Renewable Energy – Solutions for application in the communal energy infrastructure

22 | BIOENERGY
Biogas – stored solar energy to gas
Biogas is produced by fermenting energy crops, slurry, biological waste or similar materials in a fermenter. It
primarily consists of methane and can be used in a similarly flexible way as natural gas – for cooking, heating,
electricity generation and even as a fuel.
Biogas is produced by fermentation from organic
substances, from slurry to grass and biogenic waste. If
local waste materials are used for its production, such
as from agriculture or the food and catering industries,
the added value increases at a local level. Biogas consists
mainly of methane, i.e. the substance that is also
the primary component of natural gas, and is similarly
versatile.
This means that conventional gas-fired power plants,
natural gas-driven cars, heavy goods vehicles or even
ships can also be run on biogas.
One particular advantage of biogas in the course of the
energy transition is its storability. It can effectively
help balance the fluctuating generation of wind and
solar power in the system.
Often, the biogas is used to run local cogeneration
plants – standardised mini power plants that supply
electricity and heat at the same time. This ensures a
particularly efficient use of the energy. Biogas can also
be used for cooking, heating and even as a fuel source
for specially adapted vehicles. What’s more, it is possible
to process biogas into pure methane. This can then
be used in exactly the same way as natural gas and can
also be fed into the natural gas grid and extracted again
elsewhere.
For farms, the technology offers yet another advantage:
The fermentation residues from the fermenter possess
even better properties as fertiliser when compared to
the starting material.