As the Zero Diesel sites road map is released, CN asks if it will be a rocky road ahead
The construction sector is seeking operational dividends by introducing a green plant on site to align with the government’s net zero commitment by 2050.
However, implementing the change is complicated by the variety and complexity of machinery used on site, as well as the industry’s deep-rooted use of diesel.
The government-backed Zero Diesel Sites Roadmap report, launched at the HS2 Old Oak common station site on June 5, estimates that 300,000 items of construction machinery are in use today, consuming around 2, 5 million tons of diesel per year. Along with this, 2.07 million tonnes of diesel fuel are used to transport construction materials to and from the sites.
The CO2nstructZero campaign report describes how a working group of 30 construction companies and industry organisations, including leading contractors such as Kier, Laing O’Rourke and Morgan Sindall, is contributing to a shift towards zero emissions work, with the aim of reducing the use of diesel on site by 78% by 2035.
Some contractors have made progress in rolling out diesel-free operations, such as a Mace project at 78 St James’s Street in London’s West End and Skanska’s HS2 site at Kilburn.
And new greener machinery includes a hydrogen-powered backhoe for the construction industry, launched by JCB in February 2023.
To build on progress to date, the roadmap aims to encourage a more systematic approach by setting deliverable milestones and raising awareness of the range of solutions that can reduce the industry’s carbon footprint.
Speeding up the shift
The roadmap says the initial priority “is to accelerate the shift of the construction workforce to zero-emission vehicles and on-site plant.”
This change takes many forms in the roadmap, from improved telematics and anti-idling technology, with industry consultation and guidance published by the end of 2023, to diesel-free operator training.
The CO2nstructZero report notes that the adoption of biofuels alone is insufficient to meet the 2035 target. It adds: “Broader action is needed to achieve decarbonisation of the entire construction sector in the medium to long term.”
It underlines the need to adopt sustainably produced hydrogen, ideally generated through electrolysis (or ‘green hydrogen’ production).
“The use of hydrogen combustion and fuel cell generators could reduce emissions and noise, creating benefits for the community,” the report states. “Additional benefits include the ability to modernize existing ones [machinery] to make it hydrogen-enabled, in addition to the opportunity to share [hydrogen] infrastructure with other local end users”.
No incentives
However, the report avoids recommending a specific type of technology or identifying “a ‘silver bullet’ approach or technology that will fully address the industry’s current diesel use.”
Delivering zero diesel would inevitably cost money for an industry already struggling with thin profit margins and a tough business climate. Industry and Economic Security Minister Nusrat Ghani (whose portfolio includes construction) attended the launch. He said there was “no time to waste” in delivering zero diesel, but a government spokesman said Construction news that no incentives will be offered to help the industry meet its 2035 target.
Matt Palmer, Industry Sponsor of the Construction Leadership Council for Net Zero and Chief Executive of Lower Thames Crossing at National Highways, said: “The key [about the route map] is that it gives a clear direction of travel. This plan puts in place support for hydrogen, electricity and [generation of] other sources of clean energy. It also helps outline what businesses need to do in their own journeys and, crucially, get customers to try to drive commitments to ban diesel.”
He added: “I’m desperate for a plan, and this is the start of a very good plan to decarbonise our building. We need to stop talking about what we’re going to do and get on with it, and the best of HS2 is already a leader in this field.”
The journey to no diesel
HS2 Ltd aims to eliminate diesel from all its sites by 2029, HS2’s head of environmental services and co-chair of the Zero Diesel Working Group, Andrea Davidson, said. CN that the Old Oak Common site “is on the road to diesel”.
Six cranes at Old Oak Common run on grid power, and machinery such as excavators run on hybrid fuel, Davidson said, adding that 250 kVA GeoPura hydrogen fuel cell generators have been installed at the site. It is also the first site to host all-electric crawler cranes that can run on battery or mains power.
The flywheel’s energy storage technology is being trialled elsewhere on HS2, and Davidson said installing energy storage systems in tower cranes “is a very smart efficiency technology ” to avoid overvoltages.
Elsewhere in the construction industry, Aggreko says its ongoing partnership with Zero Diesel Task Force member Sir Robert McAlpine produced an 85% reduction in emissions and fuel at an unnamed site between October 2022 and January 2023.
The test of five tower cranes included battery energy storage systems and small generators powered by hydrotreated vegetable oil (HVO). Aggreko estimates that it reduced emissions by 234 tonnes and reduced fuel consumption by more than 87,300 litres.
Phased approach
So far so good, but Davidson pointed out one problem area that the road map aims to address. There are already solutions for light equipment and heavy plants such as cranes, but “it’s the middle band we’re going to be dealing with,” Davidson said, such as 20-ton excavators.
“That’s where we’re looking at biofuels as a first step with the exit fuel,” he said. “The next step is to figure out where dual hydrogen fuel systems fit into the mix.”
There is no obvious technical reason why the gap exists for the medium-weight plant, an HS2 spokesman noted, adding that the solutions “either don’t seem to be in the market or they don’t make it into our chain of supply in the same volume as [solutions for] light or heavy weight kit”.
According to Palmer, construction’s biggest barrier to reducing diesel use is the perception of higher cost and risk. “In my experience, the reality is that both of those are reduced as we start to move on [zero diesel] trip,” he added.
The roadmap document also highlights the need to improve safety training on alternative fuels and energy sources. This was echoed by the Electrical Contractors Association’s director of corporate social responsibility, Paul Reeve, who is leading the safety aspects of the zero diesel initiative.
Diesel alternatives “present emerging hazards” if stored or handled unsafely, he said CNadding: “As such, it’s about recognizing potentially high operational hazards and taking steps to ensure they continue to operate at low risk.”
