Solar power system

Photovoltaic System - A photovoltaic system (PV system) uses solar panels to convert sunlight directly into electricity. It is one of the most effective ways to sustainably reduce a property’s energy consumption, lower ongoing operating costs, and increase the building’s market value at the same time.

How does a photovoltaic system work?

The solar modules of a PV system consist of solar cells - typically made of crystalline silicon - that convert incident sunlight into direct current through the photovoltaic effect. An inverter converts this direct current into grid-compatible alternating current, which can be used in the household, temporarily stored in a battery storage system, or fed into the public power grid.

The output of a PV system is specified in kilowatt peak (kWp) and describes the maximum output under standardized test conditions. For a typical single-family home, a system with 8 to 12 kWp is common, generating between 8,000 and 12,000 kilowatt-hours of electricity per year, depending on location, roof pitch, and orientation. In southern Germany, average solar radiation is around 1,100 to 1,200 kWh per kWp per year-a good figure by European standards.

The investment costs for a turnkey rooftop system with 10 kWp currently range from 8,000 to 15,000 euros, depending on module quality, mounting system, and regional installation costs. With an additional battery storage unit (5 to 10 kWh capacity), costs increase by another 4,000 to 8,000 euros. A PV system without storage typically pays for itself in 10 to 15 years-after which the system produces nearly free electricity over its remaining lifespan of 25 to 30 years.

The electricity generated can be used in two ways: Self-consumption-that is, direct use in the household-is particularly economically attractive, as every kilowatt-hour generated on-site replaces the purchase of expensive grid electricity. Surplus electricity is fed into the public grid in accordance with the Renewable Energy Sources Act (EEG) and compensated with a fixed feed-in tariff over 20 years. Since 2023, the operation of PV systems up to 30 kWp on single-family homes has been exempt from income tax-a significant bureaucratic and financial advantage over previous regulations.

Combination with a Heat Pump and Storage

The most economically and ecologically sensible use of a PV system is in combination with a heat pump and a battery storage system. The heat pump uses the self-generated solar power for heating and hot water, while the storage system bridges periods without sunlight. This combination increases the self-consumption rate from a typical 30% (without storage) to 60-80%-and drastically reduces dependence on rising electricity prices.

Some federal states and municipalities have introduced a solar mandate for new buildings or extensive roof renovations. Even though Bavaria currently has no statewide solar mandate, installing a PV system on new buildings is almost always recommended from an economic standpoint. Studies also show that properties with PV systems can command a 3 to 6% premium when sold.

Practical Tip for Homeowners in Nuremberg and Franconia

With an average of around 1,700 hours of sunshine per year, the Nuremberg metropolitan region offers excellent conditions for the cost-effective operation of a PV system. Neighborhoods with predominantly single- and two-family homes, such as Erlenstegen, Mögeldorf, Eibach, or Altenfurt, are particularly well-suited for rooftop systems.

Before installation, owners should have the roof structure inspected, assess the orientation and shading, and inquire about local incentive programs. The City of Nuremberg offers an initial assessment via its solar potential cadastre to determine whether a property’s roof is suitable for a PV system. For historic buildings, special requirements apply that must be clarified in advance with the local historic preservation authority. We are happy to advise you on how a PV system affects property value.

Frequently Asked Questions

Do I need a building permit for a photovoltaic system?

In Bavaria, rooftop photovoltaic systems on residential and commercial buildings are generally exempt from permitting requirements. An exception applies to listed buildings and buildings in areas with special design regulations-in these cases, a permit or coordination with the historic preservation authority is required. Ground-mounted PV systems are generally subject to building regulations and require a building permit as well as a zoning plan.

How long does a photovoltaic system last?

Modern solar modules have a technical lifespan of 25 to 35 years. Most manufacturers offer a 25-year performance warranty, during which the modules will still deliver at least 80% of their rated output. The inverter has a shorter lifespan of 10 to 15 years and typically needs to be replaced once during the system’s operational life-costs for this range from 1,500 to 3,000 euros.

Is a PV system worth it even without battery storage?

Yes, a PV system makes economic sense even without storage. Without storage, the self-consumption rate is around 25 to 35%-the rest is fed into the grid and compensated. The payback period is even faster without storage, as the investment costs are lower. Storage is particularly worthwhile if the household consumes little electricity during the day and the self-consumption rate can be significantly increased through the storage system.

Tenant Electricity: PV Systems in Multi-Family Buildings

In multi-family buildings, the direct self-consumption of solar power by the owner’s unit is usually only a small portion of the total potential. The tenant electricity model is more economically attractive: The electricity from the PV system is supplied directly to the building’s tenants, who thus pay less than they would for grid-purchased electricity. The EEG supports tenant electricity projects with a separate subsidy. The administrative burden is higher than for a simple self-consumption system-individual meters, a supply and billing platform, and registration with the grid operator are required. In Nuremberg, several property managers and homeowners’ associations have begun implementing tenant electricity projects. N-ERGIE offers consulting services and, in some cases, also takes over operations.

For landlords, the economic benefit is that the PV system generates additional income through the tenant electricity margin, the building’s value increases, and the apartments’ market appeal improves-an argument that is becoming increasingly relevant for new leases in Nuremberg, as energy-conscious tenants actively seek apartments with green infrastructure.

How does a PV system affect property value when selling?

A functioning and documented PV system can positively influence property value. Appraisers are increasingly considering it a value-adding factor, especially if there is a current feed-in agreement with guaranteed compensation or if a self-consumption system measurably reduces operating costs. Buyers’ awareness of energy costs is rising significantly-experience shows that a property with a PV system and low energy consumption commands a premium of 3 to 8% over comparable properties without these features in Nuremberg neighborhoods with single-family homes. We recommend professionally documenting the system at the time of sale: performance certificates, maintenance logs, feed-in statements, and subsidy notifications increase the property’s appeal to buyers and make the value contribution transparent.

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