Introduction: Innovations for the industrial production of Ukraine
Industrial production in Ukraine, as in the whole world, faces an urgent need to increase efficiency, reliability and reduce operational costs. Condition monitoring (CM) of equipment is a key tool to achieve these goals, enabling the transition from reactive to predictive maintenance. However, traditional wireless sensor monitoring systems often depend on batteries, which creates significant operational challenges: regular replacement, disposal, logistics, and failure risks due to battery depletion. This is especially true for hard-to-reach or dangerous areas.
Energy Harvesting Sensors (EHS) technology offers a fundamental solution to these problems. It allows sensors to function completely autonomously, using energy from the environment - vibration, heat, light, radio frequency radiation. This paves the way for truly fail-safe condition monitoring, which is critically important for ensuring the continuity of production processes and increasing the competitiveness of Ukrainian enterprises.
Scientific basis: Principles of energy harvesting for sensor systems
Autonomous sensor systems with energy harvesting are based on the conversion of various forms of environmental energy into electrical energy. The main principles include:
1. Vibrational energy harvesting
Vibration is one of the most common sources of energy in industrial environments, especially for rotating equipment. Two main methods are used:
- Piezoelectric effect: Some materials (for example, ceramics based on lead zirconate titanate, PZT) generate an electric charge when mechanically deformed. Piezoelectric vibration generators usually consist of a cantilever beam with a mass at the free end, on which a piezoelectric element is fixed. At the resonant frequency of equipment vibration, the generator produces maximum power. Typical output power can be from 50 μW to 500 μW at accelerations of 0.1-1 g and frequencies of 50-200 Hz in a volume of 1 cm³. The conversion efficiency can reach 10-20%.
- Electromagnetic induction: The movement of a magnet relative to a coil (or vice versa) induces an electric current according to Faraday's law. These systems are often larger, but can generate higher power (up to several milliwatts) at lower vibration frequencies and larger amplitudes.
2. Thermoelectric energy collection
Thermoelectric generators (TEGs) use the Seebeck effect, converting the temperature difference between the two sides of the device into electrical energy. They consist of serially connected p-n junctions of semiconductor materials (for example, bismuth-telluride). Industrial processes often create significant temperature gradients (e.g. hot pipes, engines, furnaces). TEG can generate 10-100 μW/cm² at a temperature difference of 10-50 °C. Conversion efficiency is 2-5% for commercial devices.
3. Photoelectric energy collection
Solar panels (photovoltaic cells) convert light energy into electrical energy. Although they are most efficient in direct sunlight (up to 10-20 mW/cm²), today's highly sensitive cells can generate enough power even in low indoor light levels (eg 10-50 µW/cm² at 500 lux). This makes them suitable for monitoring in factory shops with artificial lighting.
4. Radio frequency (RF) energy harvesting
RF energy harvesting uses electromagnetic waves (for example, from Wi-Fi routers, TV towers, special transmitters) to power low-power devices. This is implemented using rectennas (antennas connected to rectifiers). The power harvested is usually very low (a few nanowatts to microwatts) and strongly depends on the distance to the source and its power. This method is mainly used for very low power sensors or as an auxiliary power source.
Energy storage systems
Since energy sources can be intermittent, energy storage is necessary for the stable operation of sensors. Usually used:
- Supercapacitors: High power density, fast charge/discharge, very long life (over 100,000 cycles), but lower energy density compared to batteries. Ideal for buffering energy.
- Thin-film batteries: Compact, safe, long service life (thousands of cycles), low self-discharge. They are used to store larger amounts of energy.
Modern microcontrollers and wireless modules (e.g. Bluetooth Low Energy (BLE), LoRaWAN) consume minimal power, which allows them to operate from harvested energy. The average consumption of a vibration sensor with data transmission once every 5 minutes can be 10-50 µW.
Current State of Development and Technology Readiness Level (TRL)
Energy harvesting technologies for industrial condition monitoring are at different readiness levels (TRL) according to the methodology of the European Commission:
- TRL 5-6 (Technology tested in a suitable environment): Piezoelectric and thermoelectric generators for vibration and heat are already successfully integrated into prototype sensor modules and tested in real industrial conditions. For example, vibration sensors powered by vibration of bearings, or temperature sensors powered by thermal gradients on pipelines. Companies such as Analog Devices, TE Connectivity, Würth Elektronik are actively developing components and modules.
