Advice with Consumption data recording and upload

Topics: 1. General
Jun 26, 2016 at 10:46 AM
Edited Jun 26, 2016 at 3:16 PM
I have been a user of SBFspot and PVOutput since my PV system was installed to record my generation statistics. I am now looking to automatically collect and upload my consumption data so that I can view and compare the usage from PV and the grid.

If any users would be so kind as to inform me the equipment and methodologies they have implemented to achieve this I would be very grateful. I do not have a smartmeter as yet if that makes any difference ?

On separate not I am also looking to utilise as much of my PV generated energy rather than exporting by implementing a device like the ImmerSUN / SOLiC 200 / Solar iBoost devices is any one using these devices are they worth while / cost effective ?

Thanks in advance

Simon
Jun 28, 2016 at 7:37 AM
Yes I've done that, I have a system that runs alongside the SBFspot on the PI. My target was to use as much of the solar power available as possible for hot water, heating and/or cooling the house, pool pump operation and enviro pump operation in a set and forget mode. For instance if the washing machine is running during the day there may be a spare 1KW or more at any one time which could be used for a heater or aircon so the the unit calculates this (every 3mins) and acts accordingly.

All the units are home built except for the wireless sockets. The system consists of the Pi computer as a webserver, a WiFi meter reader unit, client-side WiFi devices with relays, portable wireless sockets and contactor(s) to drive the HWS and the Pool Pump. The contactor is used for appliances that are permanently wired or are essentially high power or heavily inductive devices such as a HWS and/or Pool Pump and they just slot into the power breaker box and they also have a manual override switch (recommended).

It all works extremely well switching appliances on and off as surplus solar power and your settings dictate. In addition the system also provides 5 timer schedules for each appliance connected which may switch appliances on or off at any time of the day regardless of solar power. Power usage graphics also show each appliances use throughout each day.

I had a digital Smartmeter installed (Landis Gyr) by the power company so I could switch to Time of Use metering (TOU) which provides half-price electricity from 22:00 - 07:00 every day and half-price ALL weekend (NSW, Australia). These meters also have flashing LED's to indicate how much power is being imported/exported so it is easy to calculate exactly how much power is being consumed or wasted. I have a small WiFi SOC unit (ESP8266-12e) in the meter box with 2 light sensors attached to the smartmeter one a standard sensor to read the flashing LED and an infra red sensor to determine whether import or export (the IR is not advertised by the power company!). The power consumed is a product of either Solar power + imported power OR Solar power - exported power. The solar power is grabbed from the SBFspot utility and the import/export power from the meter unit and then calculated (accurately) and uploaded automatically to PVoutput every 5 minutes. If power is being exported this is the trigger (read every few minutes) to calculate whether or not any appliance(s) may be be switched on. If imported power then it calculates what if any to switch off.

My WiFi client-side units (ESP8266 SOC) drive two relays which will provide two contacts and these I use to drive the Air Conditioners directly as the relay contacts are connected across the LV start switch of the aircon via a simple plug/socket lead from the client-side unit. I recommend using the ESP8266-12e (kit or nodeMCU version as it is called) in these units as they are extremely easy to reprogram any changes you wish to make to the software taking only a minute or so to do.

The WiFi client-side unit also incorporates a 433Mhz wireless transmitter as well to drive standard portable wireless sockets which are available at many stores and I have previously detected and preprogrammed the socket trigger codes into the client-side software. So a client-side WiFi command may be used to trigger the relays or may be onpassed to the wireless devices to trigger the sockets thus providing a small wireless cell network within your home. All these units are very cheap to build and the power savings will in any case save you 1000’s. over the long term.

The HWS is a big consumer of power and used every single day so I would recommend changing the HWS element to match the wattage to that of the expected average solar power output of your system or less. I have a 4KW system (mid-coast, Australia) and I changed my element from 4.8KW to 2.4KW so now even in winter the power required is mostly always fully covered by the solar output hence saving 100's of KW per year.

Photo's of the above and sample pages are on my PVoutput page (Daves SMA) at http://pvoutput.org/list.jsp?id=43800&sid=40003

The project is open source with software and instructions which can be downloaded from https://github.com/infinityab/Solar-IOT

I would appreciate any input and ideas from anyone.

Dave