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.

  • Wireless sensor nodes sending data to a web-connected Raspberry Pi base-station.  
  • Supports home energy, solar PV system & remote temperature monitoring plug-and-play out of the box.
  • Fully open-source hardware & software, Arduino IDE compatible
  • Easily customized for a variety of applications.

Setup Guide

Online Store



emonPi Kickstarter

In April 2015, we ran a Kickstarter campaign for our new all-in-one Raspberry Pi based energy monitoring unit raising £24,723! Thank you very much to everyone who backed us and helped spread the word. You can see the emonPi Kickstarter page and video here:



The emonPi is now available for purchase through our online shop

Click here to download a OpenEnergyMonitor system overview document (.pdf) - updated Oct 2015

Solar PV diversion
An active research project is the diversion of surplus PV system energy to a domestic water heater. See
Choosing an Energy Diverter, then Diverting surplus PV Power: Mk2 and Diverting surplus PV Power: PLL

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:

Hardware Modules, Hardware Wiki


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

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.



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

In development: Labs page



Official online store. Support the project by purchasing pre-built units, kits and components to build systems from the OpenEnergyMonitor Online-Store.


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