Making good use of excess PV power – 6 options compared

Every photovoltaic system produces more electricity on sunny days than the household directly consumes. The crucial question is what to do with this surplus. Depending on the situation, different solutions are worthwhile; this guide presents six of them.

Making good use of excess PV power – from heating elements to electric cars

Those who want to make good use of surplus PV power will have six clear options to choose from in 2026. With the reduced feed-in tariff, self-consumption is significantly more worthwhile than selling to the public grid. Which solution is suitable for which situation depends on system size, heating system, mobility, and budget. This guide presents the six proven options and shows when each is worthwhile. We at PVundSO regularly support households with our electrical engineers during the installation process and have compiled the most important key figures from practical experience. All recommendations are based on current prices and subsidies as of April 2026.

Why using excess PV power is now more worthwhile than feeding it into the grid.

Feed-in tariff versus electricity price 2026

The feed-in tariff under the German Renewable Energy Sources Act (EEG) will be around 7,94 cents per kilowatt-hour for new systems up to 10 kWp in 2026. Electricity purchased from the grid will cost an average of 30 to 40 cents per kilowatt-hour during the same period. Those who consume their own solar power will therefore save roughly four times as much as the feed-in tariff, depending on the tariff. This gap is so significant that the entire logic of system planning has shifted. Today, those building systems size inverters and modules with a view to maximizing self-consumption, rather than maximizing yield.

Why self-consumption is the new key figure

The classic logic of the early PV years has thus been turned on its head. Today, optimizing self-consumption counts more than the amount of electricity fed into the grid. Every additional percentage point of self-consumption reduces the grid electricity bill and noticeably shortens the amortization period of the entire system. This effect is even more pronounced with smaller systems, because the fixed grid feed-in has a proportionally larger impact.

In our installations, we regularly see households increase their self-consumption rate from the typical 30 percent to over 70 percent. The specific strategy depends on the heating system, mobility, and household size. There are six ways to achieve this, which can be used individually or in combination. The order in which they are implemented is worth considering carefully. Some steps are so cost-effective that they take effect immediately, while others only become worthwhile with a certain system size.

Option 1: Direct self-consumption through time control

Manual time control via timer and app

The simplest way to make good use of excess PV power is to shift the operation of large appliances to the sunny midday hours. Washing machines, dishwashers, and dryers then run when the system is operating at peak capacity. This is possible without additional investment and yields immediate results. A quick glance at the daily production curve reveals when appliances are truly worthwhile. The highest energy surplus occurs between 10 a.m. and 16 p.m., especially in summer.

Automation with Home Connect and Smart Plugs

Many modern household appliances with Home Connect functionality or similar interfaces support a solar mode. The device starts automatically when the inverter reports sufficient surplus energy. Alternatively, Wi-Fi sockets (so-called smart plugs) control older devices according to predefined rules. A small energy app makes everyday life easier. It reports available capacity via push notification and automatically starts compatible devices. Many inverter apps already offer this feature.

The investment ranges from zero to 300 euros, depending on whether existing devices are sufficient or new smart plugs are added. The effect is a 5 to 15 percentage point increase in self-consumption. For any PV system, this is the logical first step before larger investments. Especially in combination with a wallbox or an immersion heater, this timer sets the basic rhythm for the entire energy planning in the house.

Option 2: Store excess PV power with battery storage

How much capacity you really need

Battery storage is the classic solution for storing excess PV power and using it in the evening. Typical capacities range from 5 to 15 kilowatt-hours, depending on the system size and consumption. A rule of thumb is 1 kWh of storage per installed kWp of PV system. Storing significantly more capacity than the household can use in the evening is wasting energy. Conversely, undersized systems lose valuable surplus power fed into the grid.

Combination with inverter and emergency power function

A 10-kilowatt-hour storage system will cost between €6.000 and €11.000 in 2026, including a hybrid inverter. Depending on electricity prices, the payback period is 10 to 18 years. The system can also function as an emergency power source if a suitable transfer switch is integrated. A good example from our product range is the Jackery HomePower Ultra 2000 with optional additional batteries and an integrated emergency power outlet. Modern lithium iron phosphate batteries last 15 years or more.

