ᐅ Photovoltaic Systems: Advantages, Disadvantages, Experiences, and Is It Worthwhile?

blackm88 schrieb:
There are two types: a maximum of 70% or participation in feed-in management: 100%-60%-30%-0% ...
With a purely south-facing roof, that is the question. In my opinion, a battery in the basement is uneconomical.

Even participation in feed-in management brings relatively little benefit. The costs for the ripple control receiver and the annual fees are usually higher than the compensation for the typically additionally fed-in energy.

That’s why Fronius inverters are very popular. With a simple meter costing about 50€ (around $55), a gradual 70% can be implemented. This makes sense slowly over the payback period.

blackm88 schrieb:
Honest question to all of you ... is it still really worth it compared to 10 years ago?

Kind of. Feed-in tariffs have decreased, but photovoltaic modules have become significantly cheaper. Added to this are heat pumps and electric cars as useful storage and self-consumption solutions, especially if the car is parked at the house during the day.

The highest profit margin is still with the photovoltaic installer, who pays €150 (about $165) per unit from the Chinese supplier and installs it on your roof here for €1000 (roughly $1100).

Mottenhausen schrieb:
Not exactly. The feed-in tariff is lower, but photovoltaic modules have become significantly cheaper. Heat pumps and electric vehicles have also been added as practical storage and self-consumption solutions, especially if the car is parked at the house during the day.

I compared the return on investment from a recent system with that of my father-in-law from the peak subsidy period. For about the same amount of money, he got a much smaller system back then. However, his subsidies were much higher. In the end, his return is slightly better than mine. It is still worthwhile for me as well.

Mottenhausen schrieb:
The highest profit margin is still for the solar installer, who pays €150 per unit from the Chinese wholesaler and installs it on your roof for €1000.

What do you mean by a “unit”? A module? Unfortunately, margins aren’t that high...

kwp

goes down to 100€ / kwp

plus all the installation stuff, control electronics, inverters, etc., of course

I’m bringing this topic back up in hopes of getting some questions answered:

The cost-effectiveness of photovoltaic systems is generally low in winter (where heating and hot water demand is highest) and this lowers the overall average. But how does it look in summer, for example? Let’s say you include an air-to-water heat pump or a ground-source heat pump in the calculation and add a cooling module for the summer. Wouldn’t that significantly increase the yield from the photovoltaic panels for cooling purposes?

Regarding batteries/storage, I have come across mixed opinions so far. How is this handled in a single-family home, especially when aiming for KfW 40+ certification?

There seems to be a lot of confusion here.
You cannot generate higher returns simply by increasing self-consumption. Intentionally creating self-consumption just for the sake of using the energy is the opposite of economical.
A battery storage system is never economical; you can calculate that within three minutes.
A photovoltaic system is only economically viable due to feed-in tariffs; optimizing self-consumption improves economic efficiency.