Harvy2 - battery-free LoRaWAN current sensor

Our sensor with four inputs for versatile monitoring

Harvy2 is a wireless LoRaWAN sensor of the latest generation for metering electrical currents and energy flows. It is versatile and easy to install. Unlike common LoRaWAN sensors, it does not require a battery or external power supply. Once installed, it runs autonomously and maintenance-free. This IoT sensor draws the energy it needs for operation from the magnetic field at the electrical conductor: it is sufficient to have an average current of 1 A flowing through one of the monitored wires. The principle behind it: Energy Harvesting.

One typical application of the Harvy2 is the metering of RMS currents in electrical mains, sub-distribution boards, or directly from the machines. Simply connect (up to) four deZem clamp-on current transformers to the sensor and clamp them on the desired wires - done! In addition, when using a deZem voltage converter, Harvy2 is able to determine the active power and many other parametres for each phase of the three-phase current. This data is transmitted to any IoT platform where it becomes visible and usable.

An intelligent event filter is integrated into the current sensor, which, for example, maps the inrush currents of systems accurately to the second. Alternatively, metering values can also be read out in a fixed time grid - even synchronously for metering values distributed anywhere in the world. All parameters may also be configured and firmware updates may be installed via an intuitive web interface. Decoders are provided by deZem for various IoT platforms.

All functions at one glance

Why Harvy2:

  • 4 inputs with polarised and strain-relieved plug connections
  • For current transformers up to 500 A (larger currents on request) or deZem voltage converters
  • Metering data: RMS currents, active power*, mains voltage*, power factor*, mains frequency*, etc.
  • Intelligent event filter: metering series (inrush currents, etc.) accurate to the second at a defined maximum rate**. 
  • Self-sufficient and maintenance-free (battery-free) 
  • Data transmission up to several kilometres and through thick house walls via LoRaWAN
  • Compact design
  • Flexible and quick installation without laying cables, e.g. via magnetic holder or top-hat rail adapter
  • Easy configuration and firmware updates via USB-C
  • On-site data visualisation via USB-C and web interface
  • Can be used with the deZem IoT platform and any other platform (JavaScript decoder freely available, e.g. for TTN, Chirp Stack, element iot)

* (available when using a voltage transformer - optional accessory)

** (available after one of the upcoming firmware updates)

Harvy2 Video

Harvy2: Versatile in use


Be it in facilities management, industry or smart cities: due to LoRaWAN, the Harvy2 current sensor is ideally suited for wireless data acquisition from electrical mains and sub-distribution boards as well as from widely distributed systems and other detectors. Because of its easy installation, its compactness and its freedom from maintenance, it can also be used in places that are difficult to access.

One typical area of application is the detailed analysis of the load profiles of, for example, air-conditioning and ventilation systems, also in combination with indoor air quality sensors. Ventilation and cooling, which account for up to 30 to 50 % of the electricity consumption in many larger buildings, are often particularly "low-hanging fruit" for a successful energy management. This means that the savings potential is especially high in these areas, as a reduction of the air exchange rate by half will lead to the electricity costs dropping to one eighth.

The Harvy2 is unparalleled in its effectiveness in detecting load peaks and base loads. Moreover, it can also provide significant support in the automated detection of anomalies and thus in predictive maintenance.

Easy installation


The Harvy2 is ready for use within a few minutes and requires no interruption of the power supply:

  1. Installation
    • Select a clamp-on current transformer of suitable size and connect it to the Harvy2 via a plug contact (up to four)
    • Clamp the clamp-on current transformer on the wire(s) to be metered
    • If desired, connect the voltage converter to one of the four inputs
  2. Configuration
    • User-friendly via USB-C
    • Set up with a few clicks 
    • When using the deZem IoT platform and/or DataSuite, all devices are set up in advance and are ready to use
  3. Utilisation of the metering values
    • Metering values immediately visible, both in the data platform and via USB-C
    • Access available across platforms via smartphone, notebook or desktop PC
    • Versatile analysis tools can be used with the deZem DataSuite

Our customers are excited

Bayer AG: "We particularly appreciate the simple, fast and uncomplicated setup of the metering points..."

"At Bayer's Berlin site, we have been using LoRaWAN technology with Harvys from deZem for energy management at selected locations since 2023. Our use cases so far are current metering such as temporary power measurements of machines for energy use/energy demand forecasts, the determination of savings potentials such as stand-by minimisation, as well as the detection of consumption peaks. We particularly appreciate the simple, fast and uncomplicated setup of the metering points in areas with good accessibility to the LoRaWAN gateways. We eagerly await the Harvy2's readiness for series production as a further development for an even easier set-up of metering points and for an even smarter application."

Smart City Cottbus: "deZem's analysis software gives us near real-time insight into our buildings."

"As a smart city, the city of Cottbus is focusing on a digital future. Even before digital energy monitoring becomes a mandatory legal requirement, together with deZem we have already equipped 32 building complexes with M-Bus data loggers or LoRaWAN gateways. These are used to monitor the electricity, heat and water consumption, temperatures, humidity and CO2 values of schools, day-care centres and administrative buildings. Knowing what consumption occurs when and what the conditions are in our buildings allows us to identify faulty operations and to save energy and thus reduce greenhouse gases and costs. The uncomplicated wireless technology LoRaWAN and deZem’s analysis software give us near real-time insight into our buildings."


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