ᐅ Balcony Solar System – With or Without Battery Storage? Orientation?

nordanney schrieb:

Yes, typical balcony solar storage units are generally designed and intended for outdoor use.
An IP65 rating and an operating temperature range of at least -10 to +50 degrees Celsius (14°F to 122°F) should be the minimum requirements for any storage unit (some even offer down to -20 degrees Celsius (-4°F) and IP66 – from all brands like Growatt, Anker, Marstek, etc.).

I looked at a Growatt NOAH 2000 online. You are right, it formally meets these conditions.
The price is around 500€ per kWh of storage capacity. Assuming a (randomly chosen) cost advantage of €0.25 per kWh, you would need 2000 cycles to break even. That will probably take a while.

I’m also not entirely sure about the battery storage. Basically, there wouldn’t be anything against buying it later on, right? Well, then you would just have the issue that the direct current would need to be converted to alternating current twice, which leads to higher losses. Or am I missing something?

HubiTrubi40 schrieb:

Okay, then the problem would be that you would have to convert from direct current to alternating current twice, which results in higher losses. Or am I missing something?

With an AC-coupled storage system, you convert AC to DC once to store the energy and DC back to AC to use it again. You can generally assume converter losses of about 4% per direction and storage losses around 2%. That adds up to roughly 10% loss, maybe even 12%. If losses at this scale threaten the system’s cost-effectiveness, then it’s better not to buy it.

HubiTrubi40 schrieb:

Also considering a system on the roof, but I thought I’d start with a balcony solar unit first.

Then a balcony solar unit without storage for now, to reduce some of the base load. Later, install a proper photovoltaic system with storage. Regularly record your meter readings now to better understand your consumption profile. Consider whether a heat pump, electric car, sauna, pool heating, etc., are planned.

A battery storage system is generally more cost-effective for a balcony solar setup than for a large rooftop system, since it likely experiences many more charge and discharge cycles (possibly even within the same day) compared to a large system, and probably does not receive feed-in tariffs.

With my 13 kWh system, I have not had a single day since the end of March where the smallest possible battery for my system was fully discharged. I use only 2-3 kWh overnight on a daily basis. On average, this means not even one full charge cycle every 2-3 days from April to September. During the three winter months, production is low, so you don’t get many cycles then either. I wonder how the 220-250 charge cycles per year from manufacturer calculations are supposed to be achieved. However, reaching that number depends on timing major electricity consumption to coincide with surplus generation. Of course, having a battery is more convenient. On the other hand, if you have a high base load at night, a battery becomes much more worthwhile.

Musketier schrieb:

A battery storage system is much more cost-effective with a balcony solar setup than with a large rooftop installation, since you can expect significantly more charging and discharging cycles (possibly also during the day) than with a large system, and you probably won’t receive feed-in compensation.

Yes, because there is no feed-in compensation, every stored kWh from a balcony system has a higher value.

The number of cycles depends on the usage pattern. Of course, you can try to anticipate future plans and price developments based on the usage profile, but I consider that pure speculation.

There are often misunderstandings, such as the assumption that using an electric vehicle would increase the number of cycles. This only applies if the vehicle is charged in the morning after the battery was already fully charged, then drained, and can be charged again the same day. Our electric car is used by three people and is the preferred vehicle for trips up to 100m (330 feet). To ensure everyone can leave anytime, it is recharged at home whenever someone gets out. This approach is not cost optimized but maximizes spontaneous availability and avoids additional coordination. Since we got the electric car, the cycle count of our home battery has significantly decreased.