The eGauge is an energy monitor that uses power line communication to send data from your home's breaker panel over your home's electrical wiring to the HomePlug adapter, and then to your computer through a wireless modem.
From the eGauge overview page:
"eGauge is an affordable, flexible, secure, web-based electric energy and power meter that can measure up to 12 circuits on up to 3-phases (120V−480V, 50−60Hz). Use it to measure and record whole-house consumption, solar, wind, and other renewable electricity generation, measure consumption of individual loads, such as appliances or the consumption of geothermal system pumps and backup heaters. The data can be viewed on any web-enabled device through the built-in web-server. The display is updated every second, giving immediate feedback on any load or generation changes. The device records the most recent 30 years of data in its built-in solid-state memory. The measurements can also be accessed through BACnet and/or can be pushed to a server via our XML API."
And in terms of measuring capabilities, also from the Overview Page:
"eGauge samples each measurement channel several thousand times a second in order to calculate real power (what the utility bills you for), apparent power, True RMS voltage, and current. The high-frequency and simultaneous sampling allows eGauge to establish the phase-relationship between the voltage and current channels and therefore it can detect which direction power is flowing (e.g., from grid to house, when power is being consumed, or from house to grid, when renewable-energy generation is greater than usage in the house).
Once a second, eGauge updates the following quantities:
- Line frequency in Hertz (one measurement).
- True RMS voltage in Volts (one measurement per voltage tap).
- True RMS current in Ampères (one measurement per CT).
- Real power in Watts (one measurement per voltage/current pair defined in the device configuration).
- Apparent power in VA (one measurement per voltage/current pair defined in the device configuration).
- Power factor (one measurement per voltage/current pair defined in the device configuration)."
Data is hosted on the eGauge website FOR FREE through a robust web hosting page.
There is a great support page and eGauge is sold on their website in the eGauge store. What's nice about the eGauge is you can select several differet current transformers depending on which one best fits your need. You can also buy a kit that includes everything you need to get started.
Kit includes:
- eGauge device
- HomePlug adapter
- 2×100A/0.75" CT for monitoring house consumption
- 1×50A/0.4" CT for monitoring solar or appliance
