Multi-domain energy system

In a modern society, energy demand is increasingly covered by renewable and distributed resources. Wind and solar power are emerging as the most economical options for substituting fossil fuels in all parts of the energy system. The renewable electricity can be converted to heat, gas or used for transport in electric vehicles.

This will connect the different parts of the energy system and require coordinated planning and operation. Due to the variability of renewables, the energy system requires additional operational flexibility in order to balance energy production and demand and to ensure the secure operation of the system.

One largely untapped source of such flexibility is the coordinated operation of energy infrastructures in different domains, in particular the electricity, heat, gas and transport sectors. If sectoral differences in energy demand patterns, inherent time constants, storage possibilities, market dynamics and regulatory regimes can be exploited, the different domains can support each other.
Realizing this potential will require two main changes in the energy system: An increasing number of energy conversion units which can transfer energy between sectors, and coordination at the infrastructure level, i.e. an integrated planning process and strong coordination during operation.

For example, large or decentralized heat pumps can convert electrical power to heat in the district heating system. Their operation can be optimized to provide flexibility either to the electricity system (e.g. to contribute to frequency control) or to the district heating system (e.g. to locally mitigate demand peaks, therefore reducing the dimensioning requirements of the system). Both cases make use of the inherent energy storage capacity of the hot water in pipes and tanks.

Likewise, the electricity and gas systems can be interconnected using power-to-gas (P2G) technology which produces hydrogen or methane from electricity. The gas system can serve as a long-term buffer for the electricity system due to its large built-in storage facilities. The gas can be converted back to electricity on demand or used directly. Additionally, the production of hydrogen can be combined with other processes to produce fuels or other products (power-to-X).

Electrification of transportation holds a large potential for reducing the emissions of GHG. Smart charging and vehicle-grid integration (VGI) of electric vehicles can provide large amounts of flexibility to the electricity system at the system and local levels. It can be combined with other similar sources of flexibility including electrification of heavy-duty transportation, battery electric energy storage (BESS) or smart data centers.

The research of CEE includes development of control methods and control infrastructures which contribute to sector coupling by coordinating the operation of energy resources, storage systems, energy distribution infrastructures and demand response and novel simulation and system testing methods for performance verification. Furthermore, CEE investigates new types of integrated energy markets as well as design and planning methods that covers technical coordinated control and markets operations.

CEEs research is supported by the unique PowerlabDK facilities such as the multi-domain lab SYSLAB and the living labs in EnergyLab Nordhavn and on Bornholm for experimental investigation and testing. Additionally, advanced system simulation that encompasses physical modelling, user behavior and market modelling is combined with increased system knowledge (data collection) to investigate the large scale impact of integrated multi-domain energy systems.