ᐅ Assistance with Solar Panel Decision-Making

I can only comment on the Fronius inverter – it has been running smoothly for 4 years now without any issues. Even during the power outage last Monday, it reliably did its job and kept the house – including the heat pump – fully powered. It was quite eerie, though, when everything outside was dark and our neighbor suddenly knocked on our door because she saw light inside.

I cannot say much about the system size – for example, we only had space for 3.2 kWp.

Regarding the use of a battery, I can only speak from personal experience: I would never install a system without one again. Sure, efficiency and costs come up in the discussion. But the security it provides in an emergency is worth every penny to me. I’ve also clearly remembered the reaction of another neighbor who, the following day, admitted sheepishly that it was a foolish decision not to install a battery and instead opt for better equipment in their new family car.

Therefore, I also recommend installing an off-grid controller.

Jesse Custer schrieb:

To me, the peace of mind it provides in an emergency is worth every penny.

If it matters: Not every energy storage system can do this, and the solutions vary between backup power (a working outlet on the device, for example, to run a chest freezer) and emergency power (supplying the entire household from the battery, where the system’s "black start capability" is crucial). Since many people have little to no understanding of energy systems, these setups are often sold unsuitable for their intended use. Few realize that in emergency power mode, the discharge capacity determines which appliances can run and which cannot. Many also don’t know how long the system can sustain this. Furthermore, only a limited number of systems recharge the battery from solar panels during a power outage, and in winter, the battery must be managed to avoid being empty when an outage occurs. I can hardly think of a topic that generates more unrealistic expectations.

Currently, there is a political debate about whether electricity producers should be charged a fee as a grid usage charge. This would affect everyone who feeds electricity into the grid. It is still unclear to what extent the authorities will agree to this and from which system size or feed-in amount this would apply. However, based on the discussions, I would actually consider investing in an oversized battery storage system—provided it can be realized cost-effectively.

Evolith schrieb:

If you listen to the discussions, I would actually recommend opting for an oversized storage system—provided it can be implemented at a reasonable cost.

These discussions are very investor-friendly again.
Since the last change in February, photovoltaic systems can be shut off during feed-in surplus periods, which means that in the worst case, self-consumed electricity is drawn back from the grid. During the remaining times, the remuneration for fed-in energy is also charged with a grid fee.
Conventional power plants, on the other hand, remain exempt from this.

Alternatively, the self-consumer faces higher fixed fees. So, you end up with double costs due to an oversized storage system and higher basic charges.

Investing is really enjoyable when the framework conditions change every month.

Or you can simply add an AC battery storage system (e.g., Zendure, Anker, etc.) and install it yourself. There are slightly higher conversion losses (about 20 percent) and only 800W output allowed, but the installation costs are just a fraction... it should pay off quickly.

Jesse Custer schrieb:

To me, the security gained in an emergency situation is worth every penny.

I’m not exactly young anymore either, but I can’t recall a power outage lasting longer than 5 minutes.

Jesse Custer schrieb:

instead opting for better features in the new family car,

For me, the features I can use 24/7/365—and actually do—are worth every penny.

The world is just that different.