IoTaWatt is an open source/open hardware electric energy monitor project. Both the firmware and hardware design are freely available to anyone. This site makes available a commercially manufactured version of the open hardware along with various voltage and current sensors needed to assemble a working energy monitoring system.

The IoTaWatt base unit can be used with dozens of voltage and current sensors, from a variety of manufacturers and available from this site, eBay, Amazon, Ali Express or direct from the manufacturers. While there is a class of users who have built their own IoTaWatt hardware, this commercially produced version has been tested to applicable UL, FCC and CE standards and is pre-loaded with firmware. Thousands have been installed in over 60 countries on four continents.

The approach is different from commercial systems that keep all data in the cloud with proprietary analysis and reporting tools. IoTaWatt is a standalone solution with a built-in webserver that stores years of high-resolution data locally and supports local data analysis and reporting. At the same time, it can also automatically and seamlessly upload to popular energy reporting systems and database systems hosted on your local server or in the cloud.

The design of IoTaWatt is versatile, measuring electric power anywhere worldwide using external voltage and current sensors. It is in widespread use in both 120V and 230V countries with both single phase and three-phase supplies and also used with commercial and industrial 277V/480V and 230V/400V three-phase.

More information can be found in the project website. Installation and use are documented online. The community forum is available for advice and support.

IoTaWatt is not for everyone, and it’s not a phone-app toy. It requires an electrician or modest electrical skills to install in the load-center, and the resulting measurements require some general understanding of energy principles as IoTaWatt focusses on fixed metrics like Volts, Watts, kWh, VA, etc rather than the varying monetary cost of the energy.

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IoTaWatt Base Units are currently out of stock. Check back around January 30.

The store is undergoing renovation during the out-of-stock condition. Will be accepting orders again when base units are in stock.