When it comes to mobility, many organisations have high ambitions to make use of more electric vehicles and zero emission engines. An example of this is the engineering agency Royal HaskoningDHV that aims to transform their lease fleet to 100 percent electric by 2021. But what happens to mobile tools and equipment used in construction sites? What are the challenges and opportunities for electrification in the construction site of the future?
According to Frederik Oudman, consultant Environmental Quality at Royal HaskoningDHV, it is inevitable for the transition towards electrification to expand to other business sectors. The infrastructure and construction sector offers many opportunities for the use of electrically powered machinery during the construction process. Electric tools are cost effective, more efficient and has less impact on the environment compared to construction tools powered by fossil fuels, according to a report conducted by the research agency SGS Search. Another report by the Dutch government institution Rijksoverheid shows that the replacement of all (non-agriculture) mobile machinery can potentially lead to a CO2 reduction of 1,9 Mton and a reduction of 11 Kton nitric oxide.
Despite the numbers and initiatives to stimulate the use of electric tools, organisations in the infrastructure and construction sector seem to be hesitant about a large scale implementation of electric machinery. In this article, SKAO focuses on the challenges and opportunities of electrification in the infrastructure and construction sector.
About 80 percent of the total revenues in the Dutch infrastructure and construction sector is made possible by public procurement. These public and local authorities have committed to climate goals and major CO2 reduction, which they aim to achieve by acting upon sustainable public procurement and purchasing policies. For this endeavor, public authorities make use of the CO2 Performance Ladder, among other things. Based on research by the Foundation for Climate Friendly Procurement and Business (SKAO), there are more than 75 commissioning parties in the Netherlands that make use of the Ladder as an award criterion in tenders. This shows that public and local authorities are prioritizing sustainability and CO2 reduction in their projects.
The use of mobile tools in these construction projects lead to a considerable amount of carbon emissions. The use of electric tools therefore adheres to the sustainability goals of public authorities. Organisations that are certified on the CO2 Performance Ladder are stimulated to take measures that cut back their carbon emissions. An example of these measures taken to reduce CO2 is the replacement of machinery powered by fossil fuel to tools with electric engines. With a certificate on the CO2 Performance Ladder, organisations are to maintain and update a List of Measures to keep track of the measures taken towards CO2 reduction. The List of Measures is an obligatory part of the CO2 Performance Ladder. A glimpse of the List of Measures shows that certified organisations are already making use of electric tools such as forklifts to reduce carbon emissions during projects and in the daily activities of the organization.
SGS Search has recently conducted a research on the development of electric implementations of mobile tools used in construction sites. Based on financial and environmental considerations, the research shows that electrical mobile tools in the construction sector are more advantageous compared to machinery powered by fossil fuels. Furthermore, the research shows that electrical mobile tools provided with a power cable to the electricity grid have 30 to 50 percent lower operating costs and 50 to 90 percent lower CO2 emissions than the tools powered by fossil fuels. The Total Cost of Ownership (TCO) of electric tools prove to be lower than the TCO of diesel powered equipment. Both hybrid machinery as well as equipment with a connection to the electricity grid can annually save up to (ten)thousands of euro’s.
The researchers have not only focused on full-electric tools, but also electrical hybrid machinery used in construction sites. Based on the results, the researchers conclude that hybrid systems also lead to significant fuel savings of 15 to 30 percent.
An example of using hybrid machinery in the construction site is shown by the Dutch organization K_Dekker. During the development of the Forum Zuid in Utrecht, the company made use of a hybrid excavator that was needed to build the underground system of a bicycle storage space. “The co2 footprint of K_Dekker is made up of 40 to 50 percent of material fuels, which are used to operate our machinery during construction. The other 40 percent is caused by fuels used for transport”, said Huub Groenenberg, manager of Quality, Labor and Environment at K_Dekker in an interview with SKAO. “A hybrid excavator saves energy by creating momentum to win back some of the energy being used. Based on our calculations, a hybrid excavator can save up to 30 percent of fuel compared to traditional machines. This is a great amount of fuel savings and a measure we take based on our commitment to the CO2 Performance Ladder.” K_Dekker has managed to obtain a certificate on level 5 of the CO2 Performance Ladder, which is the highest level. According to the manager, 32 percent of the total revenues realized by K_Dekker in 2016 is made possible by projects in which the CO2 Performance Ladder plays an important part.
