OpenEnergyMonitor is a project to develop open-source energy monitoring tools to help us relate to our use of energy, our energy systems and the challenge of sustainable energy. 

The OpenEnergyMonitor system is an end-to-end open-source energy monitoring system that is Arduino IDE compatible:

The openenergymonitor system is made up of four main parts: emonTx  |  emonGLCD  |  emonBase  |  emoncms. These can be assembled and configured to work for a variety of applications from a home energy monitor to solar PV import/export monitoring and more.

It is also possible to go beyond monitoring to start controlling things: diversion of surplus P.V energy to domestic hot water is an active openenergymonitor research project, see  Choosing an Energy Diverter, then Diverting surplus PV Power: Mk2 and Diverting surplus PV Power: PLL


Get started: Setup a system


Open Source

This is a project to build a fully open-source hardware and software energy monitoring platform.

We love open source and believe it is a better way of doing things.


Monitor and display electricity, solar generation, temperature and other environmental data with web-connected wireless sensor nodes based on the Arduino platform:

See Modules


Visualize, log and process your data with a powerful open source web-application called emoncms.

All the software and firmware is available on the openenergymonitor and emoncms github


We’re an active open research community of energy enthusiasts, engineers, programmers, makers pushing open source energy monitoring forward.

ForumsCommunity Blog Feed
OpenEnergyMonitor Blog


See what’s in the making and join in the development of an open-source sustainable technology.

In development: Wiki, Labs page



Open hardware, kits and components to build systems are available from the openenergymonitor online-shop.


Sustainable Energy

We’re interested in the use of monitoring technology to understand and optimise our energy consumption and generation. This allows us to approach the problem of sustainable energy in a logical and informed way

Sustainable Energy

Democratizing Energy Monitoring

Open-source monitoring hardware and software empowers us to be in full control of when, how and where our energy data is logged.

Join us

This is an open source collaborative project and we welcome your involvement. Through open source collaborative innovation we can make great technology.




Recent development commits

Watched repositories: emoncms, emonhub, openbem