The most practical thing I’m thinking of is to deal with the septic system at our retreat centre. The centre has a large array of solar panels and the septic system basically runs 24/7, constantly pulling 4kW. While that might be ok if the facility was fully utilised, much of the time it’s just the caretakers doing maintenance and some of the monks (yes, I’m a monk) working in the office in the morning.
So what we’re thinking about is to have a simple way to control and monitor that individual device. So, a relay and arduino? Maybe, but then I got interested in Mozilla’s IoT project.
A simple prototype could be hacked together with a smart plug (the TP-Link WiFi Plug is easily available at the Australian big box store Office Works) and a Raspberry Pi. To start with it could be configured with some timing rules, but it would be great to have some feedback on energy usage.
Lately I’ve been learning Django, so what comes to mind is a microservice to keep track of kW/h used per interval. This same information can be obtained from the solar inverter to compare production and consumption of electricity, though at this time we’d have to use proprietary software and bluetooth to download the production numbers as a CSV file. That kind of sucks, but perhaps the makers of the inverters will come up with a better, more open way to access that data.
Solar Analytics makes all of this easy. A device sits in your meter box and measures grid imports/exports. You can also monitor individual circuits (such as our septic system) or hot-water systems (a battery itself really). Other devices include solar diversion - excess energy can be sent to an individual circuit, such as a hot-water system or your shiny new Tesla Model 3 (well, one can dream).
So these Things exist, connecting them to the open web is the trick.