- TRL 7 (Prototype system demonstrated in operational environment): Some complex monitoring systems using combined energy sources (eg vibration + sunlight) have already demonstrated stable performance at pilot sites. Examples include monitoring the condition of remote pumping stations or elements of bridge structures.
- TRL 8 (System Complete and Certified): Separate commercial products for niche applications (eg wireless tire pressure sensors, powered by rotation) are already available on the market, complying with CE and UkrSEPRO standards.
Key market players include both specialized startups (e.g. Perpetuum, Cymbet) and large industrial conglomerates (Siemens, Bosch, ABB) that integrate these technologies into their Industrial Internet of Things (IIoT) and predictive maintenance solutions. Developments are focused on increasing conversion efficiency, miniaturization and integration with advanced wireless protocols.
Potential Impact on Maintenance and Repair (MRO)
The introduction of energy-harvesting sensors will have a transformative impact on MRO practice:
- Reduction of operating costs: The most obvious advantage is the complete exclusion of costs for the purchase, replacement and disposal of batteries. For a large enterprise with thousands of sensors, this can be up to €50-150 per sensor per year, including the cost of batteries and labor. It also reduces administrative burden and logistics costs.
- Improving monitoring reliability: Eliminating the risk of sensor failure due to battery discharge ensures continuous data collection, which is critical for early fault detection. Sensors can be installed in previously inaccessible or dangerous locations where battery maintenance would be impractical or dangerous.
- Advanced analytics and predictive maintenance: A constant stream of high-density data from autonomous sensors will enable the use of more sophisticated machine learning algorithms to analyze equipment health, predict failures with higher accuracy, and optimize maintenance schedules. This will help reduce unplanned downtime by 15-25%.
- Environmental advantages: Significant reduction in the volume of hazardous waste (used batteries), which meets modern environmental standards and requirements (for example, ISO 14001).
- Resilience and security: For Ukrainian enterprises operating in high-risk environments, the ability to deploy fully autonomous monitoring systems without the need for regular intervention is key to increasing operational stability and personnel safety.
UNITEC-D GmbH, as a global authority in MRO, plays a critical role in this transition. We not only supply high-quality industrial spare parts that comply with EN and ISO standards, but also actively integrate new technologies into our offer. This includes components for energy harvesting systems, compatible sensors and solutions for retrofitting existing equipment to support fail-safe condition monitoring. Our expertise in the selection and supply of components that meet the requirements of DSTU, CE and UkrSEPRO ensures the reliability and compatibility of new systems.
Timeline and Implementation Curve: Realistic Expectations (2026-2035)
The introduction of energy-harvesting sensors into industry will be gradual, but steady:
2026-2028: Early adopters and niche solutions
- Focus: Critical equipment in hard-to-reach, dangerous or remote locations where the cost of replacing batteries is prohibitively high (for example, condition monitoring of turbine bearings, valves in chemical plants, elements of bridge structures).
- Technologies: Mainly vibrational and thermoelectric energy harvesting. The initial cost of EHS modules will be 30-50% higher than traditional battery modules, but the return on investment (ROI) for these niche applications will be 2-4 years due to significant maintenance savings.
- Standardization: Strengthen the development of industry standards for EHS interfaces and protocols.
2029-2032: Advanced implementation and integration
- Focus: New industrial facilities and large-scale modernization programs. Wider application in rotary equipment, HVAC systems, pipelines.
- Technologies: Development of combined energy harvesting systems (eg vibration + heat + light) to improve reliability. Miniaturization and efficiency improvement. Reduction of the cost of EHS modules by 15-25% compared to the initial stage. Payback for most applications will be 1.5-3 years.
- Integration: EHS sensors are becoming a standard component of IIoT platforms, providing a continuous flow of data for predictive analytics.
2033-2035: Mass adoption and dominance
- Focus: EHS sensors are becoming the de facto standard for most new and upgraded condition monitoring systems. Wide application in all sectors of industry.
- Technologies: Further miniaturization, increased conversion efficiency (up to 30-40% for vibration, 7-10% for thermoelectricity). The cost is close to traditional battery-powered sensors, making the TCO much lower.
- Autonomy: Development
