We all know that a solar system, solar thermal system and photovoltaic converts solar energy into another form of energy. However, these terms are not to be used interchangeably as there are some important differences that everyone should be aware of. While a photovoltaic system produces electricity, a solar thermal system only produces heat. Heat or electricity from solar energy is the most sustainable way of generating energy. The radiation energy reaching the surface of our earth depends on the distance between the sun and the earth (season) and the time of day.

Anyone who wants to become largely independent of energy prices and at the same time want to save on energy costs will find an interesting alternative in a solar system. Since the acquisition costs for these systems have fallen sharply in recent years, they are enjoying increasing popularity.

This is how a solar thermal system works
The solar thermal use of solar energy is not so new, but goes back to 800 BC. BC, when the sun’s rays were brought together for concave and focal mirrors. It was not until the 18th century that the researcher Horace-Bénédict invented a precursor to today’s solar panels. However, the invention only became interesting at the time of the oil crisis around 1970, when alternative energy sources were being sought.

In contrast to PV (photovoltaic) modules, solar thermal modules are black panels, which are also known as flat-plate collectors, pipes or evacuated tube collectors. These solar thermal modules are called solar collectors because they are charged with maximum heat due to their black color. The carrier liquid (antifreeze) inside absorbs the heat and transports it to the solar storage tank, where it is transferred to the water for daily use or the heating system. Combinations of solar thermal and PV systems are also possible. The size of the solar collectors should of course be precisely tailored to the hot water requirements of the users, since excess heat cannot be fed into the grid like electricity.

Solar power from your own roof is ideal because it can greatly reduce the electricity bill. How much everyone can save in the future naturally depends on the respective hot water requirements. However, this can be determined online with a free solar power calculator. Factors such as the number of people living in the unit and whether special extras such as a heated pool or greenhouse need to be catered for are decisive.

Of course, solar is not only an option for homeowners, but industrial heat can also be generated by solar thermal power plants. Thermal solar power plants work like thermal solar systems, but only at very high temperatures and on a much larger scale. In general, thermal energy is converted into electricity for industry, but this can also be used directly as thermal energy for chemical processes.

The amortization times of solar thermal systems are impressive.

The financial amortization is about eight years, while the energetic is already 1.5 years.

In years past, homeowners generally dismissed this issue as “too expensive.” But times change. Thanks to various subsidies, the new, expensive technology was quickly brought to market. A typical PV system (photovoltaic system) cost around 20 years ago about five times what it is today. But it is not just the significantly lower purchase price that makes a PV system much more interesting today than it used to be, but also the special promotion of alternative energies and the constantly rising electricity prices. Because in Germany we have one of the highest energy prices in the world and a further strong increase is expected. In addition to stagnating wages and rising inflation, the aim is to at least get energy costs under control and thus effectively relieve the burden on the wallet.

But what exactly is a photovoltaic system?
Solar power is one of the most commonly used types of renewable energy, which is generated via a photovoltaic system. Large-area solar cells made of silicon convert the sun’s rays (solar energy) that hit them into electricity. When the sun’s rays hit the silicon of a solar cell, direct current is generated by what is known as the photovoltaic process. In order to be able to use this in the household, it is converted into the alternating current that can be used in the household by means of an intermediate inverter. The alternating current obtained in this way is then consumed by a wide variety of electrical devices. Unneeded energy is fed into the public power grid or temporarily stored in a “solar storage tank” so that it can then be used on bad weather days or at night when no solar energy is being produced.

When is a photovoltaic system on the roof worthwhile?
As more and more homeowners are fed up with the rising energy costs, according to a survey, every fourth person is planning to purchase a photovoltaic or solar system for 2022. For many, photovoltaics is a profitable investment that is worthwhile. If all influencing factors are taken into account, a benefit of more than five percent can be achieved.

In general, one can say that photovoltaics is worthwhile. How big the savings are for each individual depends on the following influencing factors:

The size of the available roof area.
From the angle of inclination and the orientation of the respective PV system.
Components used such as modules, mounting system, cables and inverters. The inverter is the central element in the PV system, because it converts the direct current generated by the solar power into alternating current. The electrical energy is then consumed by electrical devices in the household or fed into the public grid. An MPP tracker (approx. 98 percent efficiency) is integrated into the inverter, which has to ensure that the PV system always delivers the best possible performance. This happens at the so-called maximum power point, which is not constant but depends on external influences such as temperature and solar radiation.

