Quarter solutions

Quarter solutions enable individual city districts or large consumers (e.g. shopping centres) to achieve a certain degree of self-sufficiency despite being integrated into an electricity distribution network. The main focus here is on an energy-efficient and climate-friendly coupling of heat, electricity and mobility with the integration of state-of-the-art communication technologies. The potential is great, because a large part of humanity lives in urban areas.

References

 


Relevance of this field of application

In geography, the term "quarter" refers to an urban district or area that can be distinguished from its surroundings based on the socio-economic similarity of its inhabitants.1 In the present context, it is also about subspaces of urban settlement areas. However, quarters are defined here less by the characteristics of the residents than by the fact that a common, local energy supply solution ("quarter solution") can be realised. In this sense, a shopping centre, for example, can also be described as a neighbourhood. In contrast to isolated solutions that aim for complete self-sufficiency, quarter solutions are basically integrated into an electricity distribution network (usually of a single network operator).

Quarter solutions bundle the needs of many stakeholders in order to optimise their electricity supply in terms of environmental protection and resource conservation, economic efficiency and security of supply. The background to this is that joint optimisation projects are generally more cost-effective to realise than the sum of individual projects due to economies of scale and synergy effects. Quarter solutions have a spatial and actor scope that makes joint optimisation manageable at the same time. Compared to isolated solutions, they have the advantage that supply security can be improved and investment costs further reduced.

 

1 Spektrum (2020): Lexikon der Geographie – Quartier.
Link ↗ (Zugriff am 15.01.2021).

Generation, distribution and consumption must be coordinated within the quarter and in interaction with the distribution grid. This also includes the sector coupling of electricity, heat and mobility: electricity surpluses can, for example, be used flexibly for mobility via hydrogen production (power to gas) or for heat generation (power to heat).2

2 Deutsche Energieagentur (dena) (2018): dena-Leitstudie Integrierte Energiewende. Impulse für die Gestaltung des Energiesystems bis 2050.
Link ↗ (Zugriff am 18.01.2021).


Use of battery storage

A quarter solution consists of a diverse mix of generators, consumers and energy storage systems. The task of battery storage is firstly to ensure a balance between generation and consumption within the quarter as well as a self-consumption-optimised power supply for the quarter. Secondly, battery storage can take over grid functions for the distribution grid in which the quarter is embedded.

Elements that a quarter solution can include are generation plants (photovoltaics, wind power, hydropower, etc.) and, on the consumer side, building infrastructure (lifts, lighting, building management, etc.), gastronomy (peak load), food retail (cold storage), data centres (UPS requirements), parking space management for electric mobility (charging stations) and the power supply for private households, among others. The sector coupling of heat and electricity results primarily from heat-led combined heat and power plants in the winter months, whose surplus electricity can be temporarily stored in batteries.


Performance requirements

Battery storage in quarter solutions must meet high safety requirements, as is generally the case in residential areas: Fire and explosion hazards should be excluded as far as possible. Cycle stability is also a key requirement: If the battery storage systems used, as well as other (e.g. generation) elements of the neighbourhood solution, promise lifetimes of several decades, this pays off in terms of investment security - especially important for high total investment volumes.3

Some applications within neighbourhood solutions rely on high charging or discharging currents (such as car charging stations). In view of this, the fast-charging capability of the batteries is also an important desideratum. Finally, environmental compatibility should be mentioned, as quarter solutions often pay special attention to a sustainability-oriented energy supply. Resource efficiency in production and operation are therefore equally important requirements that the battery storage systems used should meet.

 

3 Stadt Luckenwalde (2013): Integriertes energetisches Quartierskonzept „Dahmer Straße".
Link ↗ (Zugriff am 15.01.2021).


Market outlook

In Germany alone, electricity demand in households amounted to 129 TWh (25.1 % of total electricity demand) in 2018, and that for services, trade and commerce to 145 TWh (28.3 %).4 In view of the fact that around 80% of the urban population of no less than 61 million inhabitants lived in 665 cities with more than 20,000 inhabitants at the end of 2019, quarter solutions have great growth potential.5 Another approach to the question of market volume is offered by looking at the number of shopping centres: by the end of 2017, there were 479 of them in Germany.6

Overall, recent studies indicate that the use of battery storage in quarter solutions can be more efficient compared to the use at individual household level: The same effect can be achieved with 65% of the capacity as with 100% home storage. The feed-in to the distribution grid can also be significantly lower.7

Overall, the need for battery storage in quarter solutions depends on which specific objectives the respective quarter solution is to fulfil.

 

4 Umweltbundesamt (2020): Energieverbrauch nach Energieträgern und Sektoren
Link ↗ (Zugriff am 15.01.21).

5 Destatis (2020): Städte (Alle Gemeinden mit Stadtrecht) nach Fläche, Bevölkerung und Bevölkerungsdichte am 31.12.2019.
Link ↗ (Zugriff am 15.01.2021).

6 EHI (2017): Entwicklung der Anzahl der Shopping-Center in Deutschland 1965 bis 2017.
Link ↗ (Zugriff am 15.01.2021).

7 Barbour, Edward; Parra, David; Zeyad Awwad; Gonzáleza, Marta C. (2018): Community energy storage: A smart choice for the smart grid? Applied Energy. Volume 212.
Link ↗ (Zugriff am 15.01.2021).