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Are smart UPS combined with storage systems the best approach in financial terms as we approach the transfer to alternative energy sources?

Hybrid UPS storage systems offer cost-effectiveness and a prompt return on investment, combined with security for critical loads.

For many years now, UPS systems with battery backup have been used successfully in various market sectors – but particularly including industry, telecommunications and IT – for the protection of critical supplies. In parallel, we have experienced the emergence of the widest range of network-controlled energy storage systems, whose development has been prompted by the use of regenerative energy sources such as solar power.
In this article, POWER News (PN) examines the increasing relevance of combining these systems as we approach the change to renewable energy sources.

Then we will go on to examine two projects exhibiting the financial and technological benefits available for a range of companies and of business areas.

In December 2020, the EU member states agreed to reduce greenhouse gas emissions from within the EU by no less than 55 % – by contrast with the previously planned figure of 40 % – relative to the 1990 figure.*1 For this purpose, the EU Commission plans to present a range of legislative proposals, in 2021 for the adaptation of the EU climate and energy regulations currently in place.
In this context, the European Green Deal (abbreviation: EGD) stands as a core project with a comprehensive growth strategy for a climate-neutral economy, thrifty with resources, by 2050. This would make the EU the World’s leading industrial region in terms of climate neutrality.
The achievement of this ambitious climate protection goal will be dependent firstly on the continuous transition from fossil fuel driven power generation towards regenerative energy sources and, secondly, on a significant optimisation of power draw and consumption on the part of Trade and Industry.

Graph of the construction of an energy storage system in conjunction with the ENERTRONIC modular Storage UPS system
The construction of an energy storage system in conjunction with the ENERTRONIC modular Storage UPS system achieves the maximum of flexibility and profitability

Functions of energy storage systems in the fields of grid services, renewable energy sources and applications in industry

Network services

• Primary power control
• Reactive power control
• Voltage stability

Renewable energy sources

• Storage during low-load conditions
• Bridging of troughs
• Avoiding mains usage costs
• Micro grids

ENERTRONIC modular Storage covers load management functions such as peak shaving

Industrial applications

• Peak shaving
• Load leveling
• Micro grids
• UPS operation

Making use of the potential offered by storage technology

The required progress in the establishment and expansion of regenerative energy production will give rise to fluctuations, whose magnitude cannot be predicted, in terms of energy feed. Energy stores provide a greatly needed degree of flexibility in terms of the smoothing out of loads, in combination with efficient load management, and these stores have a significant contribution to make to the definable smoothing-out of the load curve within the grid. They mean that the extremes are rounded off, and that goes for load peaks and surplus energy spikes.

Sustainably reducing the cost of operation

Hybrid UPS storage systems are now available. They are essential hardware in financial terms, as companies approach the transfer to alternative energy sources. These are multifunctional systems which can be incorporated, with appropriate communications interfaces, into EMS’s (Energy Management Systems) that are already available.

This is a field where self-managed UPS storage systems with “island operation capability” offer significant advantages. At all times – irre­spective of ongoing load management functions, such as peak shaving, load levelling or the optimisation of power draw – they assure continued operation for the connected critical supplies in the event of any disruption to the grid.
Smart load management for these hybrid systems offers the simultaneous combination of enhanced reliability and efficiency of power supply with a sustained reduction in operating costs. This technology is ideal for use in all applications where the supply of power from storage systems can be partially or fully deferred in chronological terms.

Rapid break-even on investment costs – thanks to a combined approach

In BENNING’s new ENERTRONIC modular Storage range, it offers individually customised energy storage systems with true UPS function and “on-board” EMS. This smart system is designed for:

  • Industrial applications
  • Storage of regeneratively produced power
  • Micro grids

UPS functionality protects critical supplies from any disruptions on the grid. At the same time, the system – in conjunction with “on-board” EMS – covers load management functions, thus making a significant contribution to a quicker break-even time on investment (by comparison with systems lacking any storage functionality).

Benefits of storage systems with UPS capability

  • Flexibility
  • Economy of operation can be achieved via:
    • Peak shaving
    • Load leveling
    • 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

ENERTRONIC modular Storage Advantages

  • 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

ENERTRONIC modular Storage covers load management functions such as peak shaving and load levelling

ENERTRONIC modular Storage covers load management functions such as load levelling

Single-source turnkey products

On the basis of tried & tested industrial UPS systems, BENNING offers a modular architecture for the construction of cost-effective energy storage systems both for network-controlled and for self-managed plant.

They cover an output range of up to one megawatt per supply point. Moreover, it is possible to install larger systems, with further supply points, within the same common grid.
This decentralised scaling enables optimised, cost-effective integration into an existing infrastructure. And it is also possible to upgrade or to retrofit existing energy storage systems with modular UPS tech to produce smart power supply systems with island operation capability.