K_Dekker also made use of a hybrid concrete mixer in the construction phase of the Forum Zuid, which is near the central station of Utrecht. “The hybrid concrete mixer contains both a diesel engine as well as an electric motor”, Groenenberg explained. “When the truck stops at the construction site, the diesel engine will be turned off and the mixer is then powered by the electric motor. This saves fuel consumption of the machine, which also leads to a reduction of carbon emissions. Once the truck starts again, the diesel engine will be turned on. This is an improvement compared to traditional concrete mixers that make use of diesel engines alone.”
The research by SGS Search concludes that the environmental impact of electric machinery is a few dozen percentages lower compared to equipment powered by diesel. According to the calculations of the researchers, the environmental impact of machinery with a power cable and machinery with a battery pack are 50 to 70 percent lower. By using green electricity the environmental impact will additionally be cut back by 15 to 20 percent. A lower impact on the environment that is caused by using electric machinery translates to a cut back in greenhouse gas emissions such as CO2, but also a reduction of air pollution. Furthermore, the electric engine is a lot quieter compared to fossil fuel powered engines, which means that local residents will experience less noise disturbance during infrastructure and construction projects.
The possibilities of electric tools in construction sites are increasing. The German organisation Wacker Neuson gives an example therein with the development of a production line that contains solely zero emission machinery, such as excavators, forklifts and wheel dumpers. “Our systematic expansion of the Wacker Neuson zero emission range is a logical step for us as we look to the future. For many years now, legal regulations governing emissions from construction equipment have been getting stricter. We are going one step further here and aim to offer at least one zero emission solution in each of our main product groups”, says Martin Lehner, CEO of Wacker Neuson Group, in a press release. “Before we launch a new zero emission product, we have to be sure that the machine offers value for money over its service life and is cost-effective to run. This includes ensuring that each battery can run for an average working day on a single charge.”
Organisations experience the long charging time of battery packs as one of the challenges in using electric tools, claims Oudman. According to the consultant of Royal HaskoningDHV the long charging time does not need to be a challenge when the logistics of the construction site is adapted to the necessity to charge battery packs. Contractors can for example make use of modular battery packs, Oudman writes. The battery packs can be exchanged between the electric tools that the contractor needs at that moment, which makes it possible for a charged battery pack to always be available. Another possibility is speed up the charging time of electric tools in construction sites is to make use of medium voltage connections, the consultant writes. This can however impose challenges, because medium voltage connections are not cheap and it is only available in limited numbers. The consultant adds that there are ways to make the medium voltage connections more cost efficient by for example using the Dutch railway network, because it is largely powered by medium voltage power cables.
Construction sites will further implement electric machinery in the future. Next to the use of electric tools, the digitalisation of the construction site will also play a major part in reducing the environmental impact of the construction sector. A great example of the digitalisation of the construction site is the autonomously operating tools. Large organisations in the construction sector are already developing innovations such as 3D-printing concrete, a robot mason and drones that make construction work more efficient. Oudman speaks of the construction site of the future.
The up and coming technological innovations that make construction sites more efficient and sustainable are confirmed by the Dutch bank ABN Amro. In a report, the bank concludes that the construction sector is in need of an industrial revolution to maintain its competitive advantage. ABN Amro further claims that technological innovations in the construction sector offer many possibilities to improve both products as well as processes of the construction sector. Moreover, the innovations in this industrial revolution has the potential to solve possible threats to the construction sector, such as shortage of personnel, environmental impacts, disturbances and unsafe working conditions.
The construction site will further electrify in the future. The electrification of mobile tools is an important part of this transformation and offers opportunities to save costs and to preserve the environment. Both the practical experiences as well as researches confirm the opportunities that electrification brings. At this moment, we are at the start of the transition to electric tools in construction sites, but already the possibilities are endless.