The best way to start is to browse through the following build guides and choose which system best suits your needs:
Home energy monitoring
Mains AC energy monitor v3.0 - basic setup - If you just want to get a basic energy monitor running on a breadboard with an arduino start here.
SD Card Logging Power Monitor with LCD - Non-invasive AC power meter which logs the data to an SD card with a time stamp from a real-time clock chip. Data is displayed on LCD screen.
LCD Power Meter - by Matt Hodge
Solar PV monitoring and control
Solar Power Manager - 2 channel non invasive power meter with LCD, which diverts unused solar power to heat domestic water.
PV System Monitoring - 2 channel non invasive with Graphics LCD & External Temperture based on EMONTX & JeeNode
Wind power monitoring
Data logging for wind speed (and DC current using invasive hall sensor) - For monitoring the windspeed and power output of a small wind turbine. Data is logged to SD card.
Inverter or other interface
Extracting data from SMA SunnyBoy PV Inverters (Bluetooth) - by Stuart Pittaway
Extracting data from an SMA webBox - by Carlos Alonso Gabizó
Tutorial - programming a Nanode using Arduino board - No FTDI cable? step by step guide to programming using a Arduino board
Ogoronwy house sustainability project – by Trystan Lea
Cambridge Sensor Kit (CSK) Energy - build upon OpenEnergyMonitor design
Bee hive monitor - by Glyn Hudson
Add your build here: We would love you to hear what you have been building with OpenEnergyMonitor, 3rd year 4th year project? Home monitoring systems? To add your build here: log in and then click on edit at the top of the page, add a link to your build page (you can create this on the site here by clicking on create content or if you have your own page just link through to it here).
Old build documentation, systems that have since been superseded by new energy monitor builds:
Other projects that might be useful
The free charge controller project - A project to develop a maximum power point tracking charge controller, ideal for wind turbines, solar PV etc