While waiting for parts for the 45Mhz project (it takes weeks to get them nowadays), i dove into a home automation project i wanted to do.
Why? Because here in The Netherlands we use mainly natural gas for heating and cooking because we have (had) a hugh natural gas pocket underneath the north-east part of our country.
As this gas is running out now and is causing earth quakes in that part, the governement decided to start pushing everybody off the gas and into alternative energy by slowly triple the tax on gas and halfing it on electricity.
So everbody is looking on his own way to heat his house and we decided to use the surplus of our 6kWh solar system (24 x 250W panels) for (extra) heating.
That solar system was 8 years ago calculated for the 6kWh because then we on average use about 5700kWh/year.
Since then, because of led lamps and other energy efficient matters, we now dropped to about 3500kWh/year.
This surplus of 2500kWh/year is now retuned to the provider at a third of the costs (7ct/kWh) we have to pay for it when buying from them (22ct/kWh).
So we have 2500kWh/y to spend on heating next to the gas system so we bought 2 infrared heating panels, one 1000W, and one 700W to aid in heating the livingroom first.
To get a good insight in the kWh uses and the hoped for drop in M³ Gas, the need for a good home automation system arose.
I decided for DOMOTICZ.
They have a starter kit which includes a Raspberry PI with their Domoticz program which has a mass of sensors already implemented.
It runs as a headless system, so without screen, keyboard and mouse and is reachable by its webserver on every PC, laptop, tabled or smartphone and is placed into the metercloset where all the energy meters are.
This starter kit comes with a P1 USB cable (interface) to interface with the smart meters (via their P1 port) to monitor Electricity and Gas.
Its kind of plug and play and within a few hours i had the real time (10sec intervall) data for Electricity uses and Gas uses with nice graphs etc.
The Electricity shows the 4 counters we have (2 for incoming energy (high and low tariff) and 2 for outgoing energy (high and low tariff).
But i still missed the yield of the solar panels to see what is effectively used directly (most cost efficient).
We do have a solar data monitor system, but its in the metercloset and needs to be scrolled through by pushing a button there.
It does also have a webpage where you can login to show your average yield/day, month, etc, but is kind of slow (hours).
This solar data monitor system box has a led that pulses 1000 times per kWh, so i decided to use that pulse to interface with the Domoticz Raspberry PI as it has a pulse counter interface.
I bought a 5-port pulse sensor USB cable which is also supported by Domoticz, build a pulse detector using a photo transistor followed by a 555 timer to shape up the pulse signal (30ms pulses needed) and an opto coupler to isolate it.
This pulse was fed into the 5-port interface and connected to the Raspberry.
It now shows very accuratly the real time (10s) yield in watts and overall yield/day, month, etc. of our solar system.
Comparing the Gas uses, Electricity uses and the solar yield is now very easy as it is displayed on 1 web page.
Finally not because it was needed, but because i can (still have 4 counter ports left), i decided to try to monitor the water uses.
It seems that my watermeter has a hidden hole (covered) in which one can put a hall sensor which senses a magnetic field from a magnet placed on the half of the last digit (0.1L) disk in this meter.
So every 0.5 liter the Hall switches on and the next 0.5L off.
Again i used a similar circuit to shape up the Hall sensor signal with a 555 timer, but followed it by a 74HC221 to only trigger on a UP going pulse from the Hall/555 (verpies design, slighly modified).
The result is a pulse (30ms) every liter of water and again is passed on to an opto coupler into the 2th port of the 5-port pulse counter.
After some adjustments, the Domoticz now shows the water uses/day, month, etc. in liters and M³ water.
All in all i am pleased with this result and it shows during the last month that we are on the right track by using the surplus solar yield and dropping the gas uses by about 50%.
Video here:
https://www.youtube.com/watch?v=mYESkq3ahlcDashboard picture here:
Regards Itsu