Storing renewable energies efficiently and making them usable - with eFuels
Storing renewable energies efficiently and making them usable - with eFuels
Table of contents
Challenge: energy production and storage
Renewable sources such as the sun and wind supply enormous amounts of energy. Yet this potential often goes unused and is lost entirely because production and demand frequently do not coincide: while sunshine and strong winds produce a surplus during the day, this energy is missing on still nights or cloudy days. As a result, a shortage of renewable energy is particularly noticeable during the winter months.
Another problem: electricity is not easy to store. Unlike water or fossil fuels, electricity requires complex technologies to make it available for later use.
A large proportion of the energy supplied by the sun and wind is lost unused due to a lack of practicable storage solutions. This loss is not just a missed opportunity, but an enormous waste of valuable resources.
eFuels as a means of storing renewable energy.
- Long-term storage: eFuels remain stable and usable for months or even years.
- Easy transport: Like petrol or diesel, eFuels can be distributed through existing infrastructure, including filling stations, pipelines and tankers.
- Flexible use: They can be used in vehicles, heating systems, power plants or industry without technical modifications to existing equipment or networks.
eFuels are being discussed as a possible technological option for storing and transporting electrical energy in the form of chemical energy carriers. These synthetic fuels store surplus energy and make it available for flexible use at any time and in any place.
eFuels create a direct connection between the electricity sector and other energy sectors.
Surplus energy is converted into chemical energy carriers that can be used in transport, heating and industry.
Power generation
Surplus electricity from wind and solar power serves as the basis.
Electrolysis
Water is split into hydrogen and oxygen - an important step in storing energy.
CO2 capture
CO2 is extracted from the atmosphere or industrial waste gases.
Synthesis
Hydrogen and CO2 are combined to create liquid fuels such as eDiesel or eKerosene.
eFuels and the role of sector coupling
The Fraunhofer Institute for Energy Economics and Energy System Technology (Fraunhofer IEE) emphasizes that sector coupling is a key element in the transformation of the energy system from fossil fuels to renewable energies. It makes it possible to introduce flexibility into the energy system and support the further expansion of renewable energies, as wind energy and photovoltaic systems generate electricity according to weather conditions rather than demand(Fraunhofer IEE, 2024).
Conclusion: eFuels as chemical energy carriers
Using renewable energy requires not only expansion of generation capacity but also solutions for storage, transport and connecting different energy sectors. Sector coupling can convert electrical energy into other forms of energy for use in different applications.
Properties of eFuels as chemical energy carriers
Long-term storage
During the production of eFuels, electrical energy is converted into chemical energy carriers through several process steps. These can be stored for extended periods and used in different applications when needed.
Understanding the greenhouse gas balance
The greenhouse gas balance of eFuels depends, among other things, on the source of the electricity used, the carbon source, production conditions, transport and subsequent use.
Use of existing infrastructure
Depending on the fuel specification and application, parts of existing storage, transport and refuelling infrastructure can be used for eFuels. Whether technical modifications are necessary depends on the infrastructure and intended use.
eFuels can enable electrical energy to be stored and transported in the form of chemical energy carriers. The energy density of liquid fuels is one reason why they are being discussed in connection with long-term storage, transport and sector coupling.
However, comparisons with other storage technologies must consider the application and the entire process chain. This includes, for example, the energy required for conversion, potential conversion losses, production capacity requirements, raw material demand and existing infrastructure. Battery storage and chemical energy carriers can perform different functions within the energy system.
Frequently asked questions (FAQ) - eFuels and their role in energy storage
Renewable energy sources such as the sun and wind generate electricity depending on the weather, time of day and season. Surpluses often occur when energy demand is low, while at other times there is a shortage. Without suitable storage technologies, these surpluses are lost and cannot be used when they are urgently needed.
Electricity cannot be stored in a tank like water. Batteries and pumped-storage power plants offer only short-term storage and reach their limits when dealing with seasonal fluctuations.
eFuels store surplus electricity from renewable energies by converting it into liquid/gaseous chemical energy carriers. These can be stored for the long term, transported and used across sectors – for example in mobility, industry or the heating sector.
Yes, eFuels are an excellent addition for long-term storage. While batteries are efficient for short-term applications, eFuels allow large amounts of energy to be stored for months or even years.
eFuels score points for their high energy density, long-term stability and versatility in transportation and use.
eFuels can be used in existing infrastructure such as filling stations, pipelines and storage systems. This eliminates the high investments required for new storage and distribution networks, as is the case with batteries.
Sector coupling refers to the integration of different energy sectors such as electricity, heat and mobility. eFuels play a central role here, as they convert energy from the electricity sector into chemical fuels that can be used in other sectors. This creates a bridge between electricity production and consumption in areas such as transportation and industry.
Renewable energies are often produced depending on the weather and do not always match direct consumption. Sector coupling converts surplus electricity into chemical fuels that can be used in areas that cannot be electrified – for example in heavy goods transport or in high-temperature industry.
Thanks to the ability to efficiently store surplus electricity from renewable sources, eFuels reduce the need to switch off solar and wind power plants when there is excess production. This increases the economic efficiency and stability of the renewable energy system. If renewable energy can be stored in large quantities, the production infrastructure (e.g. wind turbines/PV plants) can be kept to a reasonable minimum and thus also the negative environmental impact and costs that arise.
References:
- Ariadne analysis, Kopernikus project Ariadne, Potsdam Institute for Climate Impact Research (PIK), funded by the Federal Ministry of Education and Research, February 2024
- Moore, A. (2024). Huge advances in energy storage are needed – are batteries the solution?, retrieved 26.11.2024, from https://andrewmoorescientist.com/1-speicherbare-energie/
- Fraunhofer IEE (2024). Sector coupling: hydrogen, heating networks, e-mobility. retrieved on 26.11.2024, from https://www.iee.fraunhofer.de/de/leitthemen/sektorenkopplung.html
Newsletter registration
Notes on data protection
Our free newsletter informs you regularly by e-mail about new products and special promotions. The data you enter here will only be used to personalize the newsletter and will not be passed on to third parties. You can unsubscribe from the newsletter at any time or revoke your consent at any time by sending an e-mail to . Your data will be deleted within 2 months after you stop receiving the newsletter, provided that there are no statutory retention obligations to the contrary. By submitting the data you have entered, you consent to the data processing and confirm our privacy policy.
We will be happy to answer all your questions.