pv magazine Storage Highlights’ ranking 1 to 24

In the run-up to the Energy Storage Europe event, to be held in Dusseldorf, Germany between March 13 and 15, pv magazine called on exhibitors to submit their energy storage highlights to our expert jury (see below for the members).

We have already presented, in detail, the top 10 products and projects in the printed pv magazine energy storage special, which was published in cooperation with Energy Storage Europe; and published online the top five.

However, the solutions that did not make it to the top of the list are also worth a visit, which is why we have presented all of the participants below, including a short summary of their solutions and booth numbers.

1. Combined gas and battery grid services power plant

Younicos, Hall 8b/D02

Younicos submitted a project in which the company, together with the Technische Werke Ludwigshafen, developed a combined balancing power plant, coupling a 4 MW gas turbine with a 9 MW battery with a capacity of 6.5 MWh. The intention is to provide both primary and secondary control power. The plant is still under construction. Gas turbines can only offer balancing power if they are up and running, otherwise their reaction time is too slow. For battery storage to be able to offer this alone it must be equipped with a lot of storage capacity. The charm of the solution presented is that within this technical unit the gas turbine does not have to run continuously, but the battery initially takes over, and the gas turbine only intervenes when the duration of the control power exceeds the capacity of the battery. So, the combined gas and battery storage power plant reduces the so-called must-run capacity of conventional power plants.

2. Multi-string three-phase battery inverter technology

E3DC, Hall 8b/E22

The company, has submitted a new technology for a DC-DC converter for battery storage systems, with which users can better control the state of charge. The challenge for the innovative state-of-charge-control is that no lithium battery system can have an accurate state of charge measurement without being discharged and charged from time to time, states the company. If you measure the state of charge in this way, the battery may be empty in an emergency. The solution is to operate two battery modules asymmetrically. As one is discharged, the other holds a defined state of energy. In addition, the power electronics have a high discharge capacity with efficiency of up to 98% due to a new topology with galvanic isolation and an ultra-high frequency allowing for small components.

3. Large-scale storage solution

SMA, Hall 8b/B22

In 2017, SMA introduced its large-scale turnkey solution Medium Voltage Power Station to the global market. One container has an output power of 5.5 MW. Unique to this solution is that the Sunny Central Storage with grid forming capacities acts just like a rotating mass in a power grid, writes the company. The technology mimics the function of rotating mass in the grid to load and subsequent frequency changes. When load increases, rotating masses are decelerated, but their inertia dampens the effect until the generator power is increased. To do so, there is a distribution of responsibility between Grid Controller and Sunny Central Storage. Functions regarding grid stability that need reaction within milliseconds or less are located in Sunny Central Storage, directly avoiding any communication to fulfill these tasks.

4. Power electronics for battery inverters

Fraunhofer ISE, Hall 8b/B39

According to Fraunhofer ISE, the Cell-Booster and the power electronics for the project “Netefficient” permit high efficiencies on the one hand, and small construction volumes on the other. The cell booster converts the typical 48 volt output of a low voltage battery with an efficiency of 97% to 700 volts, as required, for example, by a three-phase battery inverter. According to Stephan Liese, Head of Group Distributed Generation and Storage, the key factor enabling this high efficiency is the high frequency with which the transformer is operated, and which is even modulated. In addition to the increased efficiency, the high frequency also helps to reduce the size of the housing. The electronics for 1 MW output power fit into a standard 19 inch switch cabinet.

5. Scalable Methanation plant

Electrochaea, Hall 8b/ D12

The methanothermobacter thermautotrophicus – a small green bacterium – is the basis of this energy storage highlight. Electrochaea uses it to convert hydrogen to methane. The company uses a variant of the bacterium, named archeva, as a biocatalyst in a low temperature process. It developed the technology to a state where it can be used in large methanation facilities, and the first demonstration plant is running near Copenhagen with 1 MW electrical power. The efficiency of the methanation exceeded 80%, writes Electrochaea. Biomethane can be used without limitation or expensive investment in the existing natural gas grid.

