Networked Solar hot water controller, Solar PV monitor and Home Electricity monitor

Case Study: ogoronwy house sustainability project



System schematic


Network documentation page

PV monitor and simple charge controller unit

The unit consists of:

  • Battery Voltage sensor - simple voltage divider
  • Load Current sensor - Allegro ACS715 cool components
  • Generation Current sensor - Allegro ACS715 cool components
  • 12V Automotive Relay module with TIP121 driver
  • Barebones Stripboard Arduino (Suneil's good work)
  • 74AHC125 tristate buffer for network functionality

Left: The PV panels - courtesy of Ken Boak who has kindly lent me the panels 

Middle: The PV monitor + charge control unit + ken's semi-hacked UPS inverter

Right: A closeup of the electronics

Arduino sketch for the above

Download: SolarPV30Nov.tar.gz

Template sketch for networked slaves:

Download: SlaveTemplate.tar.gz

Browse software in repository : software repository

Solar hot water controller and energy monitor unit

To build:

1) Follow guide on building a solar hot water controller here: Solar hot water controller v1.1

2) Follow guide on building a home energy monitor here: Mains AC energy monitor

3) Link both of the above to the same arduino

3) Download sketch for Solar hot water controller + Energy monitor unit configured as a slave

Download SHWEmonUnit26Nov.tar.gz : software repository

Master + ethernet unit

Template sketch for requesting data from slave units and forwarding the data via ethernet to web server: 

Download MasterEthernetTemplate.tar.gz

Example sketch for implementation above:

Download MasterPVSHWExample.tar.gz

Browse software in repository : software repository

Web logging and graphing

I've written a mini guide here on implementing web logging and graphing to which the above links up too: Web Logging and Graphing

Further development

  • Would be great to have Relay module, PT1000 module, energy monitor module all PCB'ed up with standard 3 or 4 wire connectors for simple plug and play hardware setup. Using the same connectors as nuelectronics do may be a good idea to have compatibility.