With a battery storage system, the self-consumption rate typically increases from 30 to 60 to 70 percent. In combination with a heat pump and wallbox, even 75 to 85 percent is possible. You can find our entire selection of fixed and mobile energy storage systems in the Energy Storage category . It's important to note that the storage system incurs approximately 5 percent loss with each charging process. Those who can directly use their surplus energy for hot water or to charge their electric vehicle avoid this conversion loss.

Option 3: Heat hot water with an immersion heater

How a PV heating element works

An electric heating element in the hot water storage tank converts excess PV power directly into heat. An energy manager monitors the solar yield and activates the heating element as soon as sufficient surplus energy is available. This way, otherwise unused electricity ends up in the domestic hot water or buffer storage tank. The heating element itself is a robust immersion heater made of stainless steel or brass, which is screwed into the storage tank via a 1,5-inch socket. The power manager modulates its output continuously between zero and maximum.

Costs and amortization in everyday life

Depending on the system, the investment ranges from €300 to €2.000, including controls and installation. With an annual boost in self-consumption of 500 to 1.500 kilowatt-hours, the immersion heater pays for itself in 4 to 10 years. The effect is particularly noticeable if hot water is currently supplied by gas or oil. Those who already own a heat pump should carefully examine the cost-effectiveness, as heat pumps operate with a COP of 3 to 4, making them significantly more efficient. For households relying solely on gas or oil heating, however, the immersion heater remains one of the quickest solutions.

For a comprehensive introduction to selecting storage systems and heating elements, please refer to our guide " Utilizing PV Surplus with Heating Elements ." We recommend the my-PV AC-THOR Power Manager as the central control unit for converting surplus energy , which provides stepless control of external heating elements. This solution can be implemented within just a few days, especially in existing buildings with gas or oil heating systems. Electricians and plumbers work closely together on the project.

Option 4: Operate heat pump with excess control

When the heat pump best absorbs the excess heat

A heat pump is the second largest electricity consumer in a household after an electric car. This makes it the ideal consumer of surplus solar power. An energy manager signals available solar power to the heat pump, whereupon it increases the charging of the heating system or buffer storage tank. The electronic interface of the heat pump is crucial. Modern models offer SG-Ready control or a digital input for the energy manager. Without this interface, surplus energy utilization remains limited to rudimentary on/off logic.

Combination with buffer storage

The key factor lies in the COP (Coefficient of Performance) between 3 and 4. Every kilowatt-hour of solar power is converted into 3 to 4 kilowatt-hours of heat. This makes the heat pump more efficient than any immersion heater and makes solar power valuable even in winter. Combined with a 500-liter buffer tank, it operates with exceptional flexibility. It charges the buffer tank in advance when there is excess solar power, shifting consumption away from the evening hours when grid power would otherwise be used.

Depending on the model and output, the investment ranges from €18.000 to €30.000 before subsidies. BAFA and KfW reduce the costs by 30 to 50 percent. As electrical engineers, we oversee the hydraulic and electrical integration into the existing PV system, for example, with the Bosch air-to-water heat pump . Our team can also handle the registration with the grid operator upon request.

 

Option 5: Charging an electric car with excess solar power

Which wallbox supports PV surplus charging?

For electric car owners, surplus solar power is by far the cheapest electricity provider. A wallbox with a surplus charging function charges the vehicle exclusively with the solar power that is currently available. Instead of 37 cents at a public charging station, the household only pays 5 to 7 cents per kilowatt-hour for the electricity. Calculated over a year, this results in noticeable savings compared to any other electricity source in the household, assuming an average annual mileage.

Typical annual savings

A wallbox with dynamic load control and connection to the energy management system is required. This function is available on numerous modern devices starting at around €800. A separate load profile meter or a compatible inverter provides the control data. Some manufacturers also offer bidirectional wallboxes that can use the vehicle's battery as an additional household storage system. This technology will not yet be widely available in 2026.

