Norwegian company Nasta AS is a family-owned company established in 1929. Based in Larvik, around 100 kilometers southwest of Oslo, Nasta is today the sole supplier of Hitachi construction machinery in Norway. It is for this machinery that the company converts diesel-driven engines to electric power.
Reducing CO₂ emissions in the construction industry
“The overall project started as a consequence of the government’s commitment to the Paris agreement,” explains Sjur Wethal, senior advisor, climate and customer solutions, at Nasta, “which requires a reduction in CO2 emissions of 55% by 2030. Of course, our industry is a big part of these emissions, so we started building zero emission machines.”
The first steps towards electrification of diesel motors occurred in 2019 when Nasta won the contract to provide emissions-free construction machines for a roadbuilding project in Oslo. “It was a pilot project, the world’s first zero-emissions building project,” says Wethal, “and we had a lot to learn about electrification. ABB helped us with powertrain components and their know-how.”
“The world’s first zero-emissions building project.”
The conversion procedure includes removing the existing fuel tank and diesel engine, and fitting an electric motor and drive, together with an energy management system, battery and charging solution, as well as a power connection. ABB supplies the electric powertrain components and provides technical advice. The equipment has to be able to withstand dust, moisture, heavy vibrations, and other aspects of harsh operating environments. “For the user of the machine, the operation will feel basically the same, but with some improvements,” Wethal comments.
Multiple benefits through electrification
“The main improvements are threefold,” he continues, “and the obvious one is of course the environmental effects. These machines have no carbon dioxide or sulphur dioxide emissions.” A diesel-driven 24-tonne excavator typically uses about 18,000 litres of fuel per year, which produces an annual total of around 48 tonnes of carbon dioxide emissions. These emissions are eliminated after the conversion.
Furthermore, the fact is that diesel and petrol engines are in general very inefficient, reaching efficiencies of 45% and 33% respectively. Electric motors, on the other hand, typically reach 95% efficiency. This doubling of efficiency from diesel to electric motors is a huge boon both in terms of costs savings and sustainability. The effect is particularly noticeable in the heavy machinery market, as nearly 46% of all emissions produced by diesel-powered construction vehicles are produced by those weighing more than ten tonnes.
“The second part is noise pollution. An electric motor runs much more smoothly than a diesel motor, producing less than half of the noise.” Naturally, this noise reduction improves the environment for both workers on the construction site and for people who live or work nearby. Anecdotal evidence from operators of the electrically driven machines suggests that the equipment is much more comfortable to use, also having reduced vibration.
“The main improvements are threefold.”
Thirdly, the longevity of the machinery is significantly increased. “A diesel-driven machine will have a life expectancy of 11,000-15,000 hours,” Wethal clarifies, “while the electric motor from ABB can have a pro-longed life of up to 50,000 hours, which means that now we can concentrate on the circular economy. We can change parts on these machines and still make them run for more years than a diesel-driven machine.”
A streamlined electrification process
Following the continued success of the conversion process, Nasta’s experience in the field of heavy electric machinery means that it is often called on to advise about policies and regulations for zero-emission construction sites. The Nasta team has undertaken around ten electrification projects, and resulting in a streamlined process and time savings, in addition to the aforementioned environmental benefits.
Overall, the success of this project is down to the expertise of Nasta’s personnel allied with the in-depth experience of suppliers including ABB. Electrifying diesel motors in heavy machinery makes construction easier, more sustainable, and more energy efficient.