We identify model users in industry, commerce and large residential areas who can flexibly adjust their energy demand to the intermittent feed-in from wind and solar power stations. New flexibility options are also offered by energy integration applications (power, heat, cold, mobility) and in regional power plants, where producers and consumers are closely integrated. We test the use of these flexibility options in order to reduce grid congestion and to optimally exploit the available green power output.
Identifying and characterising flexibility
Within an energy system with a very high share of volatile renewable generation, flexibility becomes more and more important. This especially concerns the user side, as by means of adjustable or, if necessary, switchable loads, surplus energy can be used directly and without loss. Even though many flexibility options have already been described in theory long ago, the identification and characterisation in real conditions and existing processes often still present a challenge. In commerce and industry, too, it is often still necessary to rethink the necessities and possibilities of load flexibilisation.
We identify and characterise model flexibility options as well as the ancillary conditions for the relevant application, such as: which parameters of the processes involved have to be observed? Who or what can control the flexibility at which time? The question of which revenue models can be used to turn flexibility to profit is put aside for the time being. The focus lies on three promising workstreams:
Technical flexibility potentials will only then be activated when a market use can be identified and the regulatory requirements become more conducive to flexibility. In general, there are already various applications for flexibility (balancing power, peak shaving, spot market). Smart marketing should consider all application options and as such maximise the value of the flexibility. In addition to the know-how of the operators of flexibility installations and the marketers / aggregators, non-discriminating, competitive and easily accessible markets are needed.
- Identification of problem areas / obstacles for practical marketing possibilities: such obstacles can consist of difficult market access or a lack of incentive mechanisms for the flexibilisation of power. Given the current framework conditions of the market, the economic value of small to medium flexibility reserves in industry or residential areas can for instance only be increased to a limited extent despite their large potential. The specific legal and regulatory obstacles for the use of flexibility have to be analysed and recommended actions have to be formulated for a further development of the legal and regulatory framework.
- Studying a specific further development of markets: in collaboration with virtual power plants and aggregators, WindNODE specifically works on the marketing of flexibility units, however small, on the balancing power market. In addition, we study the procurement of flexibility on the market as a grid support service in a large-scale field test with the flexibility platform, invoking the ‘experimentation clause’ (SINTEG-V). By doing so, WindNODE provides a tangible and reliable practical contribution to the current legal and regulatory debate on the usefulness and design of so-called ‘smart markets’.
System integration of sector coupling
The view of the electricity industry falls short of the mark for a successful energy transition. Especially in the heat and mobility sector, there is enormous potential for the flexibilisation and decarbonisation of loads. From a technical perspective, this so-called sector coupling is not really new. Nevertheless, it will have a crucial role to play in the system integration of large renewable electricity volumes. Sector coupling concepts face at least as great regulatory and economic challenges as technical development needs. To date, grid and system supporting sector coupling technologies are subject to legal disadvantages on the electricity market (EEG surcharge, grid fees etc.). As regards sector coupling products (especially heat and gas), the ‘green’ aspect of the electricity has not yet been sufficiently taken into account.
We are studying three important fields of sector coupling: Power-to-Heat (PtH) with applications in all orders of magnitude, from decentralised night-storage heaters in the kW range to the use within the Berlin district heating system in the (up to) 100 MW range; Power-to-Cold (PtC) for commercial cooling units, ice storage and for a combined PtH-/PtC installation, as well as controlled charging for electromobility. The central question is always how the load shifting potentials and the functional storage (heat/cold) can be technically deployed as flexibility reserves for the system integration of renewables and can be promoted both in an economic and regulatory sense. In the electromobility sector, we are developing use cases together with specific customers and identifying drivers for the integration of the charging infrastructure, especially in the commercial mobility domain.
- Integration of sector coupling installations to provide flexibility and ancillary services
- Marketing options for sector coupling installations as regional flexibility on the flexibility platform
- Use of sector coupling installations for the system integration of renewable energy in case of an impending cutback in wind turbine output due to grid congestion
Balancing regionalisation and transmission
Transmission systems create flexibility if the load and generation centres of different regions can be interconnected. With the increasing integration of renewable energy from remote locations, grid capacities are more intensively used. During times of high wind, this leads to transmission bottlenecks within the WindNODE region and export limits at the country borders (interconnections). Regional balancing processes can help avoid grid congestion at all levels. So far, the control processes (incl. market design) are hardly designed to reward system load reducing effects. By combining centralised and decentralised regionalisation and transmission solutions, a secure and both economically and systemically efficient supply can be guaranteed.
- Regionalisation at the distribution system level: regional power plants assume responsibility for system compatible feed-in at the distribution system level by proactively coordinating the feed-in from various neighbouring production plants (also using storage units and sector coupling) and connection capacities.
- Regionalisation at the transmission system level: ‘wind in the cities’ means activating load reductions within the control area to avoid congestion (grid surpluses) in the transmission system and at the borders of the control area. In order to organise balancing processes be-tween generation and consumption in a regional context to reduce the load on the system and to use the proven market mechanisms of the energy-only market to this end, the eligible flexibility requires corresponding regional incentives.
Allocation processes should be secure, free of technological preferences and non-discriminatory. The subsidiarity principle can be effective where decentralised solutions offer an economic advantage compared to global energy trade and grid transport (e.g. avoiding the use of limited grid capacities through consumption close to production or higher acceptance by means of demand-oriented local or regional electricity products or balance responsible perimeters).