Electricity from renewable energies


Definition: What is renewable electricity?

Renewable or regenerative energies are energy sources that are either infinitely available or can grow again within a (comparatively) short time.

These energy sources are thus in contrast to fossil fuels such as oil, natural gas and coal. In addition to hydro, solar and wind energy, renewable energy sources also include biomass and geothermal energy. 1

Share of electricity from renewable energies in total consumption

How much electricity comes from renewable energies? The share of electricity from renewable energies in the general power supply is rising continuously. In 2000, for example, it was still around six percent; by 2020, it was already around 45 percent.

The target for 2020 was 35 percent electricity from renewable sources, which significantly exceeded the forecasts of the Renewable Energy Sources Act (EEG). 2 In addition, the share of electricity generated from renewable energies exceeded the share of electricity temporarily exceeded the share of electricity from fossil fuels for the first time in 2020. Above-average solar radiation, as well as good wind conditions, ensured increased electricity generation from wind and photovoltaic systems. 3

What are the options for storing renewable electricity?

Several storage technologies are available for storing electricity from renewable sources. A distinction is made between the following types of storage:

Battery storage
Batteries are electrochemical storage devices. While lead-acid batteries were the main type used in the past, lithium-ion batteries are now being used more frequently. Their advantage is that they have a very high efficiency of around 85 percent. However, batteries are relatively expensive for large-scale applications for electricity from renewable energies.

Pumped storage
Pumped storage is currently the only form of energy storage that can be used on a significant scale. In pumped storage power plants, energy is pumped into a higher basin where it is stored. It is only released again when a generator is connected and the energy is discharged via a turbine.

Compressed air storage
This technology uses the process of compression: excess electricity is used to force air into underground gas caverns. When needed, the compressed air is released through a turbine, generating electricity.

Power-to-Gas
In power-to-gas plants, water is converted into hydrogen and, if desired, methane through the use of electricity. The advantage is that some of the hydrogen (and the methane without restriction) can be fed into the existing natural gas grid and stored. Once fed in, the gases can be converted back into electricity or used for other purposes. This technology is currently very expensive. 4

However, power-to-gas is already being used in fuel cell technology, for example, hydrogen fuel cells and direct methanol fuel cells eingesetzt. 5

What are the benefits of renewable electricity?

Electricity from renewable sources has numerous benefits, but the most important is that electricity from renewable sources can reduce greenhouse gases and slow climate change.

The reason for this is that, unlike oil, coal and natural gas, electricity from renewable sources produces hardly any emissions. In addition, unlike fossil fuels, energy sources such as the sun and wind are available in unlimited quantities.

If energy from renewable sources is produced and used locally, the costs of long-distance transportation can be saved. Another advantage of local production is the strengthening of the regional economy.

Electricity from renewable energies also secures the power supply within a country and makes it less dependent on countries that have a lot of fossil fuels. In addition, the dangers posed by nuclear power plants, for example, decrease with a larger share of electricity from renewable sources 6

Outlook: What does the future hold for renewable power?

The forecast for electricity from renewable energies is good, and the share of electricity consumption continues to rise. An important topic for energy supply in Germany in the future will continue to be the possibilities of energy storage. This is because the storage of electricity from renewable energies is necessary, but today it is mostly still too expensive or not technically mature. A great deal of research and development will be necessary in the future to reduce costs in this area. 4

What else should you know about renewable electricity?

In addition to the areas of electricity and heat, renewable energies are also playing an increasingly important role in the transport sector. As a result of increasing electromobility, for example, electricity from renewable energies is being used more and more frequently in transport.

More and more German and foreign manufacturers are launching electric vehicle models on the market. For these to be able to drive in an environmentally friendly manner, electricity from renewable energies and the corresponding storage technology are required. Other areas where various research and development activities are still needed include drive technology and battery research, the fields of "connected cars" and digitization, and smart electricity billing at charging stations.6

Conclusion

Electricity from renewable sources is on the rise in Germany – as evidenced by the share of electricity from renewable sources in total energy consumption alone. Accordingly, almost half of our electricity comes from renewable sources. This is not only an advantage in terms of environmental protection, but also makes Germany politically and economically less dependent on countries such as Russia or Norway.