Due to the increasing usage of renewable energy sources like photovoltaic (PV) systems in the private sector and their fluctuations in production, energy management systems (EMS) are becoming more and more important. As such system use the produced energy as efficiently as possible, they also have an...

With an increasing share of electricity from renewable energy sources in the German energy market, storage systems are needed to close the gap between production and demand. The thermochemical storage system based on the reversible reaction of CaO and Ca(OH)2 is one of the most promising approaches for...

Several attempts have been made to define and measure performance parameters of photovoltaic home storage systems. Ideally, performance parameters are accepted by the scientific community as well as by manufacturers, test laboratories and customers. The German industry association for energy storage...

Owing to its high energy density, Xylitol is a very promising Phase Change Material (PCM) for low temperature applications (< 100°C). However, it presents a high and persistent supercooling that inhibits the latent heat restitution during thermal discharges. Bubbling in the supercooled PCM is known...

Large-scale thermal energy storages (TES) are advantageous to bridge the seasonal gap between heat demand and availability of renewables. However, the high investment costs associated with large-scale TES is still seen as a major barrier. Among others, challenges are space availability and the presence...

In an international context (e.g. Germany, Denmark), the integration of long-term thermal energy storage (TES) into block heating systems already exists. Yet, the so-called pit TES cannot be easily applied to central European district heating (DH) systems because of the varying heat demand, temperature...

Large-scale thermal energy storage (TES) represents a key component in renewables-based district heating (DH) networks. However, the storage of water at high temperature (< 100 °C) for long periods can lead to a significant amount of thermal losses to the surroundings and to unwanted increase of groundwater...

Large-scale seasonal thermal energy storage (STES) substantially facilitates a full exploitation of the local renewable energy sources (e.g. geothermal, solar, waste heat) potential in renewables-based district heating systems in order to mitigate CO2 emissions and the climate change. Large-scale seasonal...

High temperature thermal energy storage units can provide the flexibility required, by storing the excess energy in the form of heat and suppling it back either into the electric grid or as heat to any energy intense industrial process. DTU Energy has constructed a vertical flow high temperature thermal...

One of the main concerns in extending variable renewable energy (VRE) is the electric grid stability due to the sources’ volatility. Germany is introducing a new auction mechanism within the German Renewable Energy Sources Act called “Innovationsausschreibung” (innovation tender) to grid- and system-supporting...

The ongoing process of thermochemical material development for improved thermal storage applications relies on flexible material characterization in terms of storage capacity, mechanical stability and cycling durability. This work purposes a time-efficient thermogravimetric method and the corresponding...

One essential part in the simulation of electrochemical storage systems like redox flow batteries is the voltage on cell level. In this study, a model is derived for the open circuit voltage and the overpotentials of an all Vanadium system, based on the operation data of three commercial batteries over...

A promising process to store hydrogen is the thermochemical storage based on the repeated reduction and oxidation (redox) of iron oxide or iron. This storage process is an intermittent, two-phase reaction, which takes place under atmospheric pressure in a hydrogen atmosphere during reduction (charging)...

Renewable Energy Sources naturally deliver energy intermittently, causing fluctuations in energy supply. The energy is therefore also not provided corresponding to the actual need, but according to the availability. Hence, the demand for energy storage is rising with the increasing utilization of renewable...

Battery energy storages play an important role in the energy transition toward an energy system based on renewable resources. Today, batteries on a household and community level in Germany are primarily used to increase consumption of self-produced electricity. However, batteries used solely for increasing...

Using findings from a survey of 350 participants, we answer the question to what extent the trends towards more digitalisation and environmental awareness could create a market for decentralized hydrogen applications. The results show that while energy experts are sceptical towards the benefit of decentralized...

Techno-economic analysis that allocate costs to the energy flows of energy systems are helpful to understand the formation of costs within processes and to increase the cost efficiency. For the economic evaluation, the usefulness or quality of the energy is of great importance. In exergy-based methods,...

Lithium-ion batteries can still be used in many applications after removal from their first use in electric vehicles, e.g. as a storage media in photovoltaic systems and for grid support. Therefore, there is a great need to develop reliable methodologies and tools to characterize the expected performance...