I’ve been looking at flows (money, electricity, gas) this week and trying to make sense of the data I am receiving.
My electricity charges over winter are just under $20 per month. I was surprised it was this high but am pleased that it’s down from about $150 per month prior to my solar installation. The other advantage is the dramatic reduction in my petrol consumption now that I am mostly using my EV on my own solar. (I got to Ballina and back last week on one charge but my range anxiety kicked in when I got down to 8%.) I think I have filled up my old Honda once since April.
The Sungrow iSolarCloud software gives an estimate of net revenue from my solar feed in. However this is calculated on coarse grained estimations of feed in tariffs and does not cope with my energy provider’s (Amber) five minute pricing intervals. In any event feed in prices are generally terrible and one can get a nasty surprise when feeding in at 10 kWh when the price has just reached -4c per kWh at midday.
I’ve been working with Claude to get a more accurate estimate of my feed in and purchase charges but that continues as a work in progress. I am aiming to improve my feed in returns. When researching the various options I came across the German approach to domestic solar generation. Balcony solar took off when Russian oil and gas was cut to western Europe. Apparently many houses in northern Europe are south facing which is probably good for warming the house. This also means the roof has east and west orientations. This works well for them when energy prices are highest at sunrise and sunset.
The same applies in Australia where the recommended orientation is north. You might generate less energy over the course of the day with east / west panels but have increased amounts at peak times. I have even seen arguments suggesting west facing panels. You fire up the air-conditioning in the early afternoon so the place is cool when you get home from work.
There are many variables and they keep changing so it is hard to come to a firm conclusion as to the best course.
I did exactly this, and took the “as many panels on the roof as possible” approach rather than installing a battery. I have three sets of panels: east + north + west. The west panels run me through to about 10 minutes before sunset, which during summer gives me the ability to fire up all the air conditioning units for a half hour and cool the house down before solar generation stops and I have to start importing again.
After @GregY’s presentation a few months ago and his recommendations in the Solar Solution and Home Assistant thread, I reconfigured Home Assistant to do the calculations for me. I’m still on an old basic meter but I broke out the HA sensors into ToU brackets in order to get an idea of the import/export during the applicable time periods. I also added the daily charge as a dummy sensor to get an idea of overall cost per day.
This dataset has actually been incredibly helpful to run simulations against other electricity plans on the market to assess whether I should proactively move to a ToU plan or not (with the associated meter change) or how the landscape will look when I’m eventually forced onto a smart meter and the option opens up to me anyway.
Adding the sensors into HA and collecting the data yourself may be an easier starting point than trying to decipher it with Claude.
FWIW
if i did it again, i would have a largish west facing solar panel (mine all face north)
the changes in solar FIT and various other ToU changes make the landscape now very different to when i sppec’d it 9 years ago.
the FIT during day is now very low, so maximising overall solar generation is less important.
with the “peak” (4-9pm) bonus/high FIT - there is logic if you have a battery - to discharge during this period.
& hence having a good “late in the day” solar generation helps.
im finding that i can net feed in between 4-5pm from solar (15c/kWh) before sun dips .
and west facing panels would hel this enormously
if you want/need to rn A/C to cool the house for the evening, then once again hiigher “late efternoon” solar yield is beneficial.
smoothing the solar yield across the day - with a combo of west/north/east panels where possible is WAY better - partic if you dont have a battery.
that way you dont need to try to max out yur loads during ~1130-1330 period
.. and iit gives you great opportnity to use your solar rather than FIT for pennies.
also - there are some great simulators out there that help you model this - and yoou can see the yeld curvves and overall yield for various combo’s of east west north facing..
also you can see the tilt yield curves - relevant if your considering rack mounted (eg for a flat roof house)