Solar system: advantages and benefits of modern systems

Solar systems make a valuable contribution to climate protection and you benefit from environmentally friendly electricity. They help save energy and money and you take another step towards more independence. After the feed-in tariff has dropped significantly in recent years, homeowners in particular are wondering whether investing in a solar system is still worthwhile. To determine the profitability of photovoltaics, it is important to calculate the costs and yields as realistic as possible in advance. We have put together the most important information for you here.

Table of contents Table of contents A solar system is worthwhile

• How a solar system works
• Feed in electricity from the solar system or use it yourself?
• Photovoltaics: costs and returns
• How useful is electricity storage?
• Realize feed-in tariffs
• Financing and funding opportunities for solar systems

Table of contents Table of contents A solar system is worthwhile

• How a solar system works
• Feed in electricity from the solar system or use it yourself?
• Photovoltaics: costs and returns
• How useful is electricity storage?
• Realize feed-in tariffs
• Financing and funding opportunities for solar systems

Is it profitable to buy a solar system? What does it cost to install the system and what are the expected returns? Many homeowners who are interested in photovoltaics ask themselves these central questions. The prices for solar systems are cheaper than ever - but the feed-in tariff is also falling further. So it alone is no longer a reason to buy a solar system. Because the savings are in self-used electricity, which reduces electricity costs. In addition, independence from the supplier, the use of renewable energies and thus support for climate protection play a role in decision-making. The focus is on new possibilities for storing the generated electricity, because a solar system is worthwhile especially if you can use as much of your own electricity as possible. Last but not least, there is also the question of how the acquisition costs for a solar system can be financed and whether there is still government funding.

How a solar system works

In a photovoltaic system, the solar modules - consisting of interconnected solar cells - convert sunlight into direct current. So-called inverters turn it into household AC. You can use it for your own use or feed it into the public power grid.

Feed in electricity from the solar system or use it yourself?

In the past, owners of solar systems have largely fed the electricity produced into the public grid and received a feed-in tariff from the state. This refinanced the purchase of photovoltaics and even made profits. Due to the lower feed-in tariff, you should rethink. Photovoltaic systems optimized for consumption bring you the greatest possible savings.

It is therefore more lucrative for homeowners to consume the electricity they generate themselves in the home, thereby making them less dependent on the public power grid. You use the savings to refinance the costs of the solar system and permanently lower your monthly electricity bill. You also contribute to climate protection with environmentally conscious and sustainable electricity production.

Tip: If you opt for environmentally friendly driving, a photovoltaic system makes a lot of sense. You charge your electric car with inexpensive solar power from our own production. This reduces electricity costs and the duration of the amortization.

Photovoltaics: costs and returns

In principle, the purchase of a solar system should be carefully planned, because it must match the building and your electricity consumption in order to generate optimal yields. You should therefore always have a reliable calculation of the costs for a solar system and the expected yield done by a specialist who has previously been able to get a precise picture of your roof area on which the solar system is to be installed. However, a rough estimate of the return based on guide values ​​is also possible with just a few key data.

System performance	Electricity production in the year	Space requirements	Approximate cost including assembly
3 kWp	2830 kWh	16.5 sqm	from 7, 000 euros
4.5 kWp	4250 kWh	24.8 sqm	from 10, 000 euros
6 kWp	5660 kWh	about 33 sqm	from. 12, 400 euros
7.5 kWp	7080 kWh	approx.41.2 sqm	from 13, 900 euros
9 kWp	8500 kWh	approx.49.5 sqm	from 16, 400 euros

Source: E.ON

The price per kilowatt peak is a comparative figure for photovoltaic systems, including inverters, installation and commissioning (as of 2020). There are also annual operating costs of around 200 euros. This essentially concerns meter rental, insurance and cleaning costs.

How economical a solar system is depends on three different factors:

• acquisition cost
• geographical location
• Alignment and inclination of the roof area
• Share of self-consumed electricity

The cost of a solar system for your house depends on several factors, such as the power required and the existing roof area.

Photo: iStock / Vicente García Marín de

How useful is electricity storage?

On average, operators of solar systems can use up to 30 percent of the electricity they produce. After all, a photovoltaic system generates the most electricity at lunchtime - however, the least energy is usually used during this time. In the evening, at night or in the dark winter months, however, the electricity yield of the solar system drops. A power storage can store the unused solar power from sunny times for more independence. In the meantime, powerful and long-lasting lithium-ion storage devices have fallen in price and are profitable in the long term.

Physical electricity storage

With a locally operated battery storage, you can increase your self-consumption quota up to 70 percent. But: The cost of self-produced electricity must not exceed the cost of purchasing electricity. What does that mean? A kilowatt hour from a solar system costs an average of 10 cents, but each kilowatt hour from the power grid an average of 30 cents. With a solar system and storage, you can save an average of 20 cents per kilowatt hour. E.ON offers financing options so that you can extend your investment over a longer period of time.

Virtual electricity storage

With this model, you feed the surplus electricity that you produce into the grid, thereby filling a virtual electricity account. In a way, you build up a credit balance, similar to a savings book. On gloomy days, at night or in the winter months, you can simply call up this electricity credit again and use it yourself at affordable prices. So nothing is lost with the E.ON Solar Cloud and you ultimately consume 100 percent of your self-produced electricity equivalent. This variant can also be used as a supplement to the local electricity storage in order to achieve the greatest possible independence.

Realize feed-in tariffs

You will receive a guaranteed amount for feeding the electricity you generate into the public grid, for which the energy suppliers will have to purchase solar power every kilowatt hour. However, the amendment to the Renewable Energy Sources Act (EEG) provides for the continuously falling remuneration of one percent per month.

Nevertheless, installing the solar system pays off because the modules have become cheaper. You can find out the profitability of a solar system in terms of current remuneration rates with the help of photovoltaic computers that are available online.

Having a solar system installed is of course not cheap. But you can cover the acquisition costs with clever financing.

Photo: iStock / anatoliy_gleb

Financing and funding opportunities for solar systems

You can also implement the installation of the solar system without equity by financing the purchase. With the E.ON Sunrate, for example, you save the initial investment and become a photovoltaic owner with monthly installments.

State subsidies for the purchase of a solar system

KfW offers various financing and funding options. This enables you to finance up to 100 percent of your investment costs and repay them with an effective annual interest rate of 1.03 percent. Inquire about regional funding programs in your state and municipality. Because individual federal states also subsidize the purchase of a solar system or an electricity storage. Here is an overview:

state	Funding program	content
Bavaria	PV storage program	Grant of 500 to 3, 200 euros for Battery storage
Rhineland-Palatinate	Solar storage program	100 euros per kWh (up to a maximum of 1, 000 euros) usable storage capacity of a local Electricity storage in connection with a new photovoltaic system
Saxony-Anhalt	Promotion of electricity storage for photovoltaic roof systems	Up to 30 percent of the acquisition costs for a local electricity storage (maximum 5, 000 euros) in connection with a new solar system
Thuringia	Solar Invest	Up to 900 euros per kWp for new ones Photovoltaic systems with battery storage, 300 euros per kWh for a battery storage

* As of March 2020