The European energy system will experience important changes in the near future, in particular due to the targets set for renewable energy integration, reduction of greenhouse gas emissions and energy efficiency. Other evolutions like the electrification of energy end-uses (e.g., development of electric vehicles, electrification of heating) will also have an impact. Different studies show that there is a growing need for more flexibility and a more active involvement of all the stakeholders at all levels (from small consumers to pan-European networks) to ensure the efficient and reliable operation of the electricity system. Developing and exploiting synergies between different energy carriers offers a means to provide the required flexibility.
By optimizing the synergies between electricity, gas, heating and cooling sectors, so-called multi-energy systems (MES) can provide flexibility services to the electricity system, supporting cost-effective RES integration and enhancing security of supply. The enhanced integration of different energy networks brings increased circularity to the energy system, through cogeneration, power-to-x technologies, renewable gases and the recovery of waste heat. The Horizon 2020 project MAGNITUDE addresses the challenge to bring under a common framework, technical solutions, market design and business models, to maximise flexibility provision.
Combinations providing larger flexibilities
Flexibility is defined as the ability of the system to maintain continuous service in the face of rapid and large swings in supply and/or demand, of network topology changes and mismatch between supply and demand. A large amount of efforts have been focused on the flexibility of different technologies; and the development of innovative technical solutions relies on a deeper understanding of the technological and operational constraints (and associated rebound effects) to the exploitation of flexibility potential deriving from the coupling of electricity, heat, and gas networks and production technologies. Multi-energy coupling technologies and their combinations have potential to provide larger flexibilities through synergies with heat and gas networks.
Market-optimised MES behaviour
MES behaviour can be optimised towards the identified electricity market services. This optimisation enables the evaluation of the benefits, arising to the MES-operator and possibly to the (national/regional) electricity system operator, by the quantification of the remuneration/cost-reduction and the amount of flexibility made available. Aggregation can increase the ability of a MES-operator to provide flexibility. When smaller systems are aggregated, the bids are subject to less restrictive constraints than balancing market bids.
The backbone for an integrated energy system
District heating and cooling networks provide flexibility through the means of technologies which are both already technically and commercially available. These systems are the ideal backbone for a highly integrated energy system. For systems based on CHP production of electricity and heat, variation of the electricity production can be used to provide flexibility; however, the heat supply for the district heating network is a determining factor regarding replicability potential. For low-temperature networks, load shifting through heat pumps can provide flexibility. Cost-efficient heat pump integration represents a key technical challenge. Energy integration through DHC system enables the integration of variable renewable electricity and maximises the recovery and utilisation of locally-available waste heat sources from both industry and unconventional sources. Modern low-temperature heat network systems should be promoted, as they can connect local demand with renewable and waste energy sources, as well as the wider electric and gas grid – contributing to the optimisation of supply and demand across energy carriers.