In Slovakia, the intensity of solar radiation falling on the horizontal surface of the collectors in most areas ranges from 3 to 3.4 kWh/m2 per day, on the basis of which we can classify our country as one of the countries with medium radiation values.
Solar collectors process approximately 50 to 60% of this energy. Each square meter thus accounts for 1.5 to 3 kWh of energy per day, which in practice represents the preparation of 40 to 60 liters of 50 °C hot domestic water. We record the most solar radiation throughout the year in the south of Slovakia and the least in Orava and Kysucie. The most significant differences arise in the summer season, when there is the most significant excess of solar heat gain. The amount of incident solar energy reaches its maximum in July, its minimum at the turn of December and January. However, from the point of view of the utilization of solar energy by solar collectors, the difference between these coldest and warmest regions of Slovakia is only approximately 15%. It can therefore be said that Slovakia has a relatively large potential in terms of the use of solar energy.