IoTaWatt is an open-source, open hardware project to produce an accurate, inexpensive and easy to use energy monitor. It can use any of dozens of common current transformers and will report the data locally via integrated web server, or upload to any of several third-party energy websites/data bases. Configuration and administration is through an easy to use browser based utility running on a computer, tablet or smartphone.

IoTaWatt is a full function standalone energy monitor with the capability to store and serve up to 15 years (or more) of comprehensive usage data and has an integrated web-server with visualization apps. At the same time it can upload data to any and all of several (and counting) web based database and reporting systems.

Hardware is open and uses an ESP8266 nodeMCU, MCP3208 12 bit ADCs, an RTC, and an SDcard. The commercially manufactured unit is tested and certified to UL standards in the US and Canada, CE compliant, and FCC compliant and comes with a custom enclosure and wall mount.

Metrics accumulated to 5 second resolution are Voltage(V), Power(Watts), Energy(kWh), VA, and PF. While not certified to a standard, users typically report accuracy within 1% of their revenue meters.

With over 1,000 units sold worldwide over the past year, it's now starting to get the attention of energy professionals.

The software project is not commercial, however it was necessary to establish a legal entity (IoTaWatt, Inc.) in order to manufacture, certify, and sell the hardware worldwide. There is an investment in that infrastructure that needs to be recovered through sales. You can visit the IoTaWatt Stuff Store to get one.

The unit is manufactured in the USA.

• Documentation
• Project Website
• User Forum