Solar Thermal energy vs photovoltaics

You are interested in harnessing free solar energy and are now considering which technology is the right choice for you? Currently, there are two types of solar systems on the market - solar thermal and photovoltaic. Both systems harness solar energy, but they differ in their functionality and benefits. While photovoltaic systems generate electricity, solar thermal systems generate heat, which can be consumed directly or stored for later use. The right system for you depends on various factors, such as your energy requirements and the available space for installation. We will explain the advantages of solar thermal technology.

Advantages from our AKOTEC solar thermal systems

Utilization of environmentally friendly energy sources
Reduction of heating costs by up to 50%
Active environmental protection through carbon dioxide reduction
Extended lifespan exceeding 25 years
Collectors can serve as privacy screens simultaneously
Versatile applications: heating, domestic hot water, pool heating, etc.

Low maintenance costs
Rapid replacement in case of damage thanks to spare tubes
Independence from rising energy prices
100 % Made in Germany
Usable in both summer and winter
Enhanced energy efficiency compared to photovoltaics

Numbers, data and facts about solar thermal

Energy Cost Savings

The cause of the larger surface area and cost efficiency of solar thermal energy lies in two main factors. Firstly, its efficiency is significantly higher than that of photovoltaics. Secondly, the demand for thermal energy and the potential for self-consumption are significantly greater. Conversely, in the case of photovoltaics, this leads to the need for expensive electricity storage for high self-consumption. Furthermore, post-heating with electrical energy is extremely cost-inefficient. *

Lower initial costs
Reduced space requirements
Higher energy demand, hence greater cost savings

Yield Comparison

Photovoltaics (PV) are versatile due to the electricity they generate. The heat produced by solar thermal is relatively unidimensional in its application for residential use. However, the demand for thermal energy significantly outweighs the demand for electricity, accounting for 85% of the total energy consumption. Of this, hot water represents approximately 13%, space heating 72%, and electrical energy just 15%.

Consequently, when opting for solar thermal, the potential for savings is significantly higher, as there is simply more to save in this regard.*

Higher efficiency compared to PV
Increased yield, as solar gains are achieved even in diffuse light conditions
Applicable for: showers, dishwashers, washing machines, domestic hot water, pool heating, space heating, process heat, etc.

The cost-effectiveness of a solar system depends not only on its performance metrics but also on its costs. For example, an AKOTEC solar thermal system, including installation, is approximately €11,000, while a comparable photovoltaic system with a storage unit costs about €19,500. Both cost estimates include 50% of material costs as installation expenses. Of course, actual prices may vary in practice, as there are many different factors to consider.

However, it's important to note that neither of these total costs takes into account subsidies for solar systems and solar collectors. Currently (as of March 2023), photovoltaic systems, components, and installation are exempt from value-added tax (19%). In contrast, solar thermal systems benefit from significantly higher incentives. The system, its installation, and necessary structural modifications are subsidized at a rate of 25%, and an additional 10% subsidy can be applied for heating system replacements. Planning and construction supervision can also receive a 50% subsidy (BAFA). With the right information, it's possible to purchase a solar system today and optimize its costs.

Directs comparison between solar thermal and photovoltaic

A direct comparison between solar thermal and photovoltaic systems is not always straightforward and precise, as their benefits and operating mechanisms differ significantly. Nevertheless, we have attempted to compare the key components of both systems. The provided information may vary depending on household conditions and usage patterns.

In general, it can be stated that both systems have their own merits and can be effectively combined. Solar thermal systems require less collector area and do not necessarily need to be installed on the roof. Additionally, in existing buildings, solar thermal systems can generate up to 50% of the required heat energy, leading to substantial reductions in energy costs. Furthermore, with the assistance of appropriate incentives, at least 25% of the investment costs can be reimbursed.

Benefits at one glance

Solar thermal

If you're seeking a reliable and cost-effective method for hot water production or heating support, solar thermal technology is the best choice. Unlike photovoltaics, solar thermal technology is specifically designed for converting solar energy into thermal energy. This thermal energy can be directly consumed or stored without losses. Especially in situations where there is a high demand for heat, a solar thermal system can be the environmentally friendly and cost-effective method for generating energy. Furthermore, the initial investment costs are lower, the lifespan is longer, and overall energy efficiency is higher.

Photovoltaics

Photovoltaics, on the other hand, is a suitable option when the generated electricity is meant for direct use or grid injection. This is particularly the case when there is a high demand for electrical energy, such as in commercial buildings, industrial facilities, or residential households with heat pumps and electric vehicles. In these instances, it makes sense to convert solar energy into electricity. It's important to note that the overall energy cost savings are generally lower, as the energy demand for heating and hot water is higher. Combining both technologies is also possible and advisable to maximize the benefits of solar energy.

