AEG Power Solutions, a supplier of grid equipment and uninterruptible power supply systems, has developed a new platform to reduce the cost of battery-based energy storage.
Because the battery is the most expensive component in an energy storage system, reducing the size of the battery remains the most effective way to bring down the cost.
AEG PS, headquartered in the Netherlands but with operations in Germany, has developed a platform that combines battery storage with power-to-heat technology.
The combined system can be deployed by any entity that uses thermal processes in its facilities, including local heat networks in combination with electrical distribution networks.
The company is also targeting the commercial and industrial segment, where some companies and manufacturers have demand for electricity and processing heat. The battery can generate revenues by provide frequency control services as well as provide other benefits, such as back-up.
Stefan Kempen, who is product manager for grid and storage at AEG PS, says: “There is no support or grants for energy storage, which I am fine with, as it means we will see healthy, stable growth, rather than the boom and bust cycles of the solar PV market.
“Since we first entered the energy storage industry a few years ago, battery costs have come down considerably and will continue to do so. However, we found we had to do something to bring down the cost to help bridge that gap.”
For a stand-alone battery storage system to provide grid frequency regulation, the battery has to maintain a state-of-charge of 50%, to both absorb and inject energy into the grid.
By combining energy storage with a power-to-heat system the battery can operate at 100% state-of-charge, using all available capacity. Any electricity the system absorbs from the grid goes straight to powering the heating/thermal system, as opposed to charging the battery.
As the battery is about 70% of the whole system’s capital expenditure, when the battery size is halved, the overall energy storage system cost comes down significantly.
AEG PS has developed a dedicated battery storage plus power-to-heat platform, where the battery’s power control system (PCS), including the medium voltage connection, can also control the power of the heater. “So far, we are the only company that has come up with something like this,” says Kempen.
The platform covers aspects such as the how the components, including the battery storage, the power-to-heat and power conversion hardware is all connected up, as well as the software controls required to operate the system.
The key components include the energy management system — the brains of the platform — the power electronics, the medium voltage connection equipment, including transformer and switchgear, communications, the battery system and the power-to-heat system. This last piece of equipment is supplied by German company Schniewindt.
Though AEG PS has only recently finalized the development of the system and begun promoting it, there are already customers showing strong interest in the offering.
“For utilities, they can install the system on their existing power plant sites, or on those that they are retiring, where there is everything they need to integrate and connect the system into the grid,” Kempen says.