Sector integration combines the power, heat and gas networks as well as the mobility sector. It will be a key technology for the energy transition of Germany on the way to achieving its target of climate neutrality.
Integrated energy; © Foto: DVGW, Roland Horn
Essential for a rapid energy transition
Integration is to ensure effective use of synergies by linking and optimizing the three energy sectors of power, heat and mobility using natural gas as a fuel. The objective is to use energy at the right place and the right time. The synergy effects can compensate for fluctuations in renewable energy sources. Sector integration is therefore the key technology for the energy transition.
Sector integration using gas is especially well-suited for rapid implementation of the energy transition. Large quantities of energy can already be transported and stored using existing gas network infrastructure. Via power to gas, this storage capacity can also be tapped for renewable energies. The gas produced in this way is available for heat and power generation, for the mobility sector and for industrial processes (e.g. in the chemical industry). Sector integration will be essential for future energy systems supplied solely from renewable sources. The overall objective of integrating individual energy and consumption sectors is the comprehensive decarbonization of the world economy.
Power to valuables means that excess power is used by industry in a targeted way for the synthesis of chemical products, compressed air production, the melting of metals, surface treatment processes, etc.
The process for producing liquid fuels from excess power via electrolysis/hydrogen production and the synthesis of usable feedstocks (e.g. methanol) is called “power to liquids”. This process can also be used for producing fuels consisting of synthetic hydrocarbons (dimethyl esters, kerosene, etc.).
Energy integration refers to the combination of power, heat and gas networks as well as the mobility sector. The power to X technologies allow electric power to be transferred to the other sectors, exploiting synergy effects between the sectors.
Structural integration refers to the combination of energy sectors (power, heat and gas) with consumption sectors (domestic, commercial, industrial and traffic sectors). These consumption sectors are characterized by customers with different demand profiles and sizes.
In power to gas technology, gas fuels are produced by electrolysis (the splitting of water into hydrogen and oxygen) using (excess) power from renewable sources. This may be followed by methanation (the production of renewable natural gas by adding carbon atoms), which may provide a key integration element between power and gas infrastructure with the aim of creating additional flexibility.
Excess heat may be used on the heat energy market to supply simple heating elements in district heating systems.
In power to mobility technology, excess power is used for charging the batteries of electric vehicles. In theory, the batteries of electric vehicles could be used for power storage and could feed electric power back to the grid. Alternatively, hydrogen and methane from power to gas processes may be used for CNG and LNG mobility.
The cogeneration process allows gas from power-to-gas plants stored in gas storage facilities to be used for the highly efficient combined generation of electric power and heat.
Small power stations located near to customers generate power for customers’ own needs. The heat which is also produced can be used very efficiently for space heating purposes.
In future, the principle of the fuel cell will be used to convert stored hydrogen from the power to gas process into power in a high-efficiency process.
Combined cycle power stations equipped with gas and steam turbines are the most efficient large power stations, reaching an efficiency of almost 60%. They can also supply heat.
With biomethane treatment, biogas is fed to the natural gas system, where it replaces the same quantity of natural gas.
Excess heat may be used on the heat energy market to supply simple heating elements in district heating systems.
In power to mobility technology, excess power is used for charging the batteries of electric vehicles. In theory, the batteries of electric vehicles could be used for power storage and could feed electric power back to the grid. Alternatively, hydrogen and methane from power to gas processes may be used for CNG and LNG mobility.