Subsidies opportunities

Whether it's a solar thermal system or photovoltaics, the acquisition costs are not insignificant. Opt for a solar system from AKOTEC, and you can take advantage of various funding opportunities that will allow you to save at least 25% of your investment costs!

ALL INFORMATION ABOUT SOLAR THERMAL SUBSIDIES

FAQ's

WHAT'S BETTER: SOLAR THERMAL OR PHOTOVOLTAIC?

When deciding between a solar thermal system and photovoltaics, it primarily depends on your individual needs and priorities. Solar thermal is ideal if your main goal is to generate hot water and heating energy. Photovoltaics, on the other hand, is better suited if your aim is to produce electricity to power your household or feed it into the public grid. A combination of both systems is also possible and, depending on your requirements and site conditions, it may be the best option. Consult with our experts to find the optimal solution for your needs.

SOLAR THERMAL IN WINTER?

The effectiveness of solar thermal systems during the winter depends on various factors. Although sunlight is less abundant during the winter, a solar thermal system can still generate enough heat to provide hot water and heating. When designing the system, it should be optimally sized to meet the needs and required heat levels. The size of the collector area and the storage capacity plays a crucial role in this regard. Compared to photovoltaics, solar thermal systems are more effective for heat generation during the winter.

SOLAR THERMAL IN SUMMER?

In the summer, solar thermal systems are highly effective as sunlight levels are at their peak. Solar collectors can produce substantial amounts of energy, which can be used for hot water production and heating support. During system design, it's essential to ensure that there is no risk of system overheating when excess heat isn't utilized. Ideally, the collectors or tubes should have integrated overheat protection.

WHAT HAPPENS WITH SOLAR THERMAL DURING POWER OUTAGES?

A solar thermal system harnesses the sun's energy to produce heat. In the event of a power outage, the system continues to generate heat energy as it operates independently of the electrical grid. However, the pump requires electricity to circulate the heat transfer fluid through the system. If the power fails, the pump can't operate, and the heat transfer ceases. To address this issue, solar stations can be connected to a backup power source. In such cases, it's advisable to consult with a trusted electrician.

HOW MUCH PERCENTAGE CAN YOU SAVE WITH SOLAR THERMAL?

When you opt for the installation of a solar thermal system, you can save up to 50% of the energy costs for hot water production and heating. However, the exact savings depend on various factors such as the system's size, energy requirements, sunlight exposure, and user behavior. Thanks to these substantial figures, investing in a solar thermal system is worthwhile, as it can lead to significant long-term cost savings.

CAN YOU COMBINE SOLAR THERMAL AND PHOTOVOLTAICS?

Yes, it is possible to combine solar thermal and photovoltaic in a single system. This type of system is known as a hybrid solar system. While photovoltaic technology converts solar energy into electricity, solar thermal utilizes solar energy to produce heat for domestic hot water and heating. By integrating both technologies, you can leverage the advantages of each, thereby enhancing the energy yield and overall efficiency of the system. However, it's important to note that the installation of a hybrid solar system is generally more expensive than a single-technology system. If you are interested in a solar thermal system, you can contact us to learn about the various options and associated costs.

HOW MANY SQUARE METERS OF SOLAR THERMAL FOR A SINGLE-FAMILY HOUSE?

The required collector area for a solar thermal system depends on its intended purpose. Approximately 3 m² of collector area is sufficient for domestic hot water heating, while around 8 m² is needed for heating support. Ideally, the specific requirements are determined, and the system is optimally designed to maximize yields during transitional periods and in the winter.

IS PHOTOVOLTAICS WORTH IT AT ALL?

Photovoltaics are definitely worthwhile! By harnessing solar energy, you not only contribute to environmental preservation but also reduce your electricity costs. Ultimately, your specific needs will determine your choice. Both systems have a valid purpose.

Interested? We would like to advise you.

info@akotec.eu

+49 3331 25 716 30

+49 3331 25 59 996

Or text us:

ATTENTION: The following comparison is not universally applicable to every building and heating system and is subject to assumptions and estimates of future developments. In one scenario, approximately 40 m² of roof space was entirely covered with 20 PV modules (monocrystalline, 2 m², 350 Wp each) and a 10 kWh electricity storage system was installed. Additionally, an electric heating element was integrated into the hot water tank. In the second scenario, 2 AKOTEC Weiser-Protect 30 collectors, totaling 60 tubes with a gross collector area of 9.78 m², were used. No electric auxiliary heating is employed. Both houses are equipped with a gas boiler. Other parameters for the analysis include an electricity purchase price of 37.1 cents/kWh, a gas purchase price of 11 cents/kWh, and an electricity feed-in tariff of 8.2 cents/kWh (average values from January/February 2023). Inflation rates were aligned with the inflation of the first half of 2022, but set slightly lower due to exceptional circumstances (gas +10% p.a., electricity +2% p.a.). Both technologies were compared with the same house without any renewable energy utilization, meaning pure gas heating operation. *