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Choosing an Off-Grid Generator in 2021

Anyone planning to install an off-grid power system in the UK must also ensure they’re taking into account how much sunlight and wind is available throughout the course of the year.

Complete energy independence means establishing the ability to generate the required energy no matter the conditions, which is where an off-grid generator comes into play.

There are a few different options available when choosing the right backup generator for an off-grid system, which is what we’ll be taking a closer look at in today’s piece.

Why Would Someone Need Off-Grid Power?

Modern systems offer a dependable, economical and a superior power source for businesses and homeowners in need of consistent power off-grid.

The flexibility to customise off-grid energy systems is a crucial factor in how someone will select the right system for their needs.

Someone may choose off-grid power systems for a variety of reasons, including:

  • The location of the property makes grid connection too expensive or simply not possible.
  • A requirement for consistent, uninterrupted power where power cuts are a frequent occurrence.
  • Desire to maximise renewable energy sources.
  • Preference to utilise greener initiatives.
  • Adaptable and expandable power requirements.

Explaining Off-Grid Living

Living off the grid is simply a lifestyle choice for many, yet an economic necessity for others. Even in many developed western countries, the grid simply isn’t capable of reaching everyone, and the prospect of connecting to the grid – as we covered in this blog – can be incredibly expensive.

Many property owners achieve independent living by installing fuel generators to supplement their energy requirements.

These can either be variants that can run continuously or can be turned off overnight. Overnight power can either be turned off altogether, or small loads utilising energy from battery inverters can be used to heat central heating or keep fridges running, for example.

Although modern systems are incredibly efficient, it’s important to bear in mind the cost of fuel and the maintenance costs required when a generator runs over long portions of the day.

This is precisely why selecting the right off-grid generator is such a difficult and important decision.

When you’re making your choice, it’s important to be realistic about potential power usage at peak times. Trying to save money and under estimating requirements from the system will result in power outages and higher, often unnecessary fuel costs.

Do I Need a Generator for My System?

A good generator will be your Plan B on those days where there isn’t much natural light or wind power to generate enough energy for your requirements.

Of course, not every solution will need a generator, but here in the UK if you’re living or working within an off-grid property, a generator is a good way of ensuring your batteries are charged, and you’re always guaranteed the power output you need to live and work.

As we’ve already mentioned, you could use a wind turbine as a secondary power option, but in situations where this is neither practical nor possible, a generator just makes good sense.

What Kinds of Generators Are Available?

There are two typical kinds of generator available: conventional generators and inverter generators.

Conventional generators – are used anywhere where a portable energy source is required, such as on boats. These are relatively cost-effective and easy to maintain. The downside though is that they don’t supply a consistent flow of energy, and they can be noisy and dirty to run.

Inverter generators – are more advanced and can deliver consistent and refined energy to better suit home appliances and electronic devices. They are also almost silent and incredibly efficient when it comes to fuel use. Although they are more expensive than a conventional generator, they will offer more substantial fuel savings over the course of their lifecycle.

Backup Generator Fuel Options

In most cases, generators run on either diesel, petrol, natural gas or propane.

Diesel – is readily available, relatively safe and highly efficient. However, bear in mind that diesel does have a limited shelf life, and the generator will require heavy fuel loads to work at its best.

Petrol – while petrol is as accessible as diesel, it is far more flammable. It too has a limited shelf life, but storage will need to be considered very carefully.

Propane – is much cleaner and quieter than either diesel or petrol, but isn’t as readily available. It’s also more expensive to purchase, and burns faster than the previous two options, therefore rendering it more inefficient.

Natural Gas – is also clean and quiet, when compared to diesel and petrol, yet it also has the added bonus of performing far better in cold conditions. That said, natural gas generators are heavy on fuel and far more expensive to purchase.

Automatic vs Manual

Another thing you must consider when selecting a generator is the mode of support. In other words, do you need an automatic system or a manual one?

Automatic Generators – are integrated into your off-grid system and will kick into action once the battery power levels are draining or when the draw on the system is higher than usual. Automatic systems are most commonly used to either charge the batteries or provide supplementary power in high load scenarios.

Manual Generators – as you’d probably imagine manual generators must be started by hand when they are needed. The upside to this though is the fact that these options are far cheaper, and are often installed in business premises, where someone would just turn them on in the morning and off again at night.

Generator Size

When looking for a generator, the physical size is of little consequence in most situations. When we refer to ‘size’, we’re actually referring to how much wattage capacity it can deliver and how much energy it can generate for an off-grid property.

In order to calculate the size of your generator, you’d first need to know the power requirements of your off-grid system.

A standard backup generator for an off-grid property will ideally need to produce double the wattage that your inverter would. For instance, if you’re using a 24v inverter that can manage a continuous load of 650w, then you’d need a 1300w generator and so forth.


Selecting a generator to supplement your off-grid system is one of the many decisions that will require careful consideration when you’re putting together an ideal solution for your needs.

If you’d like to like any more advice about generators or off-grid power, or you’d like to learn about any of our other products or services, then why not contact us today for more information?

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