Bauhaus concrete villa with core insulation - experiences

An east/west system is definitely the right option if no storage is available or planned in the near future. This way, you can use self-generated electricity directly from early morning until evening. On the other hand, if you have a (quite large for a normal household) storage system like , it makes sense, especially in the winter months, to orient towards the south in order to ideally fully charge it by the afternoon. With a ratio of photovoltaic system to storage of 1 to 1, this is still difficult to achieve from November to January with an east/west system (except perhaps in Freiburg). Basically, however, a photovoltaic system is always better than none, because it’s fun.

With more powerful modules, we could have added a bit more. We have 310 watt modules.

Do you (or a reader) maybe have some info on this? We are currently planning our system, and two providers offered me 310 and 315 watt modules respectively. But no one explains calmly and understandably why 310 or 315 would be such a cardinal mistake. Is it like with Tim Taylor, the DIY king, simply more power whenever possible?

In photovoltaic systems, there is a 70% regulation or active power reduction.
This can be implemented in two ways.
Usually, the inverter is already sized smaller than the theoretical power of the modules and is set in the inverter.
The power reduction of the system refers to the feed-in.

70% hard means that this is set in the inverter. Simply put, for example, you have a 10 kWp system. If you do not consume any electricity yourself and the system delivers 10 kW (which it never really does), your inverter limits to 70%. So only 7 kW feed into the grid. If you consume 7 kW yourself, there is no feed-in. Only 70% is ever reached regardless of the distribution.

70% soft or dynamic means that your own consumption is taken into account. This is possible through an additional meter and a corresponding inverter.
If you do not consume any electricity yourself and the system delivers 10 kW (which it never really does), your inverter limits. So only 7 kW feed into the grid. If you consume 7 kW yourself, there are still 3 kW feed-in. In other words, you can use the full power as soon as your own consumption is > 30% of the total power.
It is somewhat more complex in terms of investment and installation.

Of course, there are differences even among 310 watt panels. Therefore, no general statement is possible. If you have a space problem, more powerful modules make sense. For us, it didn’t matter. We still reach almost 10 kWp. More powerful modules often have newer technology, for example, they still deliver more power under strong heating (direct sun in summer) and do not drop off as much. The technology is also somewhat changed.

We have Luxor ECO LINE FULL BLACK LX-310. Originally, we wanted the AC-310M. However, these were not available. Since the Corona drama had already started in Asia, we switched to the available modules. Luxor offers a German warranty since there is a German company behind it. Of course, you can also push technological limits and use 370 watt panels with the latest technology. This panel then costs twice as much as our 310 watt module. Ultimately, it depends on your space, how much you want to invest, whether you design the system for maximum return, etc.

We just wanted a good and sensible system. Economically, we certainly did not get the maximum out of it.

We are on a similar latitude as Freiburg. It could work.

Alright, thanks for the input. In East-West we should actually get about 9kwp on it, so I didn't quite understand the criticism, especially since it wasn't explained why... and for us, the acquisition costs do play a role, unfortunately

Costs also play a role for us. Even if it sometimes may not seem that way from the outside. Otherwise, I probably would have chosen "better" modules or done something differently in other areas. Everyone has to stretch according to their means. Ours might be a bit higher. However, the price fluctuations for this property are also greater. Whether the floor costs 50€ more per m2 makes maybe 6000€ difference for a "normal" house (with 100m2) and about 30,000€ for us (if you assume 500m2)...