generator, petrol generator or house generator to a silent generator or portable generator.

Browse through our range of generators by clicking here and see which one is best suited to you!