Why photovoltaics? – Advantages of photovoltaics
You reduce your electricity costs to 8-12 cents per kilowatt hour with the advantages of photovoltaics
You secure long-term returns thanks to attractive EEG
They protect and secure the environment with self-produced green electricity
You make yourself independent of rising electricity prices thanks to a photovoltaic system

1. Reduce your electricity costs
A kilowatt hour (kWh) of electricity currently costs around 35 cents in Germany. Electricity from a photovoltaic system can already be generated for 8-12 cents per kWh. That means you save 22-27 cents for every kilowatt hour you use.

With the installation of a photovoltaic system, your annual electricity costs drop significantly and noticeably. If the system is combined with an electricity storage system, the savings increase further. With a power storage unit, you can use your own solar power even when the sun is not shining, further reducing the amount of power drawn from the grid. As the word suggests, you store the electricity generated in a memory for later recall. So you are not forced to use the electricity directly.

2. Secure a long-term return
Photovoltaic is one of the safest forms of investment. The reason for this is the regular, secure income from your investment. On the one hand, the feed-in tariff guaranteed for 20 years ensures fixed income for system operators. There is also funding from the EEG. You are welcome to collect further information on this and contact us if you have any questions.

3. Protect and secure the environment
For many system operators, becoming active and protecting the environment is another reason why they opt for photovoltaics. Photovoltaic systems draw energy from the sun and convert it directly into electricity. In contrast to conventional power plants such as a coal-fired power plant, they do not emit any climate-impacting CO2 and are therefore 100% climate-neutral.

If you choose a photovoltaic system, you also choose to protect the environment. Some of the things on the Paris climate agreement were also discussed here and further options were shown for protecting the environment.

4. Independence from electricity prices – advantage of photovoltaics
With the purchase of a photovoltaic system, you are no longer forced to follow rising electricity prices. Thanks to photovoltaic systems, you can make significant savings here and save 22-27 cents per kilowatt hour. Since it is not foreseeable to what extent electricity prices will continue to rise, it is highly recommended to install a photovoltaic system and make you independent of electricity.

Difference between photovoltaic and solar thermal? There are various concepts related to energy from the sun, which sometimes get mixed up. The two most important are photovoltaic and solar thermal. Both are technologies for generating energy that use the power of the sun – in different ways. With a photovoltaic system, the power of the sun is converted into electricity, which can then be used in the house. It’s different in a solar thermal system: instead of solar panels, solar collectors capture the sun’s rays. This heats a liquid in thin tubes, creating steam. In this way, the solar heat is transferred to a storage tank in the house, where it can be used.

This describes the main difference (difference between photovoltaics and solar thermal): Photovoltaics produces electricity; Solar thermal generates heat. But which of the two systems has the advantage? After all, each square meter of roof or facade area can only be used once (apart from combination modules, which only divide the module area between panels and collectors).

The advantage of photovoltaics is its versatility: electricity can be used in all devices in the household, including electric cars. And it can also power a heat pump heater. A solar thermal system, on the other hand, can only do one thing: generate heat. Theoretically, cooling is also possible using a heat exchanger, but this is seldom economical – in contrast to modern heat pumps, which can do both when combined with comfort ventilation. In addition, only photovoltaics can feed energy into the grid.

So there is a clear advantage for photovoltaics? Not one hundred percent. Solar thermal systems are very efficient because the energy is not converted; less roof area is therefore required for the heating energy than with a photovoltaic system. In addition, solar thermal systems are cheaper to buy. However, purchased electricity is more expensive per kilowatt hour than heat. Switzerland’s Energy Strategy 2050 sees clear advantages in the electrification of heat. Which of the systems is more suitable and whether a combination might make sense varies from building to building. However, expert advice can quickly clarify this question.

We have put together some interesting information here for you on the subject of photovoltaic systems!

You should note this before installation
Before you become your own power generator, you should take a close look at your roof – preferably with the support of a specialist company. Because not every roof is suitable for the optimal operation of a photovoltaic system or solar modules.

The following basic ideas should be taken into account during planning:

Is the solar radiation high enough?
There should be no intensive shading from other buildings or tall trees. At least one sun exposure of 6-8 hours a day.
For maximum electricity yield, the ideal roof faces south and has an angle of inclination of between 30 and 45 degrees.
If you would like to use as much solar power as possible yourself and harvest a sufficiently high yield throughout the day, flatter east/west roofs are a good prerequisite for this.
Do you have a sufficiently large roof area?
The more space is available, the more cost-effective the system will be per kilowatt peak
If these points are given, you can now start thinking about the purchase of photovoltaic systems.