6. Large-scale storage business model in the distribution grid

Smart Power, Hall 8b/E13

German EPC Smart Power is working on a promising solution for making large-scale storage systems usable in the distribution grid despite regulatory hurdles. The utility Stadtwerke Trostberg Energieversorgung is charged €113/kW peak load at the transformer station to the 110 kV grid. By peak shaving in the distribution grid in the order of 11%, this payment can be reduced. For this purpose, Smart Power is installing a 1.5 MWh/1.2 MW storage system on behalf of a retail company. An annual revenue stream of about €59,000 is expected from the peak shaving use case, and an additional €89,000 will be generated from being active on the primary control market. The tricky point, however, is compensation. The company emphasizes that the installation is not simply a demonstration project, and that it is planned to be profitable without any subsidies.

7. Storage in rural distribution networks stabilized the grid

Abo Wind, Hall 8b/D39

Tunduma, a small Tanzanian town at the border with Zambia, is connected to a 220 kV transmission grid. The grid is characterized, writes Abo Wind, by “large distribution networks at 33 kV supplying thousands of small transformers.” The overhead lines are working at maximum capacity, leading to high losses and a drop in voltage of almost 20%. Abo Wind has evaluated how the grid can be stabilized using solar and storage. The installation, currently in the development stage, will stabilize the voltage level in the distribution networks between 95% and 105%. This will allow more consumers to be connected and SMEs to profit from better grid quality and fewer blackouts.

8. 10 MW-storage plant with black start capability

Wemag, Hall 8b/C01

Northern German utility Wemag made headlines several years ago with what was then the largest battery storage power plant in the country. In 2014, 5 MW went online for marketing in the primary control energy market. In 2017, this battery storage power value was extended to 14 MW and made black start capable. Now it has a capacity of 15 MWh, and provides control capacity comparable to that of a 100 MW gas turbine. The company emphasizes that the extension was not subsidized, but for the black start ability, a state subsidy of €180,000 was paid. Wemag now wants to offer its expertise in construction, operation, and marketing to other interested parties.

9. Adjustable water heater with further functionality

Fronius, Hall 8b/C18

According to Fronius, the special feature of the device is that besides the necessary function – heating the hot water boiler – it also includes more features than usual: It includes comprehensive monitoring, can be networked via WiFi, LAN, or RS 485, works in combination with other heating elements, and above all is steplessly controlled. The single- phase device has a power of between 0 and 3 kW, the three-phase device between 0 and 9 kW. Minimum and maximum temperatures can be defined, and depending on the setting, the device heats up to over 60 °C for Legionella (pathogenic bacteria) prevention in the time intervals set, even if there is no excess of solar power.

10. The water battery

Max Bögl, Hall 8b/E31

Max Bögl has built wind turbines with embedded tanks for a water reservoir. The wind turbines are located on a hill about 80 km from Stuttgart. The lower reservoir is down in the valley. One reason to build hydro storage co-located with wind is, according to Max Bögl, that spatial demand for the upper reservoirs is only marginally larger than that for wind turbines. Capex for the storage part is €300 to €400/kWh. Max Bögl aims to reduce the demand for conventional pumped storage power plants, which often require extensive alterations to the landscape and elaborate planning procedures. In addition, the new system reveals attractive marketing opportunities in the electricity sector.

10. Organic redox flow battery

Jena Batteries, Hall 8b/E03

Jena Batteries is developing a redox flow battery that uses organic electrolytes instead of vanadium-containing electrolytes. It is more environmentally friendly, because it is free of heavy metals and hazardous acids, the company says. In addition, there is no fire risk. Unlike vanadium redox flow batteries, the price for the new technology is independent of commodity markets and depends more on scaling, writes the company. Also for the stack, which sits between the two tanks of a redox flow battery and in which the energy conversion takes place, one could use cheaper materials, since it does not have to withstand aggressive acids. The first pilot plant with a 10 kW/40 kWh battery will now be installed.

