Low carbon fuels (LCF)
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While service delivery and road safety are important to freight operations, fuel is a resource that needs to be well managed. Vehicle emissions can have a serious adverse impact on public health and climate change. Although fuel use varies considerably across different fleets, it nevertheless represents a major cost in most settings. In many operations, fuel can account for 30% or more of total operating expenses.
The Renewable Fuels Assurance Scheme (RFAS) has been developed by Zemo Partnership to enable vehicle fleet operators to have independent assurance of the greenhouse gas emission and feedstock sustainability performance of high blend renewable fuels sold in the UK. Learn more about the Renewable Fuels Assurance Scheme (RFAS). Learn more about the Renewable Fuels Assurance Scheme (RFAS).
Adopting low carbon fuels
Burning fossil fuels such as conventional diesel can have a serious adverse impact on public health and climate change. Adopting low carbon fuels offers a viable route to lowering greenhouse gas (GHG) emissions in the short to medium term as they provide a flexible alternative to fossil fuels in hard to decarbonise modes such as road freight. Long and regional duty cycles would benefit the most given their high mileage, energy requirements and consequently their fuel consumption.
Low carbon fuels are fuels that deliver greenhouse gas savings on a life-cycle basis compared to fossil fuels, for example biofuels or other renewable fuels such as renewable hydrogen. Biofuels are produced from biological raw materials (so-called feedstocks), such as energy crops or organic waste. When biofuels undergo combustion in a vehicle, tail-pipe CO2 emissions are accepted as net-zero. This is because the CO2 must first have been taken out of the atmosphere by plants during their growing process. However, biofuels still contribute to local air pollution and operators must consider any CO2 emissions associated with the biofuel supply chain. This guide concentrates on the biofuels that can be used in current vehicle fleets as “drop-in” fuels. The Renewable Transport Fuel Obligation Order (RTFO) is the UK Government’s mechanism to reduce GHG emissions from fuels. The RTFO requires biofuels to meet stringent GHG emissions and sustainability standards. In 2022, 93% of biodiesel supplied under the RTFO was produced from wastes.
Currently, most low carbon fuels, mainly biofuels, are blended at low levels into standard petrol and diesel available at public refuelling stations (i.e. B7=up to 7% biodiesel, E10= up to 10% ethanol). Fuels with a higher biocontent and other low carbon fuel options can offer additional carbon savings but may require adaptations to vehicles, refuelling infrastructure and servicing.
Although some modifications may be required depending on the fuel type and the manufacturer, it means existing vehicles can be used in some cases.
Many organisations now incorporate standards for low carbon vehicles and fuels into their procurement processes.
The following factors should be considered when assessing the suitability of LCFs:
- Operational: vehicle compatibility, fuel storage and refuelling infrastructure.
- Financial: on a total cost of ownership (TCO) basis and factoring in annual mileages.
- Environmental: fuel and feedstocks to comply with the RTFO sustainability criteria; make use for example of the Renewable Fuel Assurance Scheme.
The following sections provide more detailed information on the key specific types of LCFs available to freight transport operators.
Biodiesel
In the UK biodiesel, mostly in the form of FAME (Fatty Acid Methyl Esters), is predominantly made from waste-based raw materials such as used cooking oil (UCO) or tallow (rendered animal fat).
Biodiesel has similar properties to fossil diesel and is already present, as a small percentage, in regular diesel purchased at public forecourts (known as B7 as conforming to standard EN590). On average there is 5% of biofuel in regular diesel in the UK and can be up to 7% without needing specific labelling. Higher biofuel blend diesel typically refers to blends exceeding this 7% threshold. B20 and B30 denote higher biofuel concentrations up to the level labelled which aim to incorporate a larger proportion of low carbon biofuel to reduce the environmental impact of diesel. B100 indicates pure biodiesel with no fossil derived diesel.
In 2022, around 93% of the biodiesel supplied for use in the UK was produced from waste feedstocks and of this, 75% was produced from used cooking oil.
High-blend biodiesel is typically delivered to fleet depots with standard diesel storage and refuelling equipment. Most vehicle manufacturers warranty their Euro VI vehicles for blends of B20 and B30, provided the fuel meets the EN16709 standard, but fleet operators should check with their specific manufacturer(s). Insurers typically only insure for fuel up to B30.
