I thought I’d start a thread around this service, it’s Home Assistant integration, and what I use it for.
I use Home Assistant and a PV system (Victron based), and found the Solcast service and custom component somebody developed for HA extremely useful:
Solar Forecasting & Solar Irradiance Data (solcast.com)
Solcast discussion on Home Assistant Community (home-assistant.io)
It (Solcast’s website + the customer component) allows you to:
- register a free residential service with your system details (location, AC/DC system side, angles etc.)
- submit readings from your system to “tune” their prediction model towards your actual system
- request an estimated PV yield for the rest of the day (up to 10 or 20 times a day for residential accounts), taking into account estimated cloud coverage, location, time of day, time of the year etc.
So I use it to boost my geyser’s temperature:
- when my batteries reach 100%, ask the Solcast sensor for the estimated PV yield left (for my system, for today)
- when there’s enough, run the geyser for 15 mins. It is a 4kw element, so it uses 1 kWh.
- repeat until the geyser is super hot (70 degrees in my case) or there’s not enough PV yield left (3 kWh in my case) – that way I get to “store” more of my PV energy and keep the geyser hot for subsequent cloudy days.
Of course, you do not need to use it with a geyser (I had to get the temperature of my geyser into HA too). You can use it to run a borehole, run an aircon, run a crypto miner etc. using your “free” energy.
Here’s my forecast for the rest of the day (and tomorrow and the day after):
And here’s the Solcast website’s own forecast graph, and how I “tune” their model to my system: