„Active peak load management in conjunction with UPS functionality ensures technical and financial stability.“
Head of Office East, Germany
Mr Metzig has completed the planning & implementation of a li-on battery storage system (320 kVA / 300 kWh) with UPS capability for an industry customer, specifically: a global automotive supplier with several sites in Germany.
PN: Mr Metzig, before we specifically talk about your project, could you tell us something about the general market situation concerning storage systems with UPS capability?
Metzig: Given the challenges which companies face in connection with the energy transition, there is currently very keen interest in UPS storage systems. Our customers are aware of the advantages of a hybrid system which enhances safety for sensitive consumers and which – in parallel – provides buffer storage of one’s own generated power, so that it can be made available on a flexible basis.
And the considerations with regard to reducing energy costs – for example by reducing peak loads – are also significant when it comes to the rapid charging of electric vehicles.
We are currently finding that many companies are taking the crisis as the ideal time to set themselves up to meet the future. In most cases, this will include establishing an environmentally-friendly power supply system, typically one which is based on a storage system with UPS capability.
PN: Where you refer to considerations: what was the leading motivation, with specific reference to this automotive supplier?
Metzig: The answers to that question are to be found in a project entitled “Energy storage systems for managing peak loads (peak shaving) to adhere to the 7000-hour rule”. By definition, the operating hours count, which can be described as the quotient derived from annual energy consumption (> 10 GWh) and the highest load peak which occurs in the integral of 15 minutes, is greater than 7000 hours. Compliance with that rule is the prerequisite for achieving an individual network charge corresponding to “Strom NEV” – the electricity grid charges regulations (refer §19, paragraph 2) – in other words a considerable reduction in network charges for energy-intensive industries – to a maximum of 20 % of the standard rate. Depending on the corresponding processes, production may give rise to load peaks extending to a quotient < 7000 hours. Bearing in mind that the reimbursement of the network charge relates to the whole year. In other words, the duties of the UPS storage system include its having to cap the function of these peak loads: “peak shaving”.
PN: But load management in itself is nothing new. Is it of crucial financial significance to large-scale consumers?
Metzig: That is correct, in principle. As a rule, however, efforts are made to compensate for the encountered load peaks by temporarily switching supplies off, or by delaying their switch-on. Consequently, this mode of load management has tremendous repercussions on production processes. That being the case, it increasingly gave rise to problems for our customers. Consequently, an attractive solution appeared to be to invest in an energy storage system. Given the relatively high costs of investment for storage systems, it is becoming increasingly necessary to resort to “multi-use applications” in order to operate storage systems economically. In addition to conventional peak shaving, this includes buffer storage of regenerative power or a standby capability.
PN: How was the customer’s attention drawn to the solution developed by BENNING?
Metzig: BENNING’s ENERTRONIC modular Storage system with UPS capability gives it a unique benefit which ensures its market profile. And we already had business connections with the parent company. This is a context where BENNING is well-regarded as a versatile turnkey provider specialising in complex, high-availability power supply systems. But the current project was the first one to have been installed at that site, in Saxony.
PN: How was the project approached, and exactly what did the customer receive?
Metzig: At the end of 2018, the initial outline concepts were discussed, followed by a budget quotation in the first quarter of 2019. By the end of 2019, we received the order, once everything had been analysed and the technical details had been sorted out. It was in the summer of 2020 that we completed the project work, production, supply, commissioning and trial run. Our service department has a 320 kVA ENERTRONIC modular Storage system installed on site with the customer, and equipped with eight 40-kVA modules (expandable to ten modules), a supply connection panel compliant with VDE AR-N 4105, a DC connection and communications panel, together with 10 battery cabinets whose energy capacity comes to a total of 300 kWh.
The ENERTRONIC modular Storage system is based on hardware tried & tested on the industrial UPS marketplace. It offers excellent linear peak shaving over the entire load range, and comes with the UPS functionality required in order to protect critical supplies.
PN: In retrospect, what were the particular challenges, and what were the requirements imposed by the customer that meant it was you that won the order?
Metzig: The energy storage system needed to be integrated into the company’s existing infrastructure with – of course – the lowest possible overheads. Consequently, technical criteria dictated just one solution: the Company’s own transformer station, for the installation and integration of the system. The grid structure in place meant that it was ideal to apply connection directly to the low-voltage supply, especially as this is a functionality that comes with the ENERTRONIC modular Storage product. Installation in the switchgear room was not really an option for the customer. The available separate room needed a very compact layout, since the system had to be designed with flexible scalability, to cover the eventuality of any possible adaptations to power capacity. From the outset, thanks to the modular architecture and the advantageously small footprint characterising the ENERTRONIC modular Storage system, we were able to offer ideal solutions, which were very cost-effective. And we imagine that our range of “soft skills” – starting with active customer consultation, passing through the design and interface planning stages and culminating in turnkey handover (conducted by our service department) – all helped to win the day.
PN: Commissioning took place quite a while back. Has there been any feedback from the customer concerning the system’s ongoing operation?
Metzig: For the customer’s parent group, this plant represents something of a pilot project. Now, we have received enquiries for similar storage systems with UPS capability for further locations. I believe that this proves that active peak load management is regarded as being highly valuable in financial terms, especially in conjunction with the UPS functionality as supplied by BENNING.
Our customer is aware that in the near future it will have to face up to further challenges associated with the energy transition, such as the capability to incorporate sustainable energy sources, electrical mobility and enhanced energy efficiency in parallel with the assurance of uninterruptible power supplies for its processes critical to operation at all of its sites. In Saxony, at any rate, it has already set up the optimum conditions for that investment.
PN: We are very glad to hear that, of course. Finally, could you venture to share with us a look into the future? How do you think the market for such systems is going to develop in the future?
Metzig: It goes without saying that this is dependent on a wide range of factors. However, we can foresee that our UPS capability storage systems – fulfilling UPS classification criterion VFI-SS-111 – will be carving out a whole new market segment for themselves. They are markedly more cost-effective than other known applications.
And we can imagine, given the major cost/benefit advantages, that in a great number of fields of industry, the marketplace for conventional energy storage systems is going to merge with the UPS systems marketplace.
PN: Many thanks, Mr Metzig, for the interesting insight you’ve shared with us with regard to this leading-edge project.
Benefits of storage systems with UPS capability
- Economy of operation can be achieved via:
- Peak shaving
- Load levelling
- Optimisation of power draw (“7000-hour rule”)
- Day-to-night energy transfer
- Energy reserve can be defined flexibly
- Storage during low-load phases
- Additional output during high-load phases
- Suitable for lead and lithium batteries
- Own consumption optimised
- Safe UPS operation (VFI-SS-111)
- Power factor correction
Advantages of the ENERTRONIC modular Storage
- Maximum availability
- Minimised operating costs
- Variable component concept can be achieved by:
- Storage and UPS function
- De-centralised, parallel architecture
- Hot plug system with modular expansion facility
- Flexible battery configuration (secondary battery, group battery, individual battery)
- Can be used in conjunction with regenerative energy systems such as solar power, hydro or wind systems
- Option of connection to low-voltage grid as per VDE AR-N4105
- High efficiency
- Rapid return on investment