How does a balcony power plant with storage work?

First, a brief explanation: What exactly is a balcony power plant with storage?

Balcony power plants with storage are compact photovoltaic systems that allow you to generate and store solar power directly on your own balcony or terrace. The major advantage over traditional balcony power plants lies in the battery storage, which stores the electricity generated during the day and releases it when needed. The storage system holds onto the generated energy and releases it, for example, when the sun isn't shining. This allows you to use your self-generated electricity in the evenings or mornings, increasing your independence from the energy supplier and reducing your electricity costs.

How these mini PV systems work in detail

How does a balcony power plant with storage work? What happens during this process, and how does it unfold in the individual components? We'll explain it all in the following text.

Energy generation: Conversion of sunlight into electricity

Solar modules consist of several solar cells made of semiconductor materials such as silicon. When sunlight hits the solar cells, the photons of light are absorbed. These photons excite the electrons in the semiconductor material, creating an electrical voltage between the different layers of the solar cell.

This process generates direct current (DC) , which is drawn from the solar cells . Since the generated DC current cannot be fed directly into the household electrical grid , it is converted into alternating current (AC) by the inverter , which can then be used by household appliances.

The process within an energy storage system and the release of energy

If the solar panels of a balcony power plant with storage generate more solar energy during the day than is directly consumed, the excess electricity flows into the battery storage. Here's what happens:

Charging process : The direct current from the solar modules is routed to the battery via the inverter. Here, the energy is stored electrochemically.
Storage : The stored electricity remains in the battery until household electricity demand increases. Intelligent energy management can optimize its use.
Discharge : As soon as electricity is needed in the household, the battery releases the stored energy. This happens automatically, as the stored electrical energy is converted into usable alternating current and fed into the household grid.
Household energy supply : The solar power generated is used as a priority to cover your own electricity consumption. For example, base load appliances such as refrigerators, Wi-Fi routers, and lighting are preferentially supplied with stored solar energy, which is then fed from the storage system into your grid.
Grid interaction : If the storage system is full and solar power continues to be generated, excess energy can be fed into the grid. In some cases, this feed-in to the public grid can even lead to a reduction in electricity costs.

Modern energy management systems handle intelligent control by monitoring the battery's charge level and optimizing energy flow. Many of these systems can be controlled via a smartphone app to efficiently regulate electricity consumption and storage utilization. Without storage, unused, surplus electricity would simply be fed into the grid, thus being lost without compensation.

Components of a balcony power plant with storage

Solar modules: Structure and function

Solar modules are a fundamental component of solar power systems, converting incoming sunlight into direct current using solar cells . Highly efficient monocrystalline or polycrystalline modules are used for this purpose. Modern solar modules are optimized to achieve good performance even in diffuse light conditions.

Three angled solar panels from MOECELL, mounted on a balcony railing. Soon at your home too?

Inverter: Conversion of direct current to alternating current

Since household appliances generally require alternating current (AC), the direct current (DC) generated by the solar panels is converted by an inverter. A high-quality inverter ensures efficient conversion and optimizes the self-consumption of the generated energy.

Hoymiles inverter for balcony power plants – compact micro-inverter with connections for solar modules and mains plug, optimized for efficient energy conversion.

Storage unit (battery): Types of storage devices and their properties

The battery storage unit is the heart of a balcony power plant with storage . It ensures that excess solar power is stored and can be used at a later time. There are various battery types that differ in storage capacity, efficiency , and cost :

Lithium-ion batteries : High storage capacity , durable and efficient. Frequently used in PV and solar power systems .
Lead-gel batteries : Cheaper, but heavier and less efficient.
Saltwater batteries : More environmentally friendly, but currently still expensive. They offer a sustainable storage option .

MOE balcony power plant with storage, solar modules mounted on the railing and side, electricity storage on the balcony.

Our recommendation: a balcony power plant with storage from MOE

Modular expansion: Our balcony power plant storage systems and balcony power plants are modularly expandable. Our balcony power plants can be supplemented with additional modules, and our storage system also offers several advantages.

