ᐅ Comparison of Photovoltaic System Quotes

Hello,

please share your assessment of the quotes. The offers are fairly easy to compare on paper, but I have no experience regarding the materials, optimal orientation, etc.

I will attach one quote in this post and the other in the post directly below.

The system is planned for a household of 2 people (up to 4 later) with an air-to-water heat pump, underfloor heating, and decentralized ventilation with heat recovery. The heat pump should also provide domestic hot water. The goal is to use as much self-generated energy as possible. Due to the orientation, an east-west setup is planned.
Please note that we received offers for systems of different sizes. The larger system is slightly cheaper per kWh (1220.89 compared to 1363.54). According to online research, the smaller system appears to be very well known and mature. I found less information about the larger one. However, the provider of the larger system is significantly bigger than the other. Below is the larger system.

Here is the small system.
My general questions:

- Are both systems suitable for northwest orientation? 45-degree roof pitch.
- What should be considered regarding the small gable related to shading? Different arrangement?
- What system size is reasonable?
- Is it useful to feed electricity back into the grid for payback?

1. You can easily get 15 kWp or more on that. Do it! For example, the south-facing gable roofs. Only north-facing gables are unsuitable. Areas north of the gable at the bottom might be borderline, but that can be simulated. Leaving some space on the side south of the gables doesn’t make much sense, except maybe due to specific string lengths.

2. For effective shading management, there are several options. The inverter must be capable of handling this, and it depends on the module string configuration to work well. If it’s not feasible with a conventional setup, then SolarEdge is an option.

3. A 70% hard power limitation seems sufficient from my gut feeling.

Try planning the roof yourself to cover it as fully as possible, then determine what makes sense regarding shading management and string lengths.

There are also forums dedicated exclusively to photovoltaics.

Yes, of course, feed in the electricity. I find both prices acceptable.

boxandroof schrieb:

1. You can fit 15 kWp or more on that. Go for it! For example, the gable ends facing south. Only north-facing gable ends are unsuitable. Below the gable ends on the north side might be borderline, but that can be simulated. Leaving some space on the south side of the gable doesn’t make much sense, except possibly due to certain string lengths.

Thanks for the input. I forgot to mention that the lower offer also includes east-west oriented modules. But you’re absolutely right. There’s definitely potential for more. I’ll take another look.

Ask your question in the photovoltaic forum. You will get much more qualified answers there – this forum is more about "stones." I find the price relatively high for the offered modules/system.