The latest lower in rooftop photo voltaic feed-in tariffs and the looming risk of a photo voltaic tax are sparking concern amongst solar energy customers.
In Victoria, the minimal feed-in tariff was just lately decreased to three.3 cents per kilowatt-hour. In New South Wales, IPART forecasts photo voltaic exports can be value between 4.9 to six.3 cents per kilowatt-hour in 2024–25, down from 7.7 to 9.4 cents in 2023/24. These adjustments make it essential to optimize photo voltaic power utilization at dwelling, particularly for electrical car (EV) charging.
Throughout much less sunny months, charging your EV at an equal price all through the day is just not environment friendly as a result of your photo voltaic system produces extra power round midday than within the morning or afternoon. This implies you could be exporting kilowatt-hours at a low feed-in value round mid-day after which shopping for again power at the next value later within the day. Aligning your EV charging occasions with peak photo voltaic manufacturing may also help you keep away from this difficulty.
Nevertheless, establishing an optimised photo voltaic system for EV charging could be costly as a result of want to purchase particular chargers, dwelling batteries, or meters, all from the identical producer. And doing all of it manually is a big problem – who has time to commonly test for the solar and modify the charging all through the day?
As an alternative, many householders have already got all the mandatory gear via their private computer systems. A PC may handle and optimise photo voltaic power use, making further expensive gear pointless, if solely it had entry to all of the gadgets.
I’ve tried this out utilizing the Tesla API and the Fronius Inverter API on my Mac, and efficiently managed to get to ’sensible charging’. Now, based mostly on the photo voltaic output (learn from the Fronius API), and if the battery is beneath 80%, the Mac tells the Tesla to begin charging (through the Tesla API).
If a cloud passes by it is going to scale back the charging present after which enhance it once more when the solar is again. It is a extremely environment friendly option to cost, and on a typical day in Spring would save about 5$, in comparison with plugging in in a single day. All by making the prevailing gear smarter.
There are nonetheless some limitations: Accessing detailed energy influx and outflow information from Good Meters could be difficult, as some energy corporations solely provide this information in CSV recordsdata, not via APIs.
So I can not simply learn the precise, real-time use of the house with software program. It additionally solely works with some manufactures, I haven’t but gone via all of them, however from a number of checks I discovered that many automobile makers are nonetheless on the stage of creating such APIs, fairly than having them up and working.
These limitations underscore the necessity for open requirements within the power sector, and a few efforts are underway globally beneath the banner of “Open Power”. Future requirements can be useful, if they allow us to seamlessly combine all our power gadgets into a sensible and environment friendly dwelling.
I’ve included hyperlinks to the 2 APIs from Fronius and Tesla beneath to get you began. I’d additionally invite the group to assist me test if we are able to additional construct out such software program. Proper now, it really works for me, however it could be nice if we may make it extra sturdy, in order that anybody may set up it.
This might simply improve dwelling photo voltaic techniques and make optimised EV charging extra accessible. Should you’re , dwell in VIC Bayside or Glen Eira, and have the same setup to mine (Tesla, Fronius Inverter, Tesla Wall Charger, Apple Mac laptop), please contact me at [email protected].
Hyperlinks to technical documentation: