This is the perfect project for the energy conscious gadget geek homeowner or business. As we know energy efficient homes normally have solar panels installed. In Australia normal retail Feed In Tariffs (FIT) for solar are lower than your normal usage tariff so it is wise to try and use power generated from your own solar system first and limit power use from the grid.
If you want to change your habits and reduce your power bill and become more sustainable, you really need to know your generation in real time. That’s where this real-time energy display comes into play.
Built from 32×64 RGB matrix LED panels connected to a Raspberry Pi, it connects to your home network and grabs data directly from your inverter and AEMO’s website. AEMO is the Australian Energy Market Operator and controls the wholesale electricity costs in the NEM (Nation Electricity Market).
The top line shows the instantaneous power being generated followed by the daily generated energy (Right) for that day. These figures are very useful and come directly from your inverter.
The middle line is displaying the mains voltage and frequency at the inverter. The voltage is important as there is too much solar generation in some areas and this pushes up the voltage. If the voltage gets too high the inverter is programmed to reduce the power it is generating or in some cases, total stop generating until the voltage is reduced. It’s becoming a very common issue that I have during low demand months in Spring.
The bottom line is showing the spot wholesale electricity price and the total demand for the state. In this case both values are for South Australia. This data is pulled from AEMO in near real-time. Why is this important? Well some companies like Amber Electric now offer wholesale energy prices that change in each 30min internal. For switched on energy users, they can save lots of money but using electricity when prices are cheap or even negative (Yes, retailers can be paid for you to use electricity) and reduce their usage when prices are high.
The software is a simple custom python script that gets the data of interest and then uses a library called LED_Matrix written by Henner Zeller to display it. I can also display my import and export to grid data if required, however I show this on a Android Dashboard.
The hardware uses a Raspberry Pi 3B with a custom designed interface board for the display control. A red button can be used to shutdown the Raspberry Pi’s OS before removing power however this is not really needed.
This display can be reprogrammed to display anything from graphics to stock prices etc. If there is an API to get the data, it can normally be displayed. The possibilities are endless.
Specifications
| Pixel Count | 32×128 pixels |
| Size | 670l x 185h x 90w |
| Power | 5V, 2A |
| Connectivity | Wi-Fi or Ethernet |
| Processor | Raspberry Pi 3B |
| Inverter compatibility | Fronius |
For more details or to place an order email info@embedtronics.com