12. Charging station with PV and redox flow battery

Schmid Energy Systems, Hall 8b/B24

Schmid Energy Systems has developed a carport with several electric filling stations and integrated redox flow storage. The roof is equipped with a photovoltaic system. If many cars refuel at the same time, the storage buffers the load so that the grid does not need to be reinforced so much. The battery can be charged when there is excess PV energy. The first “EverFlow” Storage Container was delivered in September 2017 to Saarbrücken, Germany. The goal of this project is to show that this “grid-independent” charging station can maximize the usage of self-produced green energy for charging electric vehicles and minimize the use of electricity from the grid. The implementation of a smart Energy Management System (EMS) is also part of the project. By using a ticket system, the usage of the e-cars in the carpool can be planned in an efficient way. Information like the day, destination, time of departure, weather forecast, state of charge of the VRFB as well as the connected cars are part of that calculation.

13. Large-scale hydrogen production from PV power plants

NEL Hydrogen Electrolyser, Hall 8b/ B11

According to NEL, the standardized 50 MW electrolyser plant can support more than 40.000 fuel cell electric vehicles (FCEV) on an annual Basis. Calculations of NEL show, that with a 50 MW electrolyser one can be competitive with todays gasoline prices. During day time, the electrolyser utilizes solar power or grid power and reduces risk of curtailment stemming from higher renewable energy shares. At night time, the electrolyser draws power from the grid or wind and reduces production during high demand periods. Drawing power from both the grid and renewables enables a steadier and less costly hydrogen production.

14. Modular Energy Storage Solution

Commeo, Hall 8b/D01

One challenge related to using lithium-ion batteries in a larger than residential scale is the heat generated during charge and discharge of the battery system, writes Commeo. Especially in applications requiring C-rates above 1C it is crucial to dissipate the heat to ensure safe operation and long lifetime. In the Commeo energy storage solution all lithium-ion cells are thermally connected to an anodized aluminum profile, which features large surface area cooling ribs. Depending on the utilized lithium-ion cell, which is chosen according to the individual application, the energy storage block can be discharged at current rates much higher than 1C, writes the company. One block has a capacity of 1.4 kWh and can deliver 2.8 kW continuously. It includes a battery management system (BMS), has a nominal voltage of 50 V and industrial standard power plugs in Poka-Yoke design. So the system is scalable in steps of 1.4 kWh.

15. Siestart hybrid gas turbine and battery

Siemens, Hall 8b/D40

Conventional power plants with rotating mass require a minimum of 5 to 10 minutes to start. That's too much time to react quickly to load changes. In combination with a storage system, however, gas turbines become black start capable, and can thus restore the network in the event of serious disruption. That is why Siemens has developed a hybrid solution for gas turbine and gas and steam power plants under the name Siestart. In addition to the network services offered by a battery storage system, it significantly reduces the thermal stresses on gas turbines, which has a positive effect on the lifetime of the machine. In addition, the efficiency of the power plant will be increased, writes Siemens.

16. Decentralized DC storage technology platform for PV plants

Fluence, Hall 8b/D40

According to Fluence, “SunFlex Energy Storage” is a technology platform for photovoltaic plants, that aims to eliminate solar variability and to allow facilities to sell up to 50% more solar energy per site. It has a power capacity of 2 to 100 MW and more, and an energy capacity that lasts for more than two hours. The storage architecture unites the batteries and PV on the same side of the DC bus in order to take advantage of higher PV-to-inverter ratios and maximize solar yield. The energy storage is distributed throughout the solar field, sited with the inverters, in order to better connect into solar arrays. According to Fluence, the platform enables developers to add more solar panels without the cost of changing their interconnection and provides the ability to stack additional grid services, such as frequency regulation, capacity firming, and ramp rate control.

17. Picea: a residential Power2Gas storage and heating solution

Home Power Solutions, Hall 8b/D08

Home Power Solutions combines energy storage, heating support and indoor ventilation in one compact system for residential homes. Picea contains not only batteries, but also an electrolyser and a fuel cell for reconversion of the hydrogen to electricity and heat. The hydrogen tank is supposed to be placed somewhere in the garden. With that, residential homes can become highly autonomous to the electric grid and even in German winters, with three months without much solar irradiation. And it reduces heating cost by utilizing waste heat, the company states. So far, Home Power Solutions has installed four systems across Germany and is testing them.

18. Voltage balancing solution by Fenecon/