ᐅ Should You Install a Photovoltaic Battery Storage System or Not?

Zubi123 schrieb:

Most of your electricity consumption does not occur when the photovoltaic system produces the most power, but mainly during the off-peak hours (6–9 a.m. and 4–10 p.m.).
The larger the system, the more electricity you will generate during these off-peak hours. Therefore, you can use your own power during these times.
With the current system costs of about 1,000 euros per kWp, this is economically viable even with a feed-in tariff of 7 cents (return on equity approximately 2.5–3%).
The saved self-consumption is basically a bonus and increases the overall return accordingly.

That’s why it’s best to cover as many orientations as possible with photovoltaic panels! Usually, up to about 25° east or west of south, even the north side is worthwhile (depending on €/kWp installation costs, calculate it yourself and don’t rely on solar installers!).

superzapp schrieb:

That’s why it’s best to cover as many roof orientations as possible with photovoltaic panels! Usually, the north side is worthwhile up to about 25° north of east (depending on the €/kWp installation costs—calculate yourself, don’t just trust the solar installers!)

The idea that the north side is profitable is pure “propaganda” from the energy transition lobby, just like the claim that shaded photovoltaic systems are productive. If you calculate the yield for a purely north-facing system using PVGIS, you’ll think twice about investing the same amount for the north as for the south.

In my opinion, there is only one economically sensible reason to cover the north side—and that is if you are trained and capable of installing the entire system yourself.

I also considered covering the north side, but common sense won out. Spending €9,000 for the north, which delivers one third less than the south in summer, and then very little to almost nothing during autumn, winter, and spring—no way...

...I just checked again, and in the north, the annual yield is exactly 35% lower than in the south.

Zaba12 schrieb:

The idea that the north side is profitable is pure “propaganda” from the energy transition lobby, just like the claim that shaded photovoltaic systems are productive. If you calculate the yield of a purely north-facing system using PVGiS, you would think twice before spending as much money on the north side as on the south side.

In my opinion, there is only one economically reasonable reason to install panels on the north side, and that is if you are qualified and capable of installing the entire system yourself.

I considered installing on the north side myself, but common sense prevailed. Spending €9,000 (around $9,600) for a north side that delivers one-third less than the south side in summer—and then even less or almost nothing comes in during autumn, winter, and spring—no way...

I don’t quite understand the statement about one-third in summer/autumn and winter.
Just take the total annual yield.

If the total yield (kWh per installed kWp) is one-third lower, then you just need to calculate that the north side would have to cost only two-thirds as much for the same profitability.
This often works out. For example, a 10 kWp system costs about €1,300 ($1,400) per kWp, while a 20 kWp system might only cost €1,000 ($1,100) per kWp.
This is due to “volume discount,” meaning savings from combining cables, transport, scaffolding, etc.

As @superzapp said, it depends on the cost per kWp and the actual roof pitch and orientation.

RotorMotor schrieb:

I don’t quite understand the 1/3 summer/autumn and winter statement. Just take the total yield for one year.

If the total yield (kWh per installed kWp) is 1/3 lower, you just need to calculate that the north side must only cost 2/3 as much for the same profitability. Often, this works out. For example, with a 10 kWp system, the cost per kWp might be €1300 (about $1400), and for 20 kWp it drops to €1000 (about $1100) due to volume discounts—combining cables, travel, scaffolding, etc.

As @superzapp said, it depends on the cost per kWp and the actual roof pitch and orientation.

Uh, sorry, but why should the price be €1300 (about $1400) per kWp? Back in 2018, I already got an offer including installation for €1130 (about $1200) per kWp. My solar installer would have thought I was crazy if I expected to pay only €735 (about $810) per kWp for a north-facing system just because the yield is 35% lower, simply by doubling the system size from 8.68 kWp to 17.36 kWp. But I don’t want to be a smart aleck. If someone actually pays 35% less for a north-facing array, then sure, that can be done.

Although we are moving quite far away from the topic of storage, most of that has actually already been said. Economically and especially environmentally, it’s not really a good idea.

Regarding the north side: as mentioned, you really have to calculate it specifically. My numbers were just an example. When you look on the internet and in some other forums, I don’t think they are bad or wrong. Perhaps your numbers are net figures?

However, I never said that the north side is cheaper just because it faces north, but rather as a “volume discount through synergy effects.” I don’t think a 30% discount is unreasonable when you consider how cheap photovoltaic modules are to purchase. Additionally, you could factor in the effect that the 60/70% capping limit for north-facing installations benefits the south side.

From an environmental perspective, photovoltaic systems pay off after about 5 years. On the north side, this would take around 7 years, which I still consider quite good!

We will probably have a 45-degree roof, which corresponds to a disadvantage of more than 50% for the north side; however, in that case, you can realistically only do self-installation.