Where BENNING supplies a turnkey solution, it regards its role not merely as the manufacturer of hardware but as a system integrator characterised by partnership. Consequently, the projects described below illustrate not only the technical & financial aspects but also the consultation, planning & development services that will be entailed in successfully meeting the range of customers’ specific needs

With all of this in mind, PN was able to meet up with Mr Ronald Metzig (Head of Office East, BENNING) and Mr Claus Kirmaier (Head of Office South, BENNING).

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.

„Active peak load management in conjunction with UPS functionality ensures technical and financial stability.“

Ronald Metzig,
Head of Office East, Germany,

System solution of the Biogas Gröber Ruf GmbH & Co. KG
The UPS protects the critical loads from mains disruptions. At the same time, in conjunction with the “on-board” EMS, the system takes on load management tasks and thus contributes significantly to faster return of the investment compared to systems without a storage function.
ENERTRONIC modular Storage system with 5 modules front view
Example of a flexible scalable ENERTRONIC modular Storage system with 5 modules

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.

Further information

contact: Ronald Metzig
telephone: +49 172 2859286

For Biogas Gröber Ruf GmbH & Co. KG, a producer of regenerative power in Fuchstal, southern Germany, Mr Kirmaier was responsible for completing a turnkey UPS storage solution (160 kVA / 462 kWh).

Hardware for multiple applications

BENNING supplies modular architecture – based on tried & tested industry grade UPS systems – for construction of cost-effective energy storage systems.

PN: Mr Kirmaier, would you kindly tell us about your customer and their field of business, in brief?

Kirmaier: Biogas Gröber Ruf GmbH & Co. KG – as the name implies – is a company which generates energy on a climate-neutral basis. Using the gas generated from biomass, the customer drives BTTP (Block type thermal power station) gas motors which generate electricity and heat with a high degree of efficiency. In close partnership with local farmers, the customer – which is based in Fuchstal, Bavaria – obtains the required biomass from cultivation in the region. In addition, the customer makes use of the roof areas of its operational buildings to generate photovoltaic energy.

We have come to appreciate how future-oriented and innovative this customer is. We immediately noticed that this Company’s fundamental policy is to give priority to the sparing and intelligent use of ecologically generated power.

The Company’s affiliations include its capacity as a partner of the Fuchstal Energy Future project, which is funded by the Federal German Ministry for the Environment and Natural Conservation. Photovoltaic systems, a hydro power station, a municipal wind farm and Biogas Gröber Ruf’s biogas system have all been combined, within this project, to form an innovative energy grid that spreads across a number of communities.
The goal of logically applying renewable energy sources then gave rise to the customer’s further considerations with a view to optimisation. We were able to provide the customer with tremendous support.
Previously, in phases where there was no solar radiation – in other words on rainy days or at night – the plant’s own electrical power needs in terms of operating the system were covered on a round-the-clock basis by the biogas BTTP. The power draw entailed in that context, representing approximately 9% of the generated power, was consequently no longer available to be fed into the power supply grid.
By virtue of investing in an energy storage system which provides for buffer storage of the surplus solar power generated in the daytime – and not required to cover the plant’s own needs – it was possible to achieve a significant increase in the proportion of own-generated solar power that could be used in-plant. That meant that only a residual quantity – approximately 2% of the more ecologically valuable biomass power (also available at night) – could be drawn upon to cover the plant’s own requirements.

It was possible to increase the proportion of own consumption of generated solar power to the commendable figure of 80%. And there is a further benefit from a commercial viewpoint, because under EEG (German-language abbreviation for Sustainable Energy Regulations) the biomass power feed earns higher payment than solar power does.

PN: In other words, a greater proportion of the more financially profitable biomass electricity can be fed in: an undeniably attractive layout. Mr Kirmaier, you cover southern Germany. Prior to this project, did you already have an ongoing business relationship with Gröber Ruf GmbH & Co. KG?

Kirmaier: For us, this customer was a “new acquisition”. On the other hand, our initial contact with them came about via a company which is networked with ourselves. For a considerable time, Mr Ruf had been searching in vain for a system partner who could be entrusted – in the capacity of a fully responsible turnkey partner – with the operation of an energy storage system consisting of a combination of the components of a current transformer, a battery system and incorporation in the energy management system. Their company then received a crucial hint – from a company which is in partnership with ourselves (in the field of battery technology) – thus putting them in touch with BENNING.

PN: Accordingly, we could say – possibly with a little exaggeration –that you won the order because BENNING is the only supplier who was prepared to accept such a complicated challenge?