A family driving 15.000 kilometers annually typically saves €600 to €900 by using surplus solar power compared to charging solely from the grid. This increases the self-consumption rate by 10 to 20 percentage points. The combination with a battery storage system is particularly effective, as it buffers surplus energy even when the vehicle is parked at work. Typical charging times with solar power alone are four to seven hours. Plan your charging time at home accordingly.

Option 6: Feeding into the grid and energy sharing

Classic feed-in tariff according to the EEG (Renewable Energy Sources Act)

In 2026, the standard feed-in tariff will still yield around 7,94 cents per kilowatt-hour for systems up to 10 kWp. Above that size, the rate decreases gradually. Those who cannot store or consume the surplus electricity themselves are guaranteed this compensation for 20 years. Applications are submitted through the grid operator and the market master data register. For existing systems, the feed-in tariff that was set at the time of commissioning applies. For older systems, this tariff can be significantly higher.

Energy sharing as a new option since 2026

Since June 2026, energy sharing, as defined in Section 42c of the German Energy Industry Act (EnWG), has complemented traditional feed-in. Plant owners sell their surplus electricity directly to neighbors on the same low-voltage network, typically at 12 to 15 cents per kilowatt-hour. The buyer pays below market price, while the seller receives more than the feed-in tariff. Legally, this model is equivalent to traditional electricity supply. However, the electricity remains in the local grid, thus promoting the expansion of regional generation.

The process is handled via digital energy platforms or municipal utilities with the appropriate license. This model opens up new possibilities for apartment buildings and neighborhood projects. Technical implementation requires a smart meter and suitable metering concepts. Anyone considering energy sharing should speak with their local grid operator and check what metering equipment is already in place. In many cases, simply replacing the old meter is sufficient.

When is which option most worthwhile?

Comparison table of all six options

The six options differ significantly in terms of investment, effort, and impact. It's important to note that these values ​​can vary considerably depending on system size, consumption profile, and local funding opportunities. Nevertheless, they serve as a good guideline. The decision regarding the optimal order always depends on the individual circumstances.

Possibility	Investment	Self-consumption boost	Amortization
timing	0 to 300 Euro	5 to 15 percent	rinse
heater	300 to 2.000 Euro	500 to 1.500 kWh	4 to 10 years
Battery storage	6.000 to 11.000 Euro	30 to 40 percent	10 to 18 years
Heat pump	18.000 to 30.000 Euro	30 percent plus	8 to 15 years
Electric car wallbox	800 to 2.000 Euro	10 to 20 percent	3 to 6 years
Feed-in EEG	no extra	direct proceeds	constantly

Typical sequence for expansion

Most households start with a timer and an immersion heater. Both are inexpensive and provide immediate relief. Next comes battery storage, provided the system is large enough and there is high evening consumption. A wallbox and heat pump complete the setup for fully electrified homes. Those who also drive an electric car and are replacing an existing gas or oil heating system can reverse the order and install the heat pump and wallbox first.

A systematic review before investing saves time and money. Our free PV system checklist guides you through the most important questions regarding your roof, meter, and consumption profile. This allows you to determine the ideal sequence for your needs, avoiding the need to replace individual components later. It's also worth checking current electricity prices with your current provider. Dynamic tariffs make time-based control and storage even more attractive.

Conclusion

Making good use of excess PV power will be the most important factor for the profitability of a solar system in 2026. Time-based controls and immersion heaters offer a cost-effective start, battery storage and heat pumps boost self-consumption to peak levels, and electric vehicles deliver the most economical mileage. Which combination is most beneficial for you depends on your heating system, mobility needs, and budget. If you have questions about the right combination, we offer personal consultations from our pick-up point in Hildesheim, by phone, or via WhatsApp. An individual assessment will quickly show which component is most worthwhile first and how much savings are realistically achievable.