I started a journey for renewable energies when I received 5 KWP Solar -PV cells and a home battery in January 2019 and in September of the same year my first electric vehicle, a Tesla model -3 output.
I later improved to a model -Y performance. It is easier to deal with it.
My battery is a sun Eco 9.43 (German company), originally a 10 kWh (9 usable) can be used to 15 kWh, 13.8 kWh. It is only a maximum of 3.3 kW, so it is not powerful according to today's scales, but has a bit of capacity.
I used this system in self -consumption mode. Here the battery loads when the solar energy above what the house draws is available, and it is preferred to pull out of the network when energy is needed in the house.
I sometimes invited the car from the wall charger (single -phase ~ 7 kW), which was delivered by car. In those days, Tesla included a wall charger with its cars (as well as the mobile charger), but I had to pay for the charger installation.
Most of the time, however, I have been calculated on free chargers at four different locations, all of which are from home with a few minutes by car (luck, I think). Three 11 kW target charges and a NRMA 50 -KW -DC charger. So I usually walked the car for free, exactly the street.
I started the solar system and the battery for the normal tariff and the feed -in tariff of the electricity company, with which I was previously. My electricity bill fell from around $ 2,600 per year to around 750 US dollars.
That was great for a while, and then I heard of virtual power plants, so I registered with Sonnen's VPP, the $ 49 a month for up to 7,500 kWh per year and some feed-in rate that I cannot remember. This further reduced my bill. Fantastic!
Then I came across a problem. More and more EVs, where they walk onto the street and discovered the free chargers, and these free chargers disappear (only two destinations that are left near my house).
In addition, my VPP energy cap of 7,500 kWh Pa, which I have already hurt a little, made the loading of a car at home an expensive option or at least more expensive than I was used to.
The one over the upper limit over the cap was ridiculous at 40 cents (if I remember properly) that I cost about 32 US dollars to fully charge my car, which had a range of about 530 km WLTP with its 77.8 kWh battery.
What should I do? I then learned from the new retailer Amber Electric, which loads a flat rate per month (originally 20 US dollars) Plus Daily Grid Connection (about 80 cents per day), and you will then be exposed to the national tariffs of the national energy market (or nem).
These tariffs change constantly and vary greatly from negative numbers such as -10 cents to positive numbers such as +19 USD per kWh (WOW). It's like the stock market, buy it deep and sell high. It seems to be called Spot Trading.
They offer their own software solution to charge your battery and car to meet this volatility and try to earn money through this spot trade. I understand that this is pretty good and usually earns good money when you have the battery power to use it.
However, I soon found that suns does not allow access to their systems for Amber to manage the battery. I had to develop something myself that would unload the battery in the morning if the prices rise and request the day on which the prices are low, only negative to relieve relief at night when the prices rise again.
This prize variation is called a solar dent curve, where the morning is the tail of the duck and the evening summit is the head of the duck. (If only the stock market were so predictable, we would all be rich).
I used Home Assistant for a few years to manage Smart -Home devices, and found that the sun -battery, although it was blocked by the provider of third -party providers, and that is blocked by the external access, by the owner to the commands of the RESTFOFFOR use program (API) for local control.
So I build a system to control the battery, but it wasn't very good. I lost in the hundreds of money with the first monthly bill. Then I discovered an open source add-on to Home Assistant called Emhass, which uses an extended control method for calculating plans to manage systems.
I eat in 24-hour forecasts of solar energy (from SOLCAST.com), the supply tariff, the feed tariff (both from amber) and the house consumption and tell how long I load the car and let the pool pump run (and all other exposed loads that I want to charge with the management of the automobile).
I make this calculation every 60 seconds and send commands to all of these devices via the Home Assistant Managed Smart Switched and via the API of the device. All sing together with the price of electricity and available solar.
Here is an example of a 24 -hour -forecast:
24 hours of plan
Battery loading plan and prediction of tariffs.
So far, I haven't cost me electricity in the past two years, although I now mainly top up the car at home. There are a few months and some are below, but always on a loan (so far).
One of the most important things I have learned is not so much the entire computer programming and home automation, but the importance of the load shift and the loads that shift and when.
I also vice versa from gas heating to Lircon, so that's another 500 US dollars a year. I still have hot water immediately and cook top, so next is the list of things to do.
