Installations for the generation of electricity are designed and built for a specific capacity. The installed generation capacity specifies the maximum possible Electricity generation that can be produced by the installation and is usually given in megawatts.

The sum of all installations gives the total installed generation capacity in Germany. An overview of this can be seen in the graph below:

This value is normally higher than the electricity actually generated because wind turbines, solar plants and conventional power plants do not always work to full capacity. Some generation capacity always goes unused, whether this is due to maintenance, the changing wind or sun conditions, or just because power plants adjust their Electricity generation to meet actual demand at a particular time. 

An important difference between conventional and renewable Electricity generation is that many renewable energy installations feed in power depending on availability: wind turbines produce electricity when it is windy and solar plants produce electricity when it is sunny. The amount of electricity fed in by wind and solar installations thus fluctuates throughout the day and through the seasons, depending on the amount of wind and sunshine.

The electricity market is reacting with increasing flexibility to fluctuating electricity generation from renewable energy sources. For instance, larger consumers are increasingly becoming active on the electricity market, whenever they can strengthen their economic position (demand-side management). We are moving from an electricity system in which flexible power plants generate according to demand to a fully efficient system in which flexible producers, flexible consumers and storage facilities will increasingly respond to the fluctuating supply of wind and solar energy.

Since Germany's total installed generation capacity is considerably greater than its maximum consumption, the electricity supply is guaranteed at all times. Moreover, electricity can be transported across borders in the European interconnected grid, providing an additional level of supply security.

Power plants need electricity too – gross and net generation capacity

When "installed generation capacity" is referred to on the SMARD website, this means net generation capacity. Net generation capacity shows the maximum amount of electricity a power plant can supply once it has subtracted the energy it needs itself (self-supply). Power plants need electricity to operate, eg for coal mills, water pumps, lighting or air conditioning. They meet these needs with their own generation, which is why the statistics distinguish between gross and net Electricity generation. In contrast to the net figure, the gross figure shows the total electrical capacity of a power plant.

The installed generation capacity is shown for each energy source and different market areas over time in the "market data visuals" section. Users can also access this information for a selected time using the market area map in the "German electricity market" section. In addition, details of the power plants can be found in the power plant list  and the power plant map. The generation capacity for each power plant is also specified there.