Our storage is:

Easy to integrate: Whether with or without a balcony power plant, MOE can be effortlessly integrated into your household.
Modularly expandable: Flexibly adjust the number of batteries to your needs – one inverter is all you need.
Versatile (Plug Play): Also usable as a plug-and-play storage system for large PV systems to make sensible use of excess electricity.

You're probably wondering now - why MOE?

With MOE, every household can become an active part of the energy transition - and save money in the process.

MOE is a plug-and-play system: simply plug it in and get started immediately.
Developed by a Stuttgart-based start-up – Engineered in Germany with German customer support.
Open software interface: Seamlessly integrates into smart home systems such as Home Assistant.

Use MOE also as a power station:

Charge MOE at low prices via a dynamic electricity tariff.
Use the stored electricity when tariffs are high.
Save up to two-thirds of your electricity costs.

Is investing in such a system worthwhile?

There are several factors that make the investment worthwhile.

Increased self-consumption : Use of the generated solar power also in the evening hours.
Energy independence : Less dependence on rising electricity prices .
Environmental friendliness : Reduction of the CO₂ footprint through solar energy .
Long-term savings : Reduced electricity bills due to lower grid consumption.

An efficiently used MOE system can save up to €552 annually on electricity costs by directly using self-generated solar power . In some regions, there are government subsidy programs for PV systems and storage systems that can further reduce the purchase costs. The amortization period for MOE systems ranges from 4.7 to 5.4 years , depending on the self-consumption rate, energy prices, usage patterns , and local subsidies .

A brief example of cost accounting with MOE:

Graph of an example calculation for annual electricity savings with an MOE storage system

Installation and commissioning

Installation of solar panels: What should be considered?

The installation should take place in a sunny location, ideally facing south, east, or west . A sturdy balcony bracket or facade mounting are suitable options.

System connection: Integration into the existing power grid

The balcony power plant is simply connected to the house's electrical grid via a standard electrical outlet . Different requirements apply depending on the grid operator .

Maintenance and care: Tips for long-lasting operation

Regular cleaning of the solar panels .
Checking the battery and inverter .
Control of power feed-in via smartphone app .

Economic efficiency and environmental aspects

Cost-benefit analysis: Is the purchase worthwhile?

A balcony power plant with storage costs from €1000, depending on output and storage capacity . Up to €3,500 . The savings on electricity costs can mean the purchase pays for itself within a few years. However, it's important to consider the quality; systems that are too cheap may lead to further costs later due to poor quality, and safety aspects should also be carefully considered.

Funding opportunities: Are there any government subsidies available?

In Germany, there are various funding programs for balcony power plants with storage . Furthermore, since 2023 , photovoltaic systems have been exempt from 0% VAT . Check with your local city to see if they offer such funding opportunities.

Contribution to environmental protection: Reduction of the CO₂ footprint

Using solar energy reduces CO₂ emissions , contributing to the energy transition and promoting long-term sustainability . This is also the reason for the various subsidies offered by the government. Work will continue in the future to simplify the process and provide positive incentives for such solar installations.

In summary:

A balcony power plant with storage offers the opportunity to use solar power efficiently and increase your energy independence . The investment pays off through lower electricity costs and better utilization of self-generated solar power – especially in the evenings. It should be viewed as a long-term investment, but one that brings several positive aspects. With relatively little money, you can make a significant contribution to the energy transition and produce green electricity.

Frequently Asked Questions (FAQ)

Can I install a balcony power plant with storage in my rented apartment?

Yes, however, you should first check with the landlord whether installation is permitted.

How large should the storage space be for my household?

This depends on individual electricity needs . In most cases, a 1–2 kWh battery is sufficient for basic needs. Our storage systems offer 2 kWh per unit and are modularly expandable.

What permits are required?

Balcony power plants generally only need to be registered with the market master data register . Registration is required. Additional permits are usually not necessary. However, as a tenant, you should clarify the regulations of your landlord or your rental agreement. Please refer to our article on the legal situation for more information.

Will a balcony power plant with storage work during power outages?

A balcony power plant with storage can function during power outages in certain cases, but there are limitations. Many systems are designed to automatically shut down for safety reasons during a power outage , as they are connected to both the home's electrical system and the public power grid .