Some manufacturers also warranty B100 if the fuel meets standard EN14214. If fleet operators wish to run on B100, biofuel suppliers can fit upgrade packages to certain engine types.
| Pros | Cons |
|---|---|
| B20 biofuel can achieve around 18% GHG savings, whilst B100 biofuel can achieve 85% GHG savings on a well to wheel (WTW) basis compared with regular diesel. Note Tailpipe “tank to wheel” (TTW) GHG emissions are considered zero so GHG emissions for B100 are released in the “Well to Tank” (WTT) upstream supply chain part of the full fuel cycle. | Depending on the manufacturer, vehicles may not be suitable for running on higher blends of biofuel without additional parts or retrofitting. Operators may need to purchase independent warranty to cover their HGV engine and parts when running higher blends of biofuel. |
| Made from existing waste products such as used cooking oil and food waste, which delivers higher carbon savings. This will have a lower impact on land use change and does not impact global food security. | High blend biodiesel is not available at retail fuel stations meaning HDVs running on this fuel type will need to consider lack of top up fuelling on their route plans or will need to consider running different blends in parallel. |
| Converting an existing vehicle to B100 use typically costs between £6500 and £8000 per vehicle (Source: Zemo Partnership Renewable Fuels Guide) or around £2000 per vehicle for B20 or B30. Whilst still an additional cost, it is significantly cheaper than other low or zero emissions options as it utilises the existing fleet. | Operators may need to adapt their depot refuelling infrastructure which will come at additional cost. |
| By-products from the production of biodiesel can be upgraded and converted into value- added end products such as glycerine. | Biodiesel of all blends can be affected by the temperature as it begins to gel (or waxing) if cooled down to between 0 and 10°C. Based on the average winter temperatures in the UK, this can present a problem for higher blends such as B100, so additional infrastructure is required such as heated tanks, lines and dispensing pumps. From an emissions perspective, unless produced using renewable sources, the energy required to maintain this temperature will be an additional factor. |
| Similar operating costs to standard diesel and a relatively simple transition for existing fleets in comparison to other zero emission options | Additional maintenance costs for B30 fuels are estimated at between £1000 and £2000 per year. |
Hydrotreated Vegetable Oil (HVO)
Hydrotreated (or Hydrogenated) Vegetable Oil (HVO) is chemically similar to conventional fossil fuel diesel, which means it can be substituted for diesel as a “drop-in” fuel as pure HVO and blended with fossil diesel at much higher rates than FAME. HVO can be produced from virgin vegetable oil or waste feedstocks such as used cooking oil and waste vegetable oils.
HVO must conform with European Standard EN15940. All UK supplies of HVO are currently imported from other parts of Europe and, if approved by the Renewable Fuel Assurance Scheme, come from sustainable, waste-based feedstocks. A few companies are now beginning to supply blends of low-carbon diesel, such as HVO blended with fossil diesel.
| Pros | Cons |
|---|---|
| Can be used without modification to fuel storage or engines. It is advised that operators check with manufacturers in the case of older pre-Euro V HGVs. | Not currently available at all retail fuel stations which presents additional challenges to route planning. HVO suppliers may need to provide and install refuelling infrastructure at depots in particular if to be used at higher levels. |
| If produced from sustainable and local feedstocks, it is generally accepted that HVO can reduce GHG emissions by up to 91%. | Cost of fuel per litre is 15 - 30% higher than diesel. |
| Maintenance costs for the vehicles are the same as regular diesel vehicles. | HVO availability whilst growing is limited and there is a risk of negative impact on the environment through land use change if produced from dedicated oil crops which are also used for cooking oil/fats. This could result in deforestation or impacting existing food supply chains. This can reduce the potential GHG reductions. |
| May provide benefits to performance of Euro VI exhaust after treatment systems. This is due to a reduction in the number of DPF regens and a lower AdBlue consumption (although this needs to be further evidenced with testing). | The UK doesn’t currently have any domestic HVO production therefore it requires importing from Europe, Asia and the US. This presents a risk around supply chains and the security of supply. There is also demands for HVO from multiple sectors, but also as HEFA in aviation which may create a demand that doesn’t match the supply, which consequently could limit the availability to the road sector. However, it is expected that this will change in the coming years using techniques such as fractionalisation and the pyrolysis of agricultural and forest wastes. Also, used cooking oil is a finite resource meaning there are concerns about the long-term sustainability of HVO as a fuel. |
| HVO can be stored in the same way and has the same storage life as regular diesel. | The fuel is produced through hydrotreatment of vegetable oils and the level of GHG reduction depends on the production process and hydrogen used (as there is no current distinction between renewable Hydrogen and Hydrogen produced from fossil fuel sources). |
| Most truck manufacturers approve and warranty HVO use as long as the fuel conforms to EN15940. | There are concerns that processes need to be in place to ensure that feedstocks currently classed as waste products are genuinely waste. |
| Robust verification of the source of HVO fuels is required as the reduction in GHG is dependent on the supply chain. An operator wishing to use HVO would need processes in place to verify feedstocks and production processes in order to see the projected reduction in GHG. |
Biomethane
Biomethane is the renewable equivalent of natural gas. It can be used as a drop in alternative for both CNG and LNG vehicles, but cannot be used in an unmodified vehicle.
