Energy: the invisible raw material in asphalt production

Why efficiency must become a business imperative, not a nice-to-have 

In 1959, the UK opened its first major motorway, the M1, with a 67-mile stretch. Including connecting feeder roads, the new route spanned around 72 miles and relied on thousands of tonnes of asphalt — a mixture of aggregates and bitumen that continues to be fundamental to roadbuilding today. Modern asphalt plants are complex facilities that rely on heavy-duty machinery to mix, dry and transport materials at scale, but beyond stone and binder, every tonne of asphalt requires vast amounts of energy. Here, David Strain, technical director at integrated automation system expert, Technidrive, explains why energy must be reframed as the industry’s invisible raw material, and why efficiency is now a business imperative.

The overlooked raw material

Asphalt producers spend enormous time and attention sourcing aggregates and bitumen, but comparatively little time on optimising the energy used in the production process. In many asphalt plants, equipment such as dryers, exhaust fans, mixers and skip drives represent some of the highest electrical loads — yet their energy consumption is not always monitored as closely as other production inputs.

This is a blind spot. Energy is just as integral to the final product as stone or binder and the way it is managed can be the difference between profit and loss.

For too long, energy efficiency was considered a future ambition or an optional environmental badge. Today, rising energy costs and tightening net-zero requirements mean that ignoring it is no longer an option. Energy is the invisible raw material of asphalt production and must be managed with the same focus as any other input.

From optional to essential

The economics of asphalt production are under increasing pressure. Plants are energy-intensive by nature and when electricity costs surge, margins are quickly eroded. At the same time, industry-wide commitments to reduce carbon emissions mean producers are expected to demonstrate measurable progress toward sustainability.

In the United States, the National Asphalt Pavement Association (NAPA) has pledged to reach net zero by 2050 through its Road Forward initiative. In the UK, the Mineral Products Association (MPA) has published a Roadmap to Beyond Net Zero for the mineral products sector, underscoring the expectation that asphalt producers will take action on efficiency and emissions.

The best energy is the energy you don’t use

One of the most important principles in energy management is that the greatest saving comes from energy you never consume in the first place. Too often, asphalt plant equipment runs at full capacity regardless of the demand placed on it. Exhaust fans operate at maximum speed even when reduced airflow would suffice, mixers strain unnecessarily between loads and skip drives cycle inefficiently. Each of these practices results in wasted energy and unnecessary operating costs.

By implementing variable speed drives (VSDs), high-efficiency motors and smart control systems, plants can ensure equipment only works as hard as it needs to. Sensors provide real-time feedback to control systems, automatically adjusting motor speed or fan pressure to meet actual process requirements. Instead of blunt, all-or-nothing operation, energy use becomes finely tuned to production needs. This shift from uncontrolled consumption to demand-led operation is where the most transformative savings are achieved.

Making energy visible

A critical part of reframing energy as a raw material is making it visible. Operators and managers are used to thinking in terms of tonnes of asphalt produced, but less accustomed to measuring energy use per tonne. When consumption is monitored and reported in these terms, the impact of inefficiency becomes clear.

One way of monitoring is conducting energy assessments where monitoring equipment is installed to measure baseline consumption over the course of a specified period of time. By comparing energy use before and after system upgrades, producers can see exactly how much electricity, and therefore money, they are saving per tonne of asphalt. This transparency changes the conversation, turning efficiency from an abstract concept into a tangible operational metric that directly affects the bottom line.

While cost reduction is the most obvious benefit, efficiency also improves reliability and safety. When equipment runs only as hard as required, mechanical stress is reduced, extending the lifespan of motors, gearboxes and drives. This results in fewer breakdowns, lower maintenance costs and less downtime. Smarter control also reduces the risk of operator error and equipment overload, contributing to a safer, more resilient working environment.

Real-world results

In a recent project, a leading quarry and asphalt manufacturer faced spiralling energy costs due to an exhaust fan system running continuously at full speed. By retrofitting a high-performance VSD and upgrading to an IE4-rated motor, the fan was brought under precise control.

The result was a 38 per cent reduction in energy use, saving more than €30,500 annually while also cutting carbon emissions by over 750 kilograms per year.

In another case, McQuillan Quarries faced chronic downtime caused by repeated failures in its asphalt mixer gearboxes. The solution required more than efficiency; it demanded reliability. Technidrive engineered a bespoke planetary gearbox system designed to withstand the shock loads of mixing bitumen and stone. The new design eliminated failures and has operated reliably for more than five years, delivering consistent output with drastically reduced maintenance requirements.

By addressing inefficiency and unreliability simultaneously, asphalt producers can achieve both financial and operational gains.

Reframing energy as material

No asphalt producer would tolerate the unnecessary loss of aggregates or bitumen. Yet plants often accept wasted energy as unavoidable, even when the scale of loss is comparable. The difference is that energy cannot be seen or stockpiled. Treating it as an invisible raw material corrects this blind spot, forcing managers to recognise it as a core component of production that must be optimised.

Furthermore, reframing energy efficiency as a business opportunity rather than a compliance obligation is essential for the industry. Smart monitoring and control, high-efficiency motors and bespoke engineering interventions do not just cut costs; they improve reliability, enhance safety and reduce emissions.

Asphalt producers must work closely with a system integrator to survey operations, design tailored solutions and integrate them seamlessly into existing plant controls. The outcome is an operation where energy use is transparent, controllable and efficient — a plant that consumes less, produces more reliably and competes more effectively.