Generators vs UPS Systems – Which is Better?

The roles that a generator and a UPS play in powering electrical equipment for everyday businesses is often critical. When it comes to getting a guaranteed power supply, there are only really two main options. Whilst both generators and UPS systems provide essential backup when the power goes out, the two have various functions and can be used in different ways.

Whether using a generator or UPS system on its own or installing them together so they work in tandem, finding the right working combination for your organisation or business will successfully protect against power interruptions.

Having a generator and UPS work together can provide robust protection, although implementing both a generator and UPS into your workspace can be quite costly. Dependent on the industry you are working in, there are many pros and cons to running the two power supports in your workspace.

Here’s some information on both:

UPS – Uninterruptable Power Supply Systems

An Uninterruptable Power Supply or UPS is a battery-operated device that provides instant back-up for critical electrical equipment in the event of an outage. A UPS powers on automatically, keeping appliances running without interruption.

Designed to fill the gap between the outage and before the generator kicks in, a UPS offers a seamless transfer of power. As a battery-operated device, and unlike a generator, a UPS only has a few minutes of power supply. During this time, this type of power support will offer critical protection against power surges or outages.

The benefits of having a UPS running alongside a generator is that it can give you sufficient time to power down critical equipment properly and save data. When the power goes down, the transfer of power is instant, unlike a generator which may take a few minutes or longer to kick into action, potentially causing failure to critical equipment and causing data loss.

Different types of UPS systems

There are three types of UPS systems including Online Double-Conversion, Line Interactive and Offline or Standby.

Online Double-Conversion

Online Double-Conversion UPS is when incoming power is converted to Direct Current or D/C and then converted back to A/C. This type of power is continually working, rather than jumping into action when there is a power outage. Offering a constant run of stable power, this type of UPS does cost more to run as it works to maintain a consistent current flow to protect network equipment.

Line Interactive

A Line-Interactive UPS adds an auto-transformer to the basic standby UPS. It has the capability for increasing or decreasing the voltage output. Compared to the other types of UPS, it offers a more middle-ground solution as it has more operating modes. For example, from economy-mode and double-conversion mode to active mode, this type of system will automatically decide the best solution for the situation at hand.


An Offline or Standby UPS works by more of an intervention in terms of its power supply. Rather than continually cycling energy, an Offline UPS detects abnormalities or disruptions in the regular power source and is designed to kick in on detection. It works by directly supplying the power to the A/C load from the A/C mains, using an inverter to power the A/C load from the D/C battery.

This type of UPS is best suited to a non-critical and less-demanding home network and office environment, with equipment under 1kVA.


A diesel generator is renowned for its significant power output capabilities. As well as providing vital back-up power for many industries, as a general rule they excel in performance and offer an unparalleled high output. With most diesel generator often having large fuel tanks, they are also able to run for long periods of time without the need for frequent refuelling.

In comparison to a UPS, whose power supply comes from the A/C mains, a generator coverts mechanical energy into its own power. Vitally, diesel generators offer back-up power that can last indefinitely. As well as being more economical for larger businesses and organisations looking for a fault free power supply, they also come with added efficiency and reliability, with diesel itself very often being a more suitable choice than other fuel types.

Whilst a diesel generator offers good economy for heavy usage, there are generators and fuel types to suit a variety of situations. Compared to a UPS, the customer has more generator options to choose from.

With the added advantage of running uninterruptedly for longer periods, sometimes up to weeks at a time, diesel generators lend themselves to heavier industrial use. The diesel generator is a very efficient machine, offering a cost-effective solution for many larger industries.

However, with this comes the additional need for that extra level of attention. Suffering less wear and tear than petrol-run models, regular generator maintenance will be required to ensure all components are in full working order.

Other things to consider…

  • Does your workspace require an emergency generator? If so, are the generators routinely maintained/tested and relevant staff adequately trained?
  • How will security systems operate during a power cut? Do they have a battery life, or will they need resetting?
  • Do you need a contract in place for emergency security staff?
  • Do you need an alternative lighting supply? Are you 24/7 or can you survive without lights for a short time? Consider areas such as exits, stairwells, outside and where your meter is.
  • Could you install surge protection devices to protect sensitive electronic equipment?
  • Within your workspace, are there any team members dependent on lifts? Do you have evacuation chairs?

Dependent on your work environment, getting your workplace ready for such eventualities will pay in the long run. For larger workplaces, it may also be worth considering rehearsing for an electrical outage so that your workforce understands what to do.

With every business operating differently, it can be an invaluable process to put together your own personalised checklist of considerations. With your own tailored checklist, you can be more in control of what and who may be affected and any alternative measures that can be put in place beforehand.


As soon as the power goes down, you will need to establish whether the outage is a local problem or one affecting your business setting only. Either way, the following checklist will provide you with some active measures that will help minimise disruption.

Consider the following…

  • Can you restore power by operating your trip switch?
  • Has something caused your internal systems to trip, and if so, do you need to call an electrician?
  • Where is/are your electricity meter(s)?
  • Contact your network operator to report the outage.

Once you have established that a power cut has taken place, reporting it on 0800 6783 105 or 105 will ensure the outage has been logged straight away. Once you have adopted these simply measures, you may also wish to visit your own Distribution Network Operator’s website for more information and for further ways of keeping in touch.


Protecting your business and keeping disruption to a minimum will be high up on things-to-do during an outage. By considering your IT and other electrical equipment, you can really help protect your space so that when the lights come back on, you will have taken the correct measures to preserve as much of your workspace as possible.

  • Have you shut down unnecessary equipment?
  • Will any equipment need to be considered for a controlled reset or restarted in a controlled order when power is restored?
  • Do you need to switch off breakers on equipment that could cause a surge when power is resumed?
  • If you use an emergency generator, do you need to order fuel?
  • Do you need to inform suppliers, customers or anyone else that you are without electricity?
  • Do you need to consider staff welfare issues, e.g. heating, water and food?
  • Consider vulnerability of disabled staff. Are they on upper floors? Do they need to be at home?

When thinking practically about your IT, it can be useful to know how long you can manage without sufficient power to your workplace.

Computers, iPads etc. will all have a certain amount of battery life before they drain down.

Do you have an IT Disaster Discovery Plan? Does it back up your data effectively to the Cloud and how often will it provide this back-up?

With many areas to consider, you may wish to save the following contact details so that you have instant access to the right support services.


If you’re currently in the middle of a power cut, you can use our postcode checker to find out the projected end time. Alternatively, you can report a power cut by calling 0800 6783 105. If in doubt, call 105.

WBPS – Your Diesel Generators and UPS Specialist

At WBPS, whatever your requirements, we believe your generator and UPS systems are at the heart of your operations. As suppliers of critical power solutions for over 40 years, we are also the UK’s largest distributor of Kohler-SDMO generators and well-equipped to help you with all your generator needs.

Suppliers of a wide range of services, including equipment for hire, sale and maintenance packages, we can ensure whichever package you choose we will help keep your unit in good working order. From single generators rated at 6kVA to 4500kVA, to UPS systems we can select and install the right equipment into your current business process with minimal disruption to the daily running of your site.

To keep your investments running in full working order, WBPS also provide a range of maintenance contracts to suit all businesses and budgets. All our maintenance projects are undertaken by teams of experts including Engineers, Project Managers, Consultants and Logistics Coordinators, all of whom are directly employed by us.

To find out more about the services we provide or to speak to one of our experienced team members today, please get in touch to see how we can help you and your organisation.


Send this to a friend