Efficiency is the new fuel: Rethinking motors for a sustainable future

Piyush Verma, Co-Founder at Naxatra Labs, writes about the relevance of and the science behind application-specific motor design.

Motors have become a ubiquitous part of our modern life, silently existing in almost everything that makes motion possible. However, on the flip side, they also consume over 50% of the global electricity generated. While motors enable our lives and industries, most of them still rely on decades-old designs that are inefficient by today’s standards. As nations commit to reducing carbon emissions and embracing sustainable energy, there’s one truth we cannot ignore: motor efficiency is energy efficiency. Every percentage improvement in motor efficiency translates directly into massive electricity savings and reduced emissions.

Therefore, a significant part of efforts towards carbon neutrality should also focus on making these motors increasingly efficient. We believe the future of clean energy demands not just more motors, but better, application-specific motors.

Historically, motors were built on a generic design philosophy, a single motor type repurposed across applications. While convenient for mass production, this approach led to two inefficiencies:

• Over-engineering: Motors that are heavier, bulkier, and consume more energy than required.

• Under-performance: Motors that fail prematurely due to overheating, poor load matching, external factors or unsuitable duty cycles.

For example, if an induction motor designed for industrial pumps is repurposed in an EV, it would struggle with torque density, heat management, and regenerative braking integration. Each application brings unique technical demands. Designing motors for these specific needs unlocks higher efficiency, reliability, and sustainability.

Let’s take a look at a few applications and how they differ:

Electric Two-Wheelers

• Key Needs: High torque density for stop-go traffic, high efficiency over drive cycle, thermal stability in hot climates, and regenerative braking compatibility.

Drones/UAVs

• Key Needs: Ultra-lightweight construction, high RPM (10,000+), weatherproof, rapid dynamic response, and low inertia.

Agricultural Machinery

• Key Needs: Ruggedness, high starting torque, and ingress protection (IP67+). Must withstand dust, water, and mud.

Power Tools

• Key Needs: Compactness, shock resistance, and intermittent high-load duty.

Industrial Machines

• Key Needs: Long continuous operation, reliability, compliance with IE4/IE5 efficiency classes.

Robotics

• Key Needs: High Precision position control, high torque, zero backlash.

Motor Efficiency is the New Fuel

When the world discusses clean energy, we imagine solar panels, wind farms, and EV batteries. But there’s a quieter, hidden revolution: motor efficiency.

• IE Standards: Motors are classified under IEC efficiency classes — IE3 (Premium), IE4 (Super Premium), IE5 (Ultra Premium). Moving industries from IE2 to IE4/IE5 can save hundreds of terawatt-hours annually.

• Induction vs PMSM: Induction Motors: ~85–88% efficiency | PMSM: ~94–96% efficiency with better torque control.

• Impact Example: A 2 kW EV motor, improved from 88% to 94% efficiency, saves ~100 kWh annually per vehicle. Multiply this by 1 million EV 2W sold annually – the savings equal several gigawatt-hours of power plant output.

In short, every percentage point in efficiency is equivalent to new power generation capacity.

The Science Behind Application-Specific Motor Design

A motor is essentially an energy converter. Its performance depends on how efficiently it moves energy:

• Electrical → Magnetic: minimizing copper loss through slot fill optimization and low-loss laminations.

• Magnetic → Mechanical: shaping the torque curve so that the motor delivers peak efficiency at the exact speed band of the application.

• Mechanical → Thermal: channeling heat away through materials, coatings, and housings effectively.

For example, in an EV scooter motor, we optimize the efficiency band around 35–50 km/h, because that’s where the vehicle spends most of its life in the city. In agricultural motors, we flatten the torque curve at lower RPMs to handle pump loads without overheating.

1. Electromagnetic Architecture

At the heart of every motor lies its electromagnetic design, the geometry of stator slots, winding patterns, and magnet configuration. Instead of using fixed templates, we tune the architecture to the load profile of the application:

• Concentrated windings for applications where torque transients dominate.

• Distributed windings for applications where smooth torque and NVH (Noise, Vibration, Harshness) are critical.

• Halbach magnet arrays in drone motors for higher air-gap flux without adding mass.

Detailed simulation of flux density maps, cogging torque profiles, and harmonic distortion allows to ensure the chosen design aligns with the intended duty cycle.

2. Thermal management

Heat is the number one motor killer. The motor design has to be optimized considering the external conditions the motor is to be deployed in.

For e.g. an EV in India during summers can see an ambient temperature of upwards of 50°C, for which the motors need to sustain and function effectively,

• Optimized slot fill factors to minimize copper loss.

• Advanced epoxy/varnish methods to improve insulation and thermal conductivity.

• Optimizing outer casing design for higher thermal loads.

This leads to a longer lifespan and stable performance in the required conditions.

3. Electronics and Control

A modern motor doesn’t end at copper and steel; its brain is equally important. The co-design of motor and controller is where much of the efficiency gain comes from. A generic controller running a high-efficiency motor can still waste 10–15% of energy. An integrated design approach trims those losses and ensures smooth operation in the field.

4. System Level Optimization

A motor is never used in isolation. It always sits within a larger powertrain ecosystem, where its efficiency, reliability, and performance are directly influenced by the components it interacts with.

For example,

• In EVs it is about how the motor, controller, battery, and transmission work as a single unit.

• In Drones, its Motor + Propeller Aerodynamics, the thrust, vibration, and endurance depend on how well the motor’s torque-speed curve matches the propeller load curve.

Similarly, all other applications have their own system designs. To provide the best solution, we work to optimise for the system, not just the motor, ensuring real-world efficiency, durability, and performance.

Naxatra Labs: Engineering for Impact

Our philosophy is simple: design from the application outward, which is how we have built a base platform of motors for different applications.

• Antarix RF Series (EV Motors): Optimized for Indian traffic with thermal stability and regenerative braking support.

• Agricultural Motors: Field-tested for mud and water ingress with IP67 protection.

• Power Tool Motors: Compact, shock-resistant, and high torque-to-size ratio.

• Drone Motors: Deliver better flight endurance and lightweight.

By combining advanced R&D, material innovation, and OEM co-creation, we ensure that each motor is not only efficient but also perfectly matched to its intended environment.

Motors may be silent, but their impact is not. If EVs are the face of the clean mobility revolution, motors are its beating heart. As the world pushes towards net-zero goals, every kilowatt saved matters. Smarter, application-specific motors hold the key to unlocking these savings. Efficiency is no longer optional; it is the fuel of the future.

Also read: Naxatra Labs raises Seed Round to advance EV motor technology