When used as renewable vehicle fuel in the UK, biomethane is made from a variety of organic waste materials such as food waste, manure and agricultural residues via the process of anaerobic digestion. Currently over 70% of biomethane is imported from the EU and it can then be injected into the national gas network for distribution around the country (mixed with fossil natural gas). The gas can also be dispatched to a refuelling station and dispensed as compressed biomethane gas (CBG) or liquid biomethane (LBM).
| Pros | Cons |
|---|---|
| Not compatible with an existing diesel engine, meaning fleets would need to change over to running on gas. | |
| GHG emissions savings range are over 80% if dispensed as compressed biomethane gas (CBG), or over 69% if it is dispensed as liquid biomethane (LBM). If produced entirely from wet manure, this could be higher. | Gas HGVs can cost around 25% more than their diesel equivalent, although some companies offer vehicles on a lease. Similarly, gas vehicles are around 20-25% more expensive to maintain. |
| Biomethane is cheaper than diesel on a pence per mile basis fuel duty is 50% lower than standard diesel (Note: this rebate is time limited so potentially there is a risk of removal). | Additional up-front costs for installing depot refuelling stations and costs can vary depending on the level of pressure in the network at the connection point and the distance to the main gas network (although these can be recovered through lower fuel operating costs). |
| Compressed biomethane gas can be delivered through the national grid, which would cut GHG costs in the supply chain. | Currently produced on a small scale in the UK but likely to expand in the near future. |
| Gas heavy duty vehicles can run interchangeably on natural gas and pure biomethane with no impact on fuel consumption or warranty considerations. | Minimal public refuelling sites at present (as of January 2023, there are 10 public CBG stations and 10 CNG). There are plans to increase capacity of both types of fuel in the next 3 years. |
Other renewable fuels
There are various other forms of renewable fuel/energy potentially of relevance to freight operators:
- Biopropane – can be substituted for fossil LPG, such as used by some forklift trucks, with no impact on operational requirements. Produced as a co-product of HVO, greenhouse gas savings are typically 63-95%.
- Renewable (“Green”) Hydrogen –can be made by electrolysing water using renewable electricity and, in this form, is known as “Green” Hydrogen and can deliver overall GHG savings of almost 100%.
- Renewable electricity – For Battery Electric Vehicles (BEV) from sources including wind, wave, marine, hydro, biomass and solar. Renewable electricity will deliver almost 100% overall GHG savings and can come either from an operator’s own on-site systems (such as rooftop solar PV) or via a 100% renewable electricity tariff from your electricity provider.
Supply chain assurance
Whilst biofuel tailpipe CO2 emissions are accepted as zero, a vehicle may still release small quantities of other greenhouse gases such as methane (CH4) and nitrous oxide (N2O) which are potent greenhouses gases. If reporting as CO2equivalent then there will be small quantities of GHG emissions at the tailpipe.
The amount of CO2 produced during the growing and production processes can vary depending on a number of factors, which means assurance in the supply chain is vital. For example, growing crops to produce biofuels would have significantly less benefit if they are grown in areas where high carbon value vegetation (such as tropical forests or peat land) has been removed or where the land use change to grow biofuel crops causes a loss of biodiversity. As the UK relies on imports of biofuels with their associated feedstocks there is more exposure to this risk.
Renewable fuel suppliers claiming to use wastes are required to demonstrate that their feedstocks originate from genuine biomass wastes and residues, which means that purchasers of the biofuel can be assured that the fuel meets the criteria of being a low carbon fuel.
Supply chain verification
Suppliers of renewable fuels are required to provide their customers with a Renewable Fuel Declaration for batches of renewable fuel, or blends of renewable fuel, sold. This document identifies the life cycle GHG emission savings and intensity, the types of biomass feedstocks used to produce the renewable fuel, as well as confirmation of voluntary sustainability scheme certification. It also links to the requirements under the Renewable Transport Fuel Obligation Order (RTFO).
Each Declaration has a unique ID and identifies the customer as a Renewable Fuel Assurance Scheme approved fuel supplier.
Zemo Partnership’s Renewable Fuel Assurance Scheme aims to provide HGV operators with assurance of claims made by fuel suppliers of the GHG emission and feedstock sustainability performance of their renewable fuel products. The Scheme covers biofuel and renewable hydrogen supply chains. With increasing scrutiny of the product supply chains, the Scheme enables company procurement and fleet management teams to have confidence in the sustainability credentials of low carbon fuels.
Additional resources
Further information and case studies on renewable transport fuels is available from the following sources:
- Zemo Renewable Fuels Guide
- Renewable Transport Fuel Association (RTFA)
- Department for Transport – Low Carbon Fuels
Information on renewable hydrogen suppliers is available from Zemo’s Renewable Fuel Assurance Scheme. The Renewable Energy Guarantees of Origin (REGO) scheme provides transparency to consumers about the proportion of electricity that suppliers source from renewable generation.