The future of energy-efficient asphalt production – sustainable developments at SWIETELSKY Magyarország

In the previous part of our interview series previous part of our interview series, we spoke with the heads of the SWIETELSKY Magyarország water engineering, environmental protection and waste management departments. József Tomacsek, head of sustainability, also participated in the interview, but his presentation on sustainability developments related to asphalt production was so comprehensive that we decided to cover it as a separate topic.

József Tomacsek has been working at SWIETELSKY Magyarország for two decades, where, as chief technologist and energy engineer, he is responsible for the operation, development and energy optimisation of eight asphalt mixing plants, among other things. As he said, the company has been certified since 2015 with the ISO 50001 energy management system, in connection with which they are constantly examining opportunities for savings.

„Since we have had to purchase electricity and gas from the free market, we have been paying particular attention to rationalising consumption,” said József Tomacsek. „These are complex systems in terms of both energy and technology, as every small change in an asphalt mixer has an impact on the entire production process.”

The expert is actively involved not only within the group of companies, but also in the work of professional organisations: he is a member of several working committees, the Hungarian Asphalt Industry Association (HAPA) and Magyar Út- és Vasútügyi Társaság (MAÚT), where he works on the development of regulations and standards. In addition, he regularly holds internal training sessions on energy and sustainability topics for colleagues in the infrastructure sector.

The efficiency of asphalt mixers is a key issue

One of the greatest advances of the SWIETELSKY Magyarország Kft. in recent years has been the increase in the energy efficiency of asphalt mixers. The aim of the developments is to produce asphalt mixes with the least possible energy consumption during the manufacturing process, while maintaining the usual quality.

„One of the most important areas is the modernisation of asphalt mixers. For example, we examined how we could reduce the energy consumption of high-performance extraction fans: previously, these operated at a fixed, full capacity, but now, with the help of frequency converters, we can adjust the output to the actual demand. This means they consume up to 60–70 per cent less energy.”

said the chief engineer.

The company constantly monitors areas where further savings can be achieved. During energy audits, thermal imaging cameras are used to analyse heat loss from drying drums, hot elevators and bitumen tanks. „The use of more modern insulation materials and stationary, electrically heated tanks for this equipment results in significant energy savings,” emphasised the expert.

Moderately warm technology and reclaimed asphalt

One of the most effective ways to reduce CO₂ emissions in asphalt production is to use a moderately warm technology known as WMA (Warm Mix Asphalt). This method allows for lower-temperature production, requiring less energy for heating while also improving the working environment.

„Our three plants – in Székesfehérvár, Szarvas and Dunakeszi – are already capable of producing moderately warm asphalt, i.e. working with foamed bitumen,” says the expert. „We currently use this technology primarily for transportability and safe installation, but if domestic regulations become stricter, we could immediately introduce temperature reduction.”

The recycling of reclaimed asphalt is also an important step towards circular construction practices. All SWIETELSKY mixing plants have a reclaiming option, which allows part of the milled asphalt to be incorporated into the new mix. „We are technically ready for higher refeeding rates, but current regulations still limit its use in SMA wearing courses, for example,” he added.

Covered storage facilities and solar panels – a double advantage

In recent years, the company has built covered depots at several of its sites, which serve both technological and energy efficiency purposes. This prevents the stored stone materials from getting wet and absorbing water, which means that less energy is required for drying during asphalt production.

„In covered storage facilities, fine-grained rocks do not become damp, so less energy is needed to evaporate moisture. This is a typical example of how technology and energy are interrelated,” explained József Tomacsek.

The roofs of the depots are also utilised with SWIETELSKY solar panels: a 50 kW system is already in operation at four sites – Dunakeszi, Szarvas, Múcsony and Vasvár – which generates electricity on a monthly balance. „When it became clear that net metering would be discontinued, we quickly submitted requests for all our sites and, where network conditions allowed, we implemented them. A new solar panel system is now being built in Görbeháza, which can be expanded with energy storage in the future,” said the chief technologist.

Innovative materials and a new approach

Sustainability is reflected not only in energy consumption, but also in the materials used. In its experimental projects, SWIETELSKY Magyarország is also testing new materials such as glass asphalt, which uses waste glass granules as an additive. In addition, several projects have used a fibre reinforcement material called Forta-FI, which increases the load-bearing capacity of asphalt.

„This fibre material is like adding iron to asphalt – only half a kilogram is needed per tonne, yet it significantly increases the strength and durability of the mixture. This means that we can build a pavement with the same load-bearing capacity even at a lower thickness, which also saves materials and energy in the long term.”

- he said.

According to the expert, domestic regulations do not yet sufficiently encourage this type of green solution. „In Norway and the Netherlands, for example, green construction methods are rewarded with extra points in the evaluation of tenders, and in certain urban zones, only electric machines are allowed to operate. We can see the direction of development, but we are still at the beginning of the road.”

Continuous examination, continuous development

At SWIETELSKY, energy efficiency is not a one-off project, but an ongoing approach. The company uses LED lighting, sub-metering systems and detailed energy monitoring at all its sites to see exactly which units are operating less efficiently.

„Based on the data from the sub-meters, we can even compare the energy consumption of individual machines between sites. If there is a discrepancy somewhere, we know immediately where to take action.”

– says József Tomacsek.

The company also aligns its energy efficiency investments with government programmes: for example, it plans to install energy storage systems in the future as part of the Jedlik Ányos programme. The return on investment of developments is always analysed in detail before a decision is made.

Committed to future generations

The activities of SWIETELSKY Magyarország Kft. extend beyond current projects: the company takes a long-term view in its sustainability reports and developments. As József Tomacsek puts it:

„Our goal is to ensure that future generations can also enjoy the infrastructure we are building today. That is why we are working to minimise the environmental impact of every step of asphalt production, from raw material procurement to manufacturing and recycling.”

According to the expert, sustainability in practice is not a single spectacular innovation, but a combination of many small, conscious improvements. „If we make small improvements at every site, on every machine, and in every technological detail, the cumulative effect will make a huge difference. This is our path to a greener future.”

The SWIETELSKY Magyarország Kft. has made energy efficiency and environmentally conscious technological developments an integral part of its corporate strategy. Continuous modernisation, the installation of solar panel systems, moderate-temperature technology and the reuse of recovered asphalt all serve to keep the company at the forefront of sustainable construction – not just today, but for decades to come.