In May 2020, we finally got our act together to have home solar (water is still gas). With a north facing aspect but a novel curved roof, we were able to implement 19 panels without degrading the roof line to the neighbourhood. Government rebates covered around 50% of the cost – total about $5200 for a 3-phase system.
Total output is intended for 5kW but because we’ve not sloped the panels for winter sun, the rates can be seen below. The Sungrow inverter is battery ready and we’ll explore in the coming months cost viability given no rebates are expected.
Implemented grid reduction
The largest contributor is heating (cooling) of any kind so look in those places first.
- Replaced 95% of lights with LED. Its common for 100Watt incandescents of halogens, so get rid of them. Choose LEDs that are (or have) Warm White at around 2700K to 3500K, Don’t buy Cool White at around 5000K to 6500K except for maybe kitchen/bathroom/garage work surfaces, but still consider reducing spectrums that have Blue Light
- To reduce Replaced 95% of lights with LED. Its common for 100Watt incandescents of halogens, so get rid of them.
- For the same Blue Light reasons, keep lighting low after sunset
- Run washing machines and dishwasher during the day
- Run Sauna during middle of the day.
- Run Dishwasher, Clothes Dryer during middle of the day.
- As mentioned we are gas hot water, so can’t benefit here.
- The Zip hot/cold/soda seems energy wasteful (more wasteful than a kettle), if I had my time again, I would NOT buy this.
- We opt for gas heating in winter.
- We have aircon but use windows mostly for cooling (being near the ocean) but obviously a Sydney Summer day with full sun is a good use of Solar to drive aircon.
- Water tank pumps are run on daytime cycles when needed.
- trickle charge of 12v backup power
Tracking Solar Production
iSolarCloud access (mobile App and comes with the Sungrow 3-phase invertor (SG5KTL-MT) that we used. The App shows live and historic generation.
This is an example chart from a cloudy day on the winter solstice. Peaks of 3.5KWatt around midday is because of our north-facing location with no shadows. We could improve the tilt of the panels.
The “Grid” number is bullshit, you need to buy a $700 addon to get that number right (see below usage tracking).
Trending downward into winter.
Tracking usage
I bought this gadget (Efergy Elite Wireless Energy Monitor) to track internal usage, you install it with some induction probes over wires in the meter box. I still recommend you should not do this yourself as that POWER WILL KILL YOU if you do the wrong thing, but it was easy to install.
The display sits in the kitchen, getting wireless signal from the meter box and you can see in real-time what appliances use juice. This is why its good to Sauna and run dishwasher/washing machine during the day. The Energy providers charge you 300% for electricity used vs solar electricity fed into the grid. Dickheads.
Apparently I can upload this data but have not got around to it. There are excellent conversations on Whirlpool (its like a Reddit for australian geeky home gadget DIY-ers) and my good friend Andrew Rogers’ site.
Battery/Off-grid
Did you know if the grid goes down, it takes your solar house down too? Google it. Apparently Bimodal inverters will work for both Grid and Off-grid systems, I’ve not had time to look into it as battery technology is still a high cost.