Notice

Red Diesel Replacement competition: Phase 2 projects

Updated 9 June 2026

Phase 2 of the Red Diesel Replacement (RDR) competition funded industry-led projects to develop and demonstrate end-to-end, low carbon alternatives to replace diesel across construction, mining or quarrying sites. Over £21.3m in grant funding was claimed across 6 projects, leveraging over £11.5m in private match funding.

These projects brought together a wide range of industrial organisations to integrate low-carbon technologies across the end-to-end chain to decarbonise off-road machinery on active sites. Through demonstrating and assessing real-world performance, cost and operational feasibility, the programme supported the technological advancement of these low carbon technologies and aimed to accelerate their commercial adoption in UK industry.

DEPOWER 2

• Project lead: Danfoss Scotland Limited
  
• Location: Edinburgh
  
• Grant amount: £4,287,148.98

Project description

A major barrier to electrification of construction equipment is cost associated with large, expensive batteries and suitable charging infrastructure due to the high power consumption of these machines. Currently, excavator hydraulic systems waste around 70% of useful power delivered by the engine. This project aimed to accelerate electrification of these machines through improving the energy efficiency of excavators, which reduces battery size and charging energy required.

Invented, developed and manufactured in the UK, Digital Displacement® is a fundamental advance in hydraulic power, replacing traditional analogue mechanisms with innovative digital pump and actuator control systems. The first two tiers of Danfoss’s Dextreme products, Swap and Flex, had been proven to reduce energy consumption by 15% and 30%, respectively. This project demonstrated the next iteration of the product, Dextreme Max, and aimed to reduce energy consumption by up to 50% of traditional excavators, through reducing energy losses and recovering waste energy.

Under Phase 1, a prototype Digital Displacement pump/ motor was developed to enable energy recovery, and proven to reach expected efficiency levels on a test rig. Phase 2 integrated this into a large battery/ electric excavator, and demonstrated operation in a quarry. The project also aimed to prove the components of the technology (machine, controller, system hardware and software) and developed simulation tools to accelerate development.

Final report: DEPOWER 2

Demonstration of decarbonised quarrying operations through E-Diesel and hydrogen dispensing technologies

• Project lead: CATAGEN Limited
  
• Location: Belfast
  
• Grant amount: £6,248,017.71

Project description

This Phase 2 project was delivered by a consortium of three NI-based successful RDR Phase 1 recipients; CATAGEN, TEREX and WRIGHTBUS. The project sought to build on the success of the consortium partners’ Phase 1 projects to produce a robust set of equipment, integrating conventional and novel technologies, for quarrying and recycling industries with net zero carbon emissions and a significant reduction in all engine emissions.

The objective was to develop the solution to pre-production readiness level and demonstrate refuelling at an active quarrying site. The benefits of this concept lie in the integration of well-proven equipment with new technology capable of delivering a fully decarbonised, robust solution for the industry.

The scope covered 3 main themes:

1. Evolution of the TEREX crusher and screener for improved energy efficiency through low-carbon power supply.

2. Development of CATAGEN’s e-diesel technology (ClimaHtech E-FUEL GEN) for pilot-scale production.

3. Demonstration of CATAGEN’s static compression technology (ClimaHtech COMPRESSOR) for high pressure hydrogen compression and integration of CATAGEN’s hybrid mobile compression and dispensing technology to support refuelling of a hydrogen genset and dual-fuel engine at a demonstration site.

The project modelled alternative fuels for on-road and off-highway applications, planned future use and developments post-demonstration for commercialisation of the technology. Key learnings and results were shared through dissemination activities.

Red garnet red diesel generator alternative

• Project lead: H-Power plc (formerly AFC Energy plc)
  
• Location: Surrey
  
• Grant amount: £2,518,516.68

Project description

AFC Energy formed a well-to-work consortium to demonstrate the use of green hydrogen to displace diesel at UK quarry sites. AFC Energy developed modular, scalable hydrogen fuel cell and hydrogen-carrier conversion systems, working with; Energy Solutions, a battery energy storage system (BESS) manufacturer; and Brett Aggregates, a quarry operator and cement supplier.

The project demonstrated the supply chain and technology of AFC Energy’s H-Power S/S+ Series emissions-free hydrogen gensets through one month deployments of green hydrogen-fuelled gensets at two quarry locations. The gensets displaced red diesel generators across the two most deployed power ratings: 30-50kVA and 250kVA. The H-Power S Series is an air-cooled fuel cell generator which was operated with a BESS with a minimum usable capacity of 45kWh and the H-Power S+ Series is a liquid-cooled fuel cell generator operated with a BESS with a minimum usable capacity of 184kWh.

The gensets’ deployment demonstrated the flexibility and power range of hydrogen fuel cells, BESS and the potential to displace virtually all off-grid diesel generators in construction, mining and quarrying sectors. Demonstration in working quarry sites under identical conditions enabled the cost of ownership, durability and suitability of the emissions-free gensets to be established. Key findings from the project were shared through dissemination activities.

Final report: Red garnet red diesel generator alternative

Comprehensive hydrogen supply-chain solutions for NRMM (H2-to-Site)

• Project lead: Ryze Hydrogen Limited
  
• Location: Oxford
  
• Grant amount: £2,360,602.37

Project description

The H2-to-Site project successfully demonstrated a flexible, end-to-end hydrogen supply chain solution for non-road mobile machinery (NRMM), operating in real construction environments. The project addressed one of the key barriers to hydrogen adoption in construction: the lack of practical, mobile refuelling infrastructure suitable for temporary and evolving site conditions. 

Working alongside partners including Wrightbus, iGAS Technology Solutions, Skanska, Mace Dragados and Sizewell C, the project developed and validated a suite of modular hydrogen technologies including Mobile Refuellers (bowsers), tube trailers, mobile compression systems, and bespoke transportation and handling equipment. 

Testing progressed from controlled quarry demonstrations to live operational deployments across multiple construction sites. Over the programme, more than 3,000 road miles were completed by hydrogen logistics assets, delivering hydrogen to a range of working sites: including housebuilding construction sites, wastewater treatment plants, and storage yards. Hydrogen-fuelled construction equipment including generators, telescopic handlers and backhoe loaders were successfully refuelled under real operating conditions. 

The project demonstrated the operational feasibility of mobile hydrogen supply chains for construction, while supporting the development of operational procedures, safety methodologies, and deployment learnings to help inform future hydrogen adoption across the UK construction sector.

Element1: Leading the construction industry towards zero emissions future

• Project lead: BAM Nuttall Limited
  
• Location: Camberley
  
• Grant amount: £4,539,897

Project description

Element1 designed and demonstrated an end-to-end solution for the manufacture, supply, distribution, storage, and use of hydrogen as an alternative to diesel on a construction site, powering construction plant and equipment. The project aim was to accelerate displacement of diesel-fuelled technologies whilst enabling existing plant to continue in use over its remaining lifecycle.

The project adapted and developed dual fuel technology, converting a range of construction plant alongside a hydrogen fuelled generator. The project also developed a hydrogen supply chain, including off-site production and on-site, off-grid compression, as well as developing innovative on-site storage and distribution solutions, tailored to on-site construction requirements.

The project demonstrated on three construction sites for several months and addressed barriers to hydrogen production, supply and use including skills/ training needs, H&S and regulatory issues. The demonstration supported market assessment and business cases for investment and measured and assessed impacts on site productivity and emissions compared to conventional diesel plant with learnings disseminated to wider industry.

BAM and Skanska provided access to construction sites to demonstrate the solution, with GeoPura supplying hydrogen and a hydrogen powered generator with an off-grid hydrogen compressor, Reynolds Logistics addressed hydrogen transport/logistics, GeoPura adapted/developed storage and onsite distribution capabilities to suit the needs of site-based construction, ULEMCo developed a hydrogen bowser and adapted their dual fuel technology to convert plant provided by Flannery and Plantforce prior to demonstration and assessment, and BRE provided independent assessments and metrics.

Final report: Element1: Leading the construction industry towards zero emissions future

Hybrid gas engine 2 (HGE2)

• Project lead: Cage Technologies Limited
  
• Location: Lancaster
  
• Grant amount: £1,396,349.13

Project description

Hybrid gas engines (HGE) have a similar performance and efficiency to diesel engines. Their short-term deployment can: displace diesel in construction through the use of widely available, cost-effective gas fuels; support the transition to net zero fuels such as hydrogen; and introduce renewable DiMethyl Ether (rDME) as a new fuel blended with LPG. 

The HGE2 project built on the RDR Phase 1 HGE project, and developed 7 new working prototype gas engine platforms able to use hydrogen, LPG or other gas fuels which were installed in generators and demonstrated in trials on the HS2 rail construction project with partners EKFB, Speedy Hire, Calor gas and Imperial College London. The engine platform was also developed to accept rDME blended with LPG; rDME is a low-carbon, part-renewable fuel with similar properties to LPG in terms of storage and transportation.  

The project objectives were to show advantages and address barriers in the adoption of alternative gas fuel engines in the off-highway sector whilst ensuring that UK and EU emission standards were surpassed. The project validated the HGE technology to lay a pathway towards commercial supply at scale, whilst developing measures to ease safe supply of alternative gas fuels to the construction sector at the point of use.