High voltage – low losses. Is this the beginning of a new era in battery technology?
High voltage – low losses. Is this the beginning of a new era in battery technology?
At FH Dortmund, researchers are pushing the limits of battery technology — testing systems that operate at up to 20 kV
In the laboratories of Fachhochschule Dortmund (FH Dortmund), something is happening that could shake the very foundations of energy storage technology. A research team working under the KV-Batt project is testing a groundbreaking battery system capable of operating at voltages as high as 20 kilovolts — up to 20 times higher than conventional battery storage systems.
If this concept proves successful, the efficiency gains could reach levels once considered impossible.
Why voltage matters
Modern battery systems for the power sector typically operate at voltages around 1 kV. While sufficient for many applications, large-scale installations (for example, 100 MW systems) require extremely high current — in the range of thousands of amperes. As every student of physics knows, according to the formula:
Power (P) = Voltage (U) × Current (I)
if power remains constant, increasing the voltage means lowering the current.
Lower current means lower resistive losses in cables — losses that turn into heat and remain one of the major challenges for energy storage systems today.
“Even the best conductive cables have some resistance. At thousands of amperes, these resistances generate enormous heat losses, which then require costly cooling,” explains Prof. Dr. Stefan Kempen from FH Dortmund. “By increasing voltage tenfold, we reduce current tenfold — and thus dramatically cut energy losses.”
The potential of the new approach
Within the KV-Batt project, researchers have developed a modular battery system designed to operate safely at voltages between 10 and 20 kV. Over the past two years, the system has undergone extensive high-voltage laboratory testing, including resistance to temperature fluctuations, humidity, and dynamic load conditions.
The next step is field testing under real-world conditions. A pilot installation is being built in the municipality of Ense (Sauerland) in cooperation with Ense Werke GmbH, AEG Power Solutions, and WEISSGERBER Engineering. Two battery systems will be installed side by side — a conventional 1 kV system and the innovative 10–20 kV system.
“This will allow us not only to measure differences in energy losses but also to observe how higher voltages affect cell lifespan and how effectively we can monitor and balance the performance of individual modules,”
says Prof. Dr. Martin Kiel, co-developer of the project.
Less heat, lower costs, greater durability
Raising the operating voltage improves energy efficiency, but it also brings additional benefits. Lower current means less heat generated in conductors and connections — reducing or even eliminating the need for complex cooling systems.
The new battery module developed under KV-Batt requires no active cooling and occupies less space than conventional designs. Its construction is nearly maintenance-free.
The system uses advanced, autonomous sensor technology to monitor the operating state of each cell in real time. Each module consists of 27 individual batteries, forming a so-called stack, and several stacks can be combined to easily scale system power and capacity.
A regulatory gap — and an opportunity for a breakthrough
While the technology looks highly promising, it faces one major challenge: the lack of safety and insulation standards for medium-voltage DC systems in the 10–20 kV range.
Clear regulations exist for low-voltage systems (up to 1.5 kV) and very high-voltage transmission (above 100 kV). However, there are no established standards for insulation distances, clearances, or DC circuit breakers in this intermediate range — precisely where the KV-Batt system operates.
“This project could not only deliver technical benefits but also help shape entirely new standards in the field,”
emphasizes Prof. Kempen.
From prototype to European patent
The FH Dortmund research is the result of years of groundwork under the earlier KV-BATT-TECH project, which developed the initial technological foundations. The current phase, KV-BATT-SYST, focuses on real-world implementation with the participation of industrial and municipal partners.
A European patent application is already underway to protect the system’s unique high-voltage module design and monitoring architecture.
If the pilot installation in Ense proves successful, KV-Batt technology could become a milestone in the energy transition. Higher efficiency, lower losses, the absence of cooling requirements, and a compact, modular design could significantly reduce investment costs and boost the reliability of energy storage systems.
Prof. Kiel sums it up succinctly:
“By raising the voltage, we raise the efficiency of the entire system. It’s a simple principle — but on the right scale, it can change the game.”
Source: fh-dortmund.de