Design
In order to achieve maximum efficiency, please try to find an installation site, which is shadow-free all day. The maximum energy yield will be achieved by a solar panel facing southwards.
The ideal exposition angle depends on installation site and utilisation period. If you intend to utilise the system all-year, we recommend optimising the angle to match with the winter season, as this is the time of the year providing for the least energy supply. In regions frequently exposed to snowfall, an even steeper angle is advisable in order to allow for the snow to slip off the installation and to exploit the snow’s reflection. Deviations of up to +/- 20° from ideal inclination angle and south-facing position will affect the energy yield to a minor extent only (approx. 5%).
Which output will your solar system produce?
A solar cell’s output is the product of current strength and voltage.
In order to achieve the respectively appropriate output for various applications, single solar cells are interconnected with each other to form larger units. In serial connection, the current will flow through each cell in sequence, which increases the voltage. If solar cells are connected in parallel, the current will only flow through one cell and then join the current coming from other cells. This increases the current strength.
A solar system’s output depends on solar radiation and temperature.
The solar radiation can generally be optimised by aligning the plant southwards. Apart from the alignment, weather conditions play a decisive role. Sunny weather (radiation of approx. 1000 W/m²) facilitates maximum energy production (100%). However, even in bad weather conditions solar cells will produce electricity: when clouds obliterate the sun, solar cells still produce about 60% energy (see illustration). In most sulky rainy weather, they produce around 20% of their maximum output.
Furthermore, the temperature influences the efficiency of solar cells. The lower the ambient temperature is, the more output will be generated by the solar cells. However, this factor is far less significant than solar radiation.