Solar system - electricity and heat from solar energy

Just one hour of sunlight is enough to completely cover humanity’s annual energy needs. With a solar system from Viessmann, you can harness this free and inexhaustible energy source in your own home.

While solar thermal collectors convert incoming radiation into heat, solar photovoltaic modules generate electricity. But how does a solar system work? What are the differences between photovoltaic and solar thermal energy, and how can both systems be best integrated into a home?

A solar thermal system converts radiant energy into heat.

Viessmann’s solar thermal system utilizes the sun’s free radiation to generate heat for domestic hot water and space heating. This requires solar collectors, a solar cylinder, and a network of pipes connecting all components.

Solar collectors in a solar thermal system perform the most critical function, absorbing solar radiation, converting it into thermal energy, and transferring it to the solar environment. You can choose between flat-plate collectors, such as the Vitosol 200-FM , or evacuated tube collectors, such as the Vitosol 200-TM. Evacuated tube collectors provide maximum efficiency over the smallest surfaces.

Depending on the type of solar thermal system, a pump delivers heated solar fluid through a heat exchanger to a DHW cylinder or a heating water buffer tank. DHW cylinders, such as the Vitocell 100-B/-W from Viessmann, are used when the solar thermal system’s function is to heat domestic hot water. If the system is also intended to provide space heating, it can be combined with, for example, the Vitocell 360-M , a multi-mode heating water buffer tank with integrated collector connection. Both systems absorb the solar system’s thermal energy and store it until hot water or space heating is required. Optimally coordinated complete solutions, such as the Viessmann Vitosol 141-FM solar DHW package , ensure maximum efficiency.

Photovoltaics generate electricity from solar radiation

A photovoltaic system operates differently from a solar thermal system. This is because photovoltaic systems convert solar radiation into electrical energy. To achieve this, in addition to solar panels or solar modules, the system includes an inverter and additional energy storage.

Solar panels, like the Viessmann Vitovolt 300 solar PV system, consist of multiple solar cells. They use the photoelectric effect to convert radiant energy into direct current (DC). An inverter then generates alternating current (AC). This is necessary for using the electricity in the home or exporting it to the public grid. While solar systems were once designed more for the latter, self-consumption is now more cost-effective. This is because homeowners need to purchase less electricity from the grid, thus saving more on energy costs. However, electricity is almost always needed at times when the solar PV system isn’t producing it, such as in the evening or at night. Using an energy storage system like the Viessmann Vitocharge can mitigate this shift. With a battery system, solar energy collected during the day will also be available at night. This helps make you self-sufficient and significantly reduces your energy bills.

Who is the Viessmann solar system suitable for?

Using photovoltaics and solar thermal energy is always beneficial when solar collectors and rooftop solar modules can collect a lot of energy. This requires:

• Sufficient space for collectors and solar panels
• south-facing roof for solar system
• Roof surface with a slope of 30 to 40 degrees
• Trees, houses or mountains that do not cast a shadow on the house.

Even if your roof doesn’t meet all the requirements, a Viessmann solar system can still be beneficial. Using a scaffolding system, you can tilt the collectors and solar modules to the optimal angle. If the roof faces east or west, the collector and module surfaces must be larger. Otherwise, yields will be significantly lower than with a south-facing roof.

Improving economic efficiency through self-consumption

The Viessmann energy storage system increases the self-consumption of self-generated electricity, thereby increasing the efficiency of the photovoltaic system. The system charges the energy storage system when your home doesn’t need electricity. This energy is then used as needed, for example, to power electrical appliances. If the energy storage system is fully charged and no consumers are connected, excess energy is exported to the grid and billed accordingly.