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Friday, June 17, 2016

A real-time energy display for my solar power system

http://www.mpja.com/Digital-Panel-Meters/products/52/

Ever since one of my electronic parts suppliers (MPJA) got in a line of cool blue digital meters, I have been applying them everywhere.  See my recent blog posts describing the gauge I added to my solar charged electric lawnmower, and temperature gauges that I added to my solar hot water heating system.

When I give a tour of my renewable energy systems, I point to the circuit breaker panel where the 240 V AC comes in from the roof mounted solar array and feeds out to the main breaker panel.  

Breaker panel, new meter (circled) and Envoy
Next to it (the white oval device) is the Envoy web Gateway for the Enphase microinverters on the roof.  

Envoy Enlighten live web portal
The Envoy allows real-time monitoring of every solar panel and creates a live web portal (that I embedded in my web site) showing performance of each panel and how many watts it is producing right now and over time.  The problem is that the Envoy only shows total wattage in a small hard to read small display, along with a few other statistics like the number of microinverters reporting and the total megawatt hours produced. 

What I needed was something that can be seen easily that shows the amount of power my array is producing in real time.  So I installed a multifunction meter (circled in the image above) that displays  Volts, Amps Watts, and kWH on a clean brightly lit display:
Now it is easy for me to tell people as I show them my system that it is currently generating 4497 Watts, and if a cloud goes by one can see the numbers changing dynamically.  The number at bottom right shows kWh since the meter was last reset (= 1.6MWh).  My system generally produces between 4 and 5 MWh per year.  As a geek, I have to admit that I am a sucker for a sexy blue techno glow display!