Kirmaier: In fact it was the customer who later told us (in the course of a project meeting) about the long and futile search they had previously undertaken, to find a suitable provider. And they emphasised how particularly concerned they had been (on top of all the technical and financial aspects) by the fact of the need to have competent consultation at the outset when it came to the eventual order being issued.
Perhaps I could best characterise the situation’s complexity as follows: The infrastructure already in place with the customer consisted of several biogas generators, a solar power system and various feed inverters. The plant’s consumption and energy feed was controlled by an EMS – energy management system – already in place with the customer. In addition to the hardware, in other words, there was the communications link for our UPS and storage systems together with the BMS – Battery Management System – feeding into the customer’s data flows.

PN: You mentioned technical aspects, just now. Why did the customer want a combination of battery systems and UPS plant? Would an energy storage system not have been adequate?

Kirmaier: Amongst other functions covered by the UPS system, it also provides for an increase in the operational reliability of the plant, because the sophisticated automation system consisting of sensors, evaluation computers, actuators, feed pumps and managed stirring drives could not tolerate any grid fluctuations / failures.

Any fault would have given rise to considerable complications in the operation of the plant. And a worst-case occurrence would have given rise to safety-critical situations, because plant parameters such as gas pressure or volumetric levels would then have been unavailable. In order to avoid such a scenario, a portion of the energy which is available from the batteries is not released to cover our own needs, but is kept in reserve to guarantee continued supply for the sensitive plant technology. In the event of any grid failure, the ENERTRONIC modular Storage system – which operates simultaneously as a storage system and as a UPS – will cut in and support the reliable continuation of operation by virtue of its energy reserve.
In addition to the basic function which covers the storage and release of the climate-neutral production of electrical power, then, the system – without any significant additional costs – provides absolutely interruption-free, continued power supply to sensitive supplies should any grid failures arise. This comes in conjunction with an extended service life, since it filters out any of the grid impurities such as harmonics or transient voltages that would otherwise reduce the service life of the plant components – most of which are expensive.

PN: So, looking once again at ENERTRONIC modular Storage: Could you kindly provide us with a brief description of which system components were installed and commissioned by BENNING Service in the autumn of 2020, please?

Kirmaier: The outcome of the early-2020 planning & analysis phase was the requirement, on the hardware side, for a system consisting of ENERTRONIC modular Storage with 160 kVA output (4 modules, each providing 40 kVA), a BMS and a li-on energy accumulator of modular layout, with an energy capacity of 462 kWh (2 x 7 x 33 kWh). It was not viable – for financial reasons – to consider a solution with conventional lead batteries, although the ENERTRONIC modular Storage solution is also suitable for such an application. It was possible to make connection directly at the low-voltage level (400 V AC / VDE AR-N4105). This approach meant that there was no need for the plant to invest in its own transformer.
The system’s design is based upon maximum availability, with redundancy. The advantages of modular architecture – such as quick & straightforward servicing, flexible scaling and modest space requirements – were as convincing as the benefits of high system energy efficiency, added safety and a quicker breakeven time.

PN: Just there, you emphasised on the hardware side. Why was that?

Kirmaier: That’s right: an important module of the project was the smart networking of the already existing EMS (type S7) with its new components and specifically with the BMS. The corresponding integration was carried out by our engineers hand-in-hand with the customer’s EMS specialists. The Monitoring and Control Unit (MCU) – developed by ourselves and used in many areas of industry and telecommunications – provides for the widest range of manufacturers to be connected up to the EMS with a wide range of supported protocols and interfaces.

PN: Mr Kirmaier, many thanks for speaking to us today. It was most interesting for us to learn how a biogas power station can be operated with such great efficiency – by virtue of investing in an energy accumulator system with UPS capability – can be operated not only with greater safety but also using the various payment models under EEG (sustainable energy regulations) – looking at things from the commercial viewpoint – and with such impressive efficiency as to ensure a rapid ROI (return on investment).

Further information

contact: Claus Kirmaier
telephone: +49 8332 936363

„Optimising the cost-effectiveness of a biogas power station by means of smart use of ecologically produced power combined with smart networking of all systems involved.“

Claus Kirmaier,
Head of Office South, Germany

Specimen system solution
Biogas Gröber Ruf GmbH & Co. KG

• Energy accumulator + UPS
• Modular system
• Connection direct to 400 V AC
• No transformer needed
• Inverter output 160 kW

• Flexible expansion capability
• Modular-design li-on energy accumulator

• Projected useful battery life: 10 years

• Reserve capacity for UPS consumers

• Reserve capacity for particular operating cases

Smart networking of a pre-existing type S7 EMS with the new components.
Smart networking of a pre-existing type S7 EMS with the new components.
Display of the monitoring und control unit (MCU)
The MCU (monitoring & control unit), with its diversity of supported protocols and interfaces, makes it possible to connect the system to EMSs of the widest range of software manufacturers. The system controller (MCU 3000) integrated into the power supply system cabinet door comes with a 10.4 inch touch display.


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