The energy transition is also significantly impacting the heating systems of properties. In Finland, heating is one of the largest sources of energy consumption and costs, which is why increasing efficiency is a central part of economically and environmentally sustainable construction and renovation. Solar energy offers significant opportunities for this when utilized as part of an overall heating solution. Properly integrated solar energy supports other forms of heating, reduces the need for purchased energy, and improves the energy efficiency of the entire system.
Solar energy as part of a modern heating system
The use of solar energy for heating is based on two technologies: solar power and solar thermal. A solar power system produces electricity that can be used directly for the building's electrical appliances and the operation of the heating system. A solar thermal system, in turn, converts solar radiation directly into heat, which is stored in an accumulator tank and used for heating domestic hot water or spaces.
In a comprehensive solution, solar energy does not replace the main heating system, but complements it. In Finland's climatic conditions, solar energy production is concentrated in the spring and summer, while the need for heating is at its peak during the winter season. Therefore, solar energy works best in a hybrid model, where it supports, for example, a heat pump, district heating, or another base heating form.
The role of solar thermal energy in heating domestic hot water and spaces
Solar thermal systems are particularly suitable for the production of hot water, which accounts for a significant portion of a building's annual energy consumption. During the summer season, solar thermal energy can cover a large part, or even almost all, of the energy need for hot water. This is particularly useful in detached houses and properties where hot water consumption is steady throughout the year.
During the winter season, solar thermal production is lower, but it still acts as a source of auxiliary energy. Solar thermal energy reduces the load on the rest of the heating system and improves the annual efficiency of the entire system. A correctly dimensioned accumulator tank is a central part of a functional solar thermal solution, as it enables energy storage and flexible use.
The importance of comprehensive heating system planning
Integrating solar energy into the heating system requires careful planning. The building's energy needs, the existing heating system, the orientation and surface area of the roof, and the consumption habits of the users all critically affect the system's function and profitability. An individual component does not guarantee energy efficiency; the deciding factor is the compatibility and control of the various systems.
The best results are achieved when solar energy is considered at the planning stage as part of the building's entire energy system. Even retrofits can be highly functional when the system is dimensioned realistically and goals are set correctly. In that case, solar energy effectively supports heating without the costs associated with over-dimensioning.
The key benefits of solar energy in the heating system
Integrating solar energy as part of the heating system brings several concrete benefits:
- Reduced heating costs through a decreased need for purchased energy
- Improved energy efficiency and self-sufficiency level for the building
- Significant reduction in carbon dioxide emissions
- More even loading and longer service life for the heating system
- Increased property value and attractiveness due to energy efficiency
Typical heating system combinations
The role of solar energy varies depending on the heating system it is integrated into. The table below illustrates the most common combinations and their benefits:
| Heating system | Role of solar energy | Typical benefit |
| Geothermal heating | Solar power for heat pump operation | Reduced electricity consumption |
| Air-to-water heat pump | Solar power and solar thermal | Better efficiency from spring to autumn |
| District heating | Solar thermal for domestic hot water | Reduced district heating consumption |
| Electric heating | Solar power directly for heating | Significant cost savings |
| Hybrid system | Solar power + solar thermal | Maximum self-sufficiency |
Future prospects and strategic choice
The importance of solar energy as part of heating systems will continue to grow. The development of energy storage technologies, smart control systems, and changes in the energy market support an increasingly broad use of solar energy.
Integrating solar energy into the heating system is a strategic choice that supports both economic and ecological sustainability. When the system is planned as a whole and correctly dimensioned, solar energy is not just an add-on, but an essential part of a functional and future-proof heating solution.
Kardonar Bioenergy Solution helps in finding the right heating system – contact our retailers! In addition to solar energy, we also offer pellet, wood chip, firewood, and hybrid heating systems.