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An Interview with Urban Windelen


Energy storage devices are a fundamental element for the energy transition. However, current political framework conditions are limiting their potential development. An interview with Urban Windelen, CEO of the Federal Association of Energy Storage.

According to some studies, energy storage devices are only required if the proportion of renewable energy in the power mixture rises to 60%. Do we still have time to wait a few decades?

The market is more than ready for storage devices, and our energy system absolutely needs them. At the moment, approximately 40% of our energy mixture comes from renewables, and in many regions the use of energy stores is already imperatively necessary. An abundance of wind energy in the north versus low levels of solar power in the south demands smoothly functioning electricity transport to reliably supply the urban areas in southern Germany with power. While it is obvious that we require strong electrical grids for this, networks alone will not solve all of the problems. Energy stores are required for timely balancing of the fluctuating energy supply; otherwise, network bottlenecks and feed-in limiting will run rampant. In the last ten years, the costs for re-dispatching measures increased more than seven-fold. To put an end to the inefficiencies in the current energy system, we should exploit energy stores at an increased rate now, rather than waiting a few decades.

This means that we desperately need the flexibility options that energy stores could provide for the energy system. How cost efficient are energy storage devices?

Energy storage units are like a Swiss army knife: they are a handy tool with a multitude of different possible applications. An average pocket knife may be more expensive than an average table knife; however, it still costs less than a knife, plus scissors, plus all of the other options, that a pocket knife combines into one tool. Energy stores improve the efficiency of the energy system through their multifunctionality – both with regards to costs and also to the time involved. Power-to-gas solutions clearly illustrate the multiple usage potentials: the systems use excess electricity to generate hydrogen and methane, which are in turn used for eMobility and heating, and can also be combusted again for electrical generation.

Where does energy storage technology stand in the current state of development?

Energy storage devices are already market-ready; however, their development is severely hampered by regulatory frameworks. These regulations were developed for the old, centralized power supply system. Across Europe, decentralization in the energy system is both desired and promoted, and we desperately need energy storage devices for a decentralized energy system. Another important driver lies in technical developments in digitalization. WAGO, with their advanced measurement and control technology, is at the forefront in redefining out potential communication and networking technologies. ‘Digitalization’ is a magic word that appears constantly in all political statements. Everyone wants it, but it is only possible with storage technology. Energy storage devices are ripe for use; the politicians (simply) have to allow it.

A core sector in the energy transition is eMobility. What role can storage technology play in this field?

Storage technology plays a very important role in eMobility. The disputes tend to focus on how we can expand eMobility as quickly as possible. Everyone does indeed agree that we need a suitable charging infrastructure in order to bring eVehicles to the streets. And for that, we need storage devices. The design of the charging infrastructure absolutely has to be adapted to “prosumer” behavior, that is, the behavior of consumers who are also producers in an intelligent energy system. eVehicles are virtually mobile storage devices; they can be charged and discharged in a regulated way. And charging stations, like large power storage devices, are suited for multiple uses. “Charging collection points” could function, in principle, on the balancing energy market. Aldi-Süd has demonstrated a solution oriented toward the future. It is using photovoltaic systems in some of its stores and has linked them, using storage devices, to charging stations for eVehicles in their parking lots. The current for the charging stations comes from the solar power produced on site, which is easily stored during excess production. Aldi saves on electrical costs, particularly during peak load times. In addition, the charging infrastructure of the future must enable rapid charging. Who wants to wait for a whole day, or longer, at the charging station just to be able to continue driving? Energy storage devices are finding use here as well: in order to provide a lot of current at once, it makes sense to incorporate buffer stores into rapid charging stations.

What are the particular challenges facing the energy storage sector?

Regulations are the greatest impediment. Although the market is mature, politicians are preventing storage devices from participating. Storage devices are positioned as both producers and consumers. When electricity is stored, that is, drawn down from the grid, then taxes and duties are owed for network consumption. When electricity is discharged, then the kilowatts are classified as newly generated, for which taxes and duties are owed again. Because storage units have to pay taxes twice, many business models fail. To change this, storage devices should be positioned as legal nullities. An energy store is, from a technical viewpoint, a delaying element that functions in the grid by restoring that which it previously removed. Therefore, storage devices should be considered as the fourth pillar in the energy system, along with production, transportation, and consumption.

Mr. Windelen, thank you for the conversation.