Photovoltaic system: self-consumption rate with battery and further questions

Hi,

if they are LiFePOs, it is of course already significantly better.
The Dreamliner had and has LiCoO2 batteries, that's a different league.
They never really found out why exactly those things caught fire, or at least never published the reason. In the reports that were available online, there was something mentioned about "Voltage drop" but no one knew why.
The workaround there is to encapsulate the batteries fireproof and at the same time channel the fire gases outside through a duct.
I honestly find it a bit funny that packages with toys containing Lipo batteries are usually no longer transported by plane nowadays (too high fire risk), but at the same time they install a huge battery in the airplane.

If the inverter plus battery is constantly connected to the network, I would keep a very close eye on open ports, passwords, etc. If they are not significantly smarter than many other companies, there will be a standard login with a standard password on it. If that is not changed, it is basically only a matter of time before some script kiddies notice and find it incredibly funny to kill the batteries for those people. With LiFe at least it won't blow up in your face, but damaging it by deep discharge is already annoying enough.

Best regards,

Andreas

If the inverter plus battery is constantly connected to the network, I would keep a very close eye on open ports, passwords, etc. If they are not significantly smarter than many other companies, there is a standard login with a standard password on it. If that is not changed, it is basically only a matter of time until some script kiddies find out and think it’s insanely funny to kill people’s batteries. With LiFe, at least it won’t blow up in your face, but damaging it through deep discharge is already annoying exactly

Absolutely right. Your objections show that you are enormously constructive and really know your stuff. I believe that is exactly what sets this forum apart from all others of its kind in a clearly positive way.

I have already addressed the point mentioned here. According to my information so far, it is solvable. Regarding port releases and so on, I will definitely devote some of my time to this topic before the system goes into monitoring (it must do so, that is part of the contract).

Once again, a heartfelt thank you to you for your constructiveness.

Best regards Thorsten

PS: ...who hopes that my questions in the initial post are not forgotten....I know, there aren’t many systems of this kind yet.....it would be great if photovoltaic system owners would get in touch.

PS2: The thing with the Dreamliner... totally exciting. Here again you are right.

PS3: Time's up... lol. Due to the monitoring: If the battery threatens to enter a discharge state that is not good, the entire system is shut down via RC. This generally applies to all parameters of the system, which are monitored in real-time; if limits are exceeded, the red switch turns on.

If, of course, a Man-in-the-Middle or similar blocks something here: everything breaks down. Script kiddies are clever here.

So again: Great contribution from you, one (I) has to devote more attention to the topic (even more than before).

My questions:
1. Who of you already has a photovoltaic system with buffer battery and has information about your individual self-consumption rate?
2. What experiences do you have with east-west orientation of such systems?
3. What means and methods do you use to further increase the self-consumption rate? Personally, I have some "nonsensical" (?) ideas in mind, such as possibly simply waiting for a day with good weather before turning on the washing machine and the like. Does such behavior bring a noticeable result?
4. How satisfied are you overall with your decision in favor of a photovoltaic system?
5. My house requires less energy than the energy consumption values indicated in the current energy certificate predict. That is pleasing, but otherwise worthless.
Nevertheless: If you sum up the necessary electrical auxiliary energies (heating, circulation pumps, solar pump of the existing thermal solar system, controlled residential ventilation, ...), a noticeable amount accumulates over the year. With the current primary energy factor of electricity of 2.4 anyway, but also with the coming year (primary energy factor electricity = 1.8).
In connection with the solar system, a better value would result in a recalculation of the energy certificate, because the auxiliary energies partly come from the photovoltaic system/battery? Also, the house generally produces a larger share of energy from renewable sources due to the photovoltaic system?
What do you think: Is it sensible and worthwhile to recalculate the existing certificate after installation?

Hello Thorsten,

I will address your questions - as far as I can answer them.

We have had a photovoltaic system with 5.36 kWp south-south/east orientation without a battery running since 09/2014.
Therefore, my information - logically - only refers to this.
In addition, we use our electricity yield ONLY for household electricity. The brine heat pump runs on the cheaper heat pump electricity tariff. Photovoltaic may not be coupled with that.

Our self-consumption over the year is about 20%.
However, I must say that we are generally relatively economical in electricity consumption. In the old apartment, our household electricity demand was about 2,700 kWh, with 2 adults and two small children. So the washing machine was used quite often. Appliances such as dryer, refrigerator, stove, cooktops, dishwasher were replaced by modern devices when we moved in. Only the washing machine and freezer (as well as various small devices) remained old.

There is - naturally - a difference in self-consumption between summer and the darker seasons. In July our self-consumption was about 19%. In February about 30%.

Regarding 3. Certain measures do bring some benefit in my opinion.
- Running the washing machine and especially the dryer during high production is sensible.
- Programming the dishwasher to start, for example, at 12:00 also makes sense (as long as the sun shines between 12:00 and 14:00).
- Other measures - well: those who like to cook in advance and reheat in the evening also save, but possibly at the cost of taste and quality. Besides, who is always at home during the day?
Discipline is important here! Running the washing machine between 10:00 and 16:00 and not starting it only in the evening or in the morning after getting up. Also - anyone with small children will know: laundry must be done when it accumulates. Collecting it is only possible to a limited extent.

Someone who lets the heat pump be supported by photovoltaic will be able to increase their self-consumption quota. However, one should not have too high expectations in the cold season. November is almost over, and my system produced just 160 kWh this month. Of this, nearly 60 kWh was self-consumed this month. January and February 2015 looked even gloomier.

A battery definitely helps to increase the self-consumption quota. Whether this is financially worthwhile, I find hard to assess. Currently, several providers are pushing onto the market (Tesla), which will probably shake things up significantly.
To what extent the SMA Smart Home technology really helps is questionable. Also - because Smart Home doesn’t work with every programmable device.

4. We are satisfied with our photovoltaic system and would do it again - however, the feed-in tariff has decreased further since 08/2014.

5. Our general contractor (whose employees are also qualified to issue the energy certificate) said that a photovoltaic system does not have a very large impact on the energy certificate rating. To what extent this is true, ...? The effects could be greater if the heat pump is supported by photovoltaics. Could be!

SO - I’m going to save energy now and turn off the laptop ;). Good night.

Dear f-pNo! Thank you very much for the interesting information. Have a nice Sunday. Best regards, Thorsten

:confused:. Meanwhile, there are so many solar systems.

And so far, only one family is sharing their experiences here with me.

:rolleyes:....Are all the others just sitting in front of their inverters, completely frozen with excitement because of the values???

Well....in a year I hopefully have my own values. I'll type them in here then. Smile.