Which size should a photovoltaic system have?

Since self-generated solar power is cheaper than electricity to the typical household customer tariff, the highest possible self-consumption rate is decisive for most operators. In practice, this depends on a large number of factors. The most important are the ratio of the amount of energy produced and consumed and the consumption profile (i.e. when and how much electricity is used in a day). A PV system in Central Europe annually produces between 850 and 1,100 kilowatt hours per kWp of installed capacity. A plant with 5 kWp generates approximately the amount of electricity that is consumed by a family of four on average. However, generation and consumption do not always take place at the same time. The typical self-consumption rate without further measures in this case is only about 30 percent. With intelligent energy management systems for consumer control and temporary storage of solar power, this proportion can be significantly increased. The alternative is a comparatively smaller PV system, where the absolute amount of self-generated and used solar power is smaller.