ᐅ Consultation for photovoltaic system

teh_M schrieb:

We have a consumption of 3900 kWh, of which 975 kWh come from the grid.

Battery BYD 5.2 kWh: 1510 kWh charged, 1174 kWh discharged. 290 full cycles. Efficiency 78%.
Well, the inverter is incorrectly sized, my mistake (5 kW instead of 3.2 kW).
8600 kWh yield from a 10 kWp south-southwest system on a flat roof (5°).

If I only consider the discharge energy, that is 1174 kWh * 0.285 cents per kWh = €330 savings.
The loss of 1510 kWh * 0.10 cents per kWh = €151 feed-in tariff (+ standby consumption when the battery is not charged) opposes that.
I don’t see how I could justify the investment of €5300.

The storage was free by a lucky coincidence. Otherwise, it would never have paid off.

Edit: If I had invested the €5300 gross in additional panels, that would equate to an increase of 4 kWp, which at 860 kWh per kWp/year would be about €344. Definitely a better investment.

You built a very nice photovoltaic system. You use just under 1000 kWh per year from the grid. The savings amount to 3000 kWh.
It doesn’t get much better. That’s exactly my goal. And this example clearly shows that it can be achieved.

I don't do this stuff without reason. But looking at Baerbock, I don’t expect anything good. Nowadays, you’re almost called a loser if you have bought your electricity for years from a so-called cheap provider.

But let’s wait a few more months to see how the battery calculation turns out. With maybe 45 or 50 cents per kWh grid electricity price.

It’s like with a Proxon air heater. When you get drafts, it gets cold—even with warm air. Then you don’t even have a chimney in a costly built Okal house and have to heat very expensively with radiators. I’m curious what will happen if it’s minus 25 degrees Celsius (−13°F) for four weeks and the heat pumps have to run at full capacity. It will be interesting.

And looking around?
Of 50 French nuclear power plants, 16 are currently out of service. The German nuclear plants have been shut down. Plus coal power plants.
Nord Stream II is not wanted, gas storage is empty. Instead of Russian gas via pipeline, they want liquefied natural gas from the USA.
At the same time, electricity consumption is increasing massively: electric vehicles, infrastructure, heat generation, and so on.

I honestly don’t know how this is going to work out.

You can find information about this, among other sources, at the Fraunhofer Institute.

So, you really mix up all topics freely and polemically, @Durran.

Baerbock has absolutely nothing to do with the current electricity prices, providers, or anything else.

Air-source heat pumps do not cause any "cold drafts" if properly designed. Nobody really needs a chimney in a new build with a correctly planned heat pump if they want to live environmentally consciously.

At -25°C (−13°F) over four weeks, even a normal wood supply for today’s single-family houses is quickly depleted, and then they can use radiators for additional heating—they just don’t have them at home right now.

That 16 nuclear power plants are out of service and that France currently has extremely high electricity prices (usually higher than in Germany on the market) only demonstrates that it is the right decision to move away from nuclear power in the long term.

No one claimed that Germany’s one-sided dependence on Russian gas was a good idea. We can thank Gerhard and then 16 years of CDU leadership for that. To connect back to the beginning: this also has nothing to do with Baerbock. You can think what you want of her, but she hasn’t ruined anything so far. That was a mixed bag of CDU, FDP, SPD, and at some point even the Greens as junior partner during Schröder’s time.

While I was writing my post, I briefly visited Twitter. That’s when I noticed this picture of her after her meeting with Lavrov. It must have really taken a toll on her. I haven’t seen the pretty lady looking so swollen and worn out before.

That inspired me to stray from the original topic.

Fuchur schrieb:

In my opinion, the discharge amount—that is, losses already deducted. That’s also how I calculated my value.

Actually, you should consider the energy on the DC side when charging the battery. Simply put, the rectified current flowing into the battery (*voltage*time). The losses in the discharge amount are partially converted into heat by the inverter. This is due to the low base load overnight, the large inverter, and the unfavorable efficiency.
Additionally, there is standby consumption and self-discharge(?), which must have been stored as energy in the battery beforehand. So the truth is probably somewhere between the two amounts?!

Durran schrieb:

You have built a nice photovoltaic system. You consume just under 1000 kWh per year from the grid. The savings amount to 3000 kWh.
It doesn’t get much better than that.

Well, it could actually be better. The system was installed by ourselves on our garage. I should have fully equipped the house with panels while the scaffolding was still up, that is, east + west. That would increase self-consumption, especially in the mornings and evenings, during the transitional seasons and winter. I would have preferred that much more than the battery storage….

Durran schrieb:

I've never seen the pretty one so swollen and worn out.

Some media reported that she caught conjunctivitis.