Following on from using a Raspberry Pi to capture the electricity consumption of my home, I have over the last 2 years installed Solar Thermal Hot Water panels and very recently Solar PV. This meant that I had an opportunity to create something I had been looking to do for a while – an in house portable “Home Energy Centre”. This post documents the thought process behind what I did, the choices I made and also the problems and hurdles I had to overcome to get it all up and running. First let’s talk about the Home Energy Centre.
Hec-display in kitchen
This is built on a “Nook Simple Touch”, which I bought about a year ago during National Book Week for only £21!
Why did I choose this device? Several reasons really,
- it was cheap!
- It has built in Wi-Fi
- It is easily hackable (with Nook Manager)
- the battery life is good (about 1 week with wireless running all the time and the display refreshing)
- it has a touch screen
- it is small and can easily be mounted (either in a frame or on a fridge using magnetic adhesive tape)
- I can always re-use it as an e-book reader!
The “Home Energy Centre” (HEC) runs in the browser of the Nook. Because it runs in a browser it can also be displayed on any device with a browser, for example PC, Laptop, Mobile Phone.
The screen is split into 3 main sections.
The left hand section displays information on how the Solar PV panels are performing; telling me what Electricity is being generated now, if any is being exported, along with the totals for the day so far. This updates automatically reasonably frequently.
The middle column displays information on how the Solar Thermal Panels are performing, these provide hot water. So the display shows me, the current temperature of the panels, the current temperature of the water in the hot water tank; along with, the speed of the pump as a percentage and the number of hours the pump has run in total. The lower section tells you for how many hours the pump has run so far today, and importantly what the temperature gain in the Hot Water has been so far this day.
The right hand column displays the current weather for where I live.
Along the bottom are 3 “buttons”, for now only the left hand button works and this takes me to the graphs of electricity consumption I did a while ago (See this blog post). This information all in one place and readily visible has help us decide when to use electrical appliances in the house and when to or not heat the hot water using the central heating (Gas based) system we have in the house.
For more detail: Monitoring Room Temperatures with Moteino’s and Raspberry Pi