Blog
Are you currently planning to reduce your site's carbon emissions? Then you might have already considered switching your backup generator to hydrotreated vegetable oil (HVO) fuel.
With up to a 90 per cent reduction in lifecycle emissions compared to regular diesel, HVO can seem like an easy win. So why would businesses hesitate to switch? The usual reasons we hear are cost and fears over reliability. Your generator might only run a few times a year – but when you need it, it simply has to work.
The good news is that HVO can be a suitable alternative to diesel for many generators. There are a few things worth checking first, though. In this blog, we'll look at how to decide whether HVO is right for your site.
HVO is a renewable alternative to conventional diesel. It can be made from materials such as used cooking oils, vegetable oils and animal fats. This produces a fuel with properties similar to fossil diesel but with much lower lifecycle emissions. HVO that meets the EN 15940 standard can be used in many approved diesel engines – including standby generators.
In this way, HVO can help businesses cut overall carbon emissions. Another major benefit is that HVO is less prone to degrading than other fuels. This can bring extra peace of mind in terms of fuel management, especially if you store it for long periods.
There are signs of growing confidence in HVO across the UK. For example, London Fire Brigade began using HVO in vehicles and standby generators in 2024. In 2025, it reported substantial estimated carbon savings of around 600 tonnes.
One of HVO's biggest attractions is its potential to reduce greenhouse gas emissions. But by how much? As we’ve seen, depending on how the fuel is produced, HVO could bring lifecycle emissions savings of up to around 90% versus diesel.
But what does this mean for your business in reality? Importantly, it doesn’t mean that emissions from an exhaust contain 90% less CO₂ than diesel. Instead, lifecycle emissions take into account HVO’s:
Production
Transportation
Actual end usage.
If you're considering HVO for its sustainability benefits, ask your supplier for evidence of the origin and carbon savings. This will tell you by how much HVO could improve your sustainability.
In many cases, HVO can be a drop-in fuel for your existing generators. However, it’s important to check your manufacturer's guidance first. This will help you understand whether your current generator is suitable and whether any preparation is needed. If you’re running older equipment, the answer might be less straightforward.
If you're changing an existing fuel supply, it's always best to check the condition of your tank and stored diesel first.
In most cases, HVO performs as well as conventional diesel. However, there can be small differences in fuel consumption. Some engines may use slightly more HVO by volume – between two to seven per cent more, according to a recent study. It’s important to factor this into any cost comparison.
HVO can also give you good storage stability and cold-weather performance. This is useful if your generators spend long periods on standby. Of course, water, contamination and poor storage conditions can still cause problems, so you should still run regular checks and servicing.
With its excellent potential to cut carbon emissions, you might wonder why HVO hasn't replaced diesel more widely. We usually hear three main reasons.
The main concern is usually cost. The price difference varies based on world events and time of year. HVO fuel prices vary – they can sometimes be similar to diesel, and sometimes higher. You’ll need to balance these factors against your sustainability goals.
The next concern is usually how tricky switching will be. Your equipment may need work before switching to HVO. This depends on the generator, fuel system and condition of the tank. Some manufacturers allow switching without cleaning, while other systems may need preparation. An inspection can help you decide what work – if any – is needed.
Finally, the availability of HVO versus diesel is another consideration. Diesel has a huge, well-established supply network. Meanwhile, HVO supply can vary depending on where your site is based. It’s best to make sure you can get a reliable supply of HVO before you commit.
If the benefits of HVO outweigh the challenges for your site, how can you get started? There are a few simple checks worth making first:
Confirm whether your engine manufacturer approves HVO and any conditions that apply
Inspect tanks, pumps, pipework and filters for any signs of wear or contamination
Check if tank cleaning may be recommended before switching
See if you can get reliable deliveries when you need them
Find out whether changing fuel would affect your ongoing manufacturer support.
Changing fuel might be daunting, especially when your business relies on backup power. But once you’ve carried out these checks, you’ll have a good idea if HVO could be a good option for your site.
At Dale Power Solutions, we know that all critical power needs are unique. That’s why we help businesses choose and maintain backup generators that suit their individual site requirements.
If you’re considering switching to HVO, our team can review your existing setup and assess the condition of your fuel system. We can also help with new generator projects, fuel management and ongoing maintenance. Contact us to learn more about your options.
