Munich is working on solutions for the viable city of the future together with numerous partners from business and science.
In an era of rethinking lifestyles in the name of resource conservation and supported by rapid technological advancement, Hybrid Energy Systems are experiencing a strong upsurge. Due to the multitude of possible combinations, hybrid energy systems can deliver highly efficient solutions for energy generation and can guarantee maximum performance.
This offer targets energy providers, private companies, city administrations, households, mobility providers, mechanical engineering companies.
The high-tech networking of different energy sources can guarantee the highest efficiency in energy generation. Due to the combination of central and decentralized storage forms, intelligent and low-loss control of energy consumption can also be achieved.
The objective of such an energy supply network is to achieve a balance between production and consumption. To achieve this, the seamless integration of various technologies linked to the generation, storage and consumption of energy is imperative, offering new niches for innovative solutions.
Hybrid energy systems consist of at least two different energy sources which complement one another. The possible combinations of conventional and renewable energy resources enable an innovative and energy-efficient solution for cities, districts or individual households.
When combining exclusively renewable sources of energy, such as solar or wind energy, hybrid energy systems can deliver 100% renewable energy with the added benefit of improved flexibly and ability to adapt to meet demand.
Due to increasing technical progress facilitating the emergence of new possibilities and innovation in this area, demand for hybrid energy systems has grown considerably. Cities have demonstrated particular interest in these solutions as they present a means of effectively managing supply and demand, improving energy security.
A hybrid energy system is fully automatic and consists of at least one energy processing plant, a control system and a (short-term) energy storage unit for excess generated energy. Due to the closed-loop system, excess energy is stored and the consumption can be controlled.
The Fraunhofer project “HYBRIDE STADTSPEICHER” (Hybrid City-Storage), is a collaboration between Fraunhofer UMSICHT (coordination), Fraunhofer ISE, Fraunhofer IOSB-AST and Fraunhofer ISIT. The objective is take advantage of the enormous potential of cities to store and utilize energy. Cities can play a valuable role mediating the direct balance between energy supply and demand in the local network. Covering both electricity and heat generation, renewable energies are integrated with central and decentralized electrical storage as well as with decentralized generators and loads made available through additional thermal storage.
The challenges for the future of the energy system is achieving a spatio-temporal balance in the context of strongly fluctuating and dispersed consumption and renewable energy production.
This challenge can be met by four complementary technology paths:
In the case of energy storage, small, decentralized battery-based lithium-ion batteries (approx. 1-20 kilowatts) are coupled to larger storage units of approx. 50 kilowatts to 5 megawatts (such as the redox flow technology further developed by Fraunhofer) Photovoltaic (PV) systems.
In terms of conventional network expansion, in addition to the cost-intensive high-voltage direct-current transmission, which is only relevant in the context of long-distance network delivery, regional network capacity expansion focuses on the better use of networks by intelligent regulation and storage.
Controllable consumption focuses mainly on decentralized heat pump systems with high-performance thermal storage.
Planable power generation is facilitated through decentralized heat and power generation plants operated by means of high-capacity thermal storage tanks, which are temporarily operated instead of heaters as usual.
While nearly all technologies will be deployed (mostly in buildings) in the near future, for network operators there is much potential for the utilization of relatively inexpensive storage capacity at city or district level (medium voltage / low voltage, i.e. local power transformer).