Solar power for the electric car - photovoltaic system for tenants and homeowners

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Photovoltaic system contribution image

Is photovoltaics a great advantage for electromobility or is the home photovoltaic system more appearance than reality? 

In this article you will learn when it is worthwhile to install your own PV system, who is allowed to install your own PV system, what you should pay attention to and what photovoltaic subsidies are available.

Table of contents

Especially in the wake of gasoline price increases, a switch to electromobility has become increasingly attractive. We could already answer the question of whether an e-car is still financially worthwhile even with rising electricity prices with a "yes". However, one important aspect that is often given too little attention is that you cannot generate your own gasoline, but you can generate your own electricity! There are therefore some innovative approaches, such as using the e-car as a storage unit for the electricity you generate yourself. With so-called bidirectional charging, the electricity can be used again to supply the house electricity when needed. But it doesn't always have to be a highly complex energy solution. What if you just want to install a few solar panels on your home to support your own energy consumption? Preferably with the integrated wallbox to charge your own e-car with the self-generated electricity? That's exactly what this article is about.

 

When is photovoltaics worthwhile?

The first step is to analyze your own living situation. If you live in your own home, you probably have enough free space to operate your own photovoltaic system. But also for tenants a photovoltaic system can often be worthwhile. Delivered solar electricity is about four times more expensive than self-generated electricity. This is due to various taxes, charges and levies. The rule of thumb is that a photovoltaic system can cover about 30% of your own energy consumption. With a connected energy storage system and the corresponding comprehensive energy concept, up to 70 %. This is due to the fact that the sun does not shine constantly all day and all year and that one is subject to changes in the weather. Therefore, especially in the midday hours, the power generation is high. You can therefore either store surplus electricity in an energy storage system or feed it back into the grid and sell it. All you need is a feed-in meter or bidirectional meter and the appropriate registration with the grid operator. This way, you can even profit from your photovoltaic system when you are not at home!

Inforgraphic: How does a photovoltaic system work?

What are the requirements for a PV system?

Free surfaces, such as roofs, are the most important prerequisite for your own PV system. The optimal orientation of these surfaces is to the south, but deviating orientations can also work sufficiently well. The generated energy is lower compared to the orientation to the south. Especially for flat roofs, but also for all others, it is also recommended to perform a structural analysis calculation before installing photovoltaics. This will ensure that the load-bearing capacity of the roof is sufficient for the PV system and that it will not be left in danger of collapse after installation. In addition to roofs, balcony facades or certain house walls may also be suitable for a PV system. In any case, you should avoid shadows on the planned PV system. This also applies to potential shadows that may occur in the future, e.g. due to growing trees. If you are a tenant, it is worth talking to your landlord or the building community to set up an initiative and find like-minded people.

Rooftop or in-roof photovoltaics?

The advantages of photovoltaics are obvious. Whether a PV system on the roof meets one's own aesthetic expectations, however, is another matter. Fortunately, there are various options for mounting the PV system. On-roof mounting is the classic, which probably everyone has seen on one or the other house roof. Here, metal frames are mounted on the roof, which hold the individual solar panels. With this method, damaged modules can be easily replaced and there is flexibility in expanding the PV system. Finally, there is no major intervention in the structure of the house. On the other hand, rooftop mounting is visually quite conspicuous and protrudes a good deal above the actual roof.

 

In-roof mounting, on the other hand, replaces the upper layer of the roof and virtually places the solar panels inside the roof. Visually, this is the more elegant solution. On the other hand, the installation is more complex, more expensive and should be planned right from the start, especially for new buildings. If you want to upgrade your new building on your own afterwards, caution is advised. Discuss your plans with your contractor or the appropriate trade to avoid voiding the warranty on your new roof. Replacing individual solar panels or expanding your PV system is also much more costly. Apart from these two options, there are still many individual solutions. A very good first step to find out if a PV system is worthwhile for you is the energy consulting of the consumer center or at the energy supplier.

Difference in-roof and on-roof photovoltaic system

Legal - Who is allowed to install a photovoltaic system?

Before such a large construction project, it is important to fulfill the legal requirements and to safeguard yourself. We answer important questions that many private individuals have in the course of installing a photovoltaic system.

Difference in-roof and on-roof photovoltaic system

Legal - Who is allowed to install a photovoltaic system?

Before such a large construction project, it is important to fulfill the legal requirements and to safeguard yourself. We answer important questions that many private individuals have in the course of installing a photovoltaic system.

Registration with the network operator, in the market master data register and with the tax office

All plants that generate electricity must be entered in the market master data register within one month. Failure to do so may result in a fine and the loss of the feed-in tariff. Registration is done online via the portal of the market master data register. If you are planning a photovoltaic system that produces more electricity than you consume, registration with the grid operator for feeding the excess electricity into the grid is mandatory. For more details, it is best to contact your local grid operator. Since operating your own photovoltaic system is a commercial activity, you must also report this to your tax office. Since you generate profits from the electricity fed into the grid, these are subject to income tax. Both the electricity you feed into the grid and the electricity you use yourself are also subject to sales tax.

Excursus: Photovoltaic system for rental apartments?

As confirmed by the Stuttgart District Court in March 2020, landlords cannot prohibit the installation of balcony photovoltaics without good cause. The prerequisite for approval is that it is permissible under building law, has been installed professionally, and that no damage of any kind remains to the fabric of the building in the event of subsequent dismantling. Do not risk a legal dispute, but speak openly with your landlord. As an alternative, there is still the possibility of renting the roof of the house in which the rented apartment is located, or even another one. You should also clarify this in conversation with the owners.

What photovoltaic subsidies are available?

The compensation for solar power that you feed into the grid is technically a subsidy. The German government is constantly discussing how exactly it should develop in the future. The state-owned banking group KfW promotes renewable energies with a low-interest loan. The subsidy product "Renewable Energies - Standard (270)" supports plants for the generation of electricity and heat as well as grids and storage facilities with an effective annual interest rate of only 2.56%. This is available to private individuals as well as companies and public institutions. Some federal states also offer their own subsidy projects. You should find out whether you are eligible for one of these if you want to start implementing it promptly, as the funding pots can be exhausted quickly. It pays to be quick!

Use it yourself or feed it in - The comparison

What is actually more worthwhile, using it yourself or feeding it into the grid? The more solar power you use yourself, the more it pays off to invest in a PV system. In the night of 05.07.22, the German government agreed on an average feed-in tariff according to the EEG of 8.60 cents per kilowatt hour for solar power from small PV systems. This applies to new installations from 01 January 2023, so compared to the average 36 cents that a consumer pays to buy electricity from the utility, much lower. It is therefore most efficient to also consume the self-generated solar power yourself. That's why energy storage is such a good idea. This way, you don't have to buy expensive electricity at night, but can continue to use the electricity you produce yourself. So, if possible, self-consumption is always the cheaper and more financially rewarding alternative compared to feeding it into the grid.

What is the cost of a PV system?

One thing in advance: A private photovoltaic system is cheaper than ever! The cost of a PV system depends on your own electricity consumption and the power of the photovoltaic system. The higher your electricity consumption, the more solar surface you need and the higher the costs will be. With an exemplary power consumption of 4.000 kWh/year the photovoltaic system should have about 4kWpeak power. This is available from around 8,000 euros . A suitable storage unit would cost an additional 6,500 euros. Which storage dimension makes sense depends on the installed power of the PV system and is between 5 and 15 kWh for single-family houses. Per kWh storage capacity you can calculatewith prices between 1,000 and 1,800 Eurorechnet. Furthermore, you should also take into account the cost of installation. In any case, a PV system is a long-term investment. The costs will be amortized in most cases only after a few years. For a complete photovoltaic system with a corresponding energy concept, storage and integration of a wallbox, you should obtain an offer from your local energy supplier such as SachsenEnergie.

 

Photovoltaic system for home: The environmentally friendly way to reduce electricity costs and charge your own e-car!

Many people have recently become aware of the topic of photovoltaic systems for private individuals due to their new e-car. This is very pleasing, after all, you can not only save cash, but also generate climate-neutral electricity in the process! Proper planning is the be-all and end-all for such a project. Clarify in advance whether your living situation is suitable for a photovoltaic system and how high your electricity demand is. Financially, however, it is always most worthwhile if you also consume your self-generated electricity yourself. Due to the dependence on the sun, an electricity storage system is also a good idea, so you can supply your e-car with solar power even in bad weather or at night. The KfW subsidy 270 for renewable energies also makes such a project palatable. Also keep an eye out for other subsidies from the federal states, these are quickly out of stock! For a comprehensive energy concept and personal advice, you should always contact your local energy supplier.

 

If you have any further questions or comments on the subject of photovoltaics and power generation for the private wallbox, please feel free to contact us at frag@umschalten.de!

A contribution by Marcel Duparré

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