Electrification and renewable fuel clearest pathway to zero-emissions construction

The substantial carbon footprint generated by construction activities can be mitigated with emissions-free technologies such as electrified equipment and more sustainable forms of fuel.

The construction sector accounts for more than a third of global carbon emissions, of which emissions from sourcing and producing materials, logistics, and other construction activities make up more than 16 per cent.

The need for electric solutions in the construction industry is being driven by increasingly stringent emissions regulations, as well as high fuel costs, which is seeing a move away from diesel engines to electric or hybrid equipment.

Along with producing zero emissions, electrified construction equipment also reduces noise pollution and improves air quality, which is important for construction sites located in urban areas.

Being more efficient than internal combustion engines, electric motors require less fuel and maintenance and thus have lower operating costs.

However, considerable infrastructure is needed to charge electric equipment on site – particularly for larger machinery – which can create financial barriers to adoption.

The cost of electrified equipment is also significantly higher than diesel-powered machinery.

A range of low and zero-emission technologies in non-road construction machinery was investigated by researchers at the University of Queensland (UQ) in partnership with Lendlease, which documented the different types and sources of emissions generated on construction sites, the practices to reduce those emissions, and the alternative fuel sources currently available.

The researchers estimated that 40 per cent of construction machinery and equipment – by energy use – could be replaced by electric by 2030, and potentially grow to 60 per cent by 2040.

They said: “This means there is no current pathway to zero emissions construction by 2040, unless we see deep acceleration in the provision of electric construction machinery and equipment.

“It is more probable that concerted efforts will see us achieve fossil fuel free construction by 2040 and full electrification and absolute zero emission by 2050.”

A crucial finding in the UQ research was that construction met its definition of a ‘hard-to-abate’ sector, or any sector which may not have a straightforward transition pathway due to prohibitive costs or lack of technology.

Industries typically considered hard-to-abate are those that produce heavy materials like steel, aluminium, and cement, while heavy-duty transport – which includes road trucking, aviation, and shipping – is also considered hard-to-abate.

While carbon-intensive activities can be found across the whole construction value chain, the main source of hard-to-abate emissions in the building stage come from trucks, diggers, cranes, equipment, and the diesel used to power them.

However, the types of zero-emission technology to fully decarbonise construction sites is not extensively available, and unlikely to be so until after 2040.

The study determined getting to full electrification required a multi-pronged approach, with plug-in and mobile electric equipment powered by renewable diesel presenting the clearest pathway to fossil fuel-free construction.

Renewable diesel is an advanced biofuel made from animal fats, vegetable oils, and agricultural waste – due to being chemically identical to conventional diesel, the renewable variety can be used as complete substitute without machinery needing modification.

UQ’s research confirmed low-carbon fuel policies, financial support mechanisms and carbon reduction targets in Europe and the US had been key drivers of growth in local renewable diesel industries.

It also highlighted electricity grid constraints as a major long-term obstacle to the electrification of construction; specific constraints include a lack of capacity and ability to manage peak load.

If construction machinery is unable to ‘plug in’, continued work then becomes dependent on diesel generators to cover the energy discrepancy.

Until two renewable diesel refineries in Queensland and Western Australia begin production in 2025, the fuel will not be commercially available in Australia.

However, biodiesel is a suitable alternative, which while far from zero emissions, is much less polluting than conventional diesel.

By Berkay Erkan