Renewable Energy – Solutions for application in the communal energy infrastructure

6 | INTRODUCTION TO THE “ENERGY TRANSITION”
The Energy Transition
Since industrialisation, the consumption of fossil fuels and raw materials has grown steadily. These still cover
the majority of global energy demand. However, the share of renewable energy and energy efficiency in global
investments in the energy sector is steadily increasing and has remained more stable than investments in
conventional energy, even during the Corona crisis. The transition from conventional energy sources to renewable
and sustainable forms of energy is occurring across all sectors, on a global scale.
Electricity
In 2018, the EU member states obtained around 32 per
cent of their electricity from renewable sources. Climate
protection targets and government funding are only one
reason for this. The other is tangible economic benefits.
The cost of wind and solar energy has fallen so rapidly
over the last twenty years that in many cases, they
are cheaper than fossil energy forms. At the turn of
the millennium, the generation of one kilowatt hour of
solar electricity in Germany cost around 50 cents; today
it is about a tenth of that.
An increasing number of companies are concluding direct
electricity supply contracts with solar system operators
– without government subsidies. Wind power generation
is also growing immensely. In 1997, global wind power
capacity was 7.5 gigawatts; in 2018, it was 564 gigawatts.
Onshore wind farms, in particular, are among the cheapest
forms of electricity generation today. Offshore wind
(wind farms at sea) is somewhat more expensive because
of the special conditions and requirements, but delivers
energy with particular consistency.
The fluctuating renewable energy sources (wind and
solar) are supplemented by controllable forms of renewable
energy – such as bioenergy and hydropower,
and by modern energy storage systems. Today, it is
mainly batteries, but in the future it will increasingly
be renewable energy carriers such as hydrogen.
Another positive effect of the Energy Transition is the
high level of regional added value. Instead of simply importing
fossil raw materials, investments flow into local
economies. In Germany alone, several hundred thousand
jobs have been created in the green power sector.
Building
Much remains to be done in the building sector, which
accounts for about 40% of the EU’s energy demand.
Depending on the climate zone, this includes, above all,
a considerable amount of energy for heating or cooling.
In 2018, the EU decided (in the “energy performance
of buildings directive”) that all member states must
define a standard for new buildings from 2020 that sets
the energy requirement at almost zero. In technical
terms, it has already been possible for years for buildings
to generate more energy than they consume. The
“Solar Settlement at Schlierberg” in Freiburg (Germany),
the residential tower “Elithis Danube” in Strasbourg
(France), the supermarket of the Migros chain
in Zuzwil (Switzerland) and Solar-5 in Vladivostok are
just a few of many examples. Member states must also
present a plan for the reno vation of existing buildings,
as demanded by the EU.
In order for the energy transition in the building sector
to succeed, energy demand must be minimised through
measures such as efficiency standards, highly effective
insulation, and others. At the same time, the demand
must be met with renewable sources where possible.
This can be done, for example, with a heat pump
powered by electricity from a green electricity provider,
or by generating heat or electricity with a solar system
directly on the building. With good planning and
a long-term time horizon, highly efficient houses save
their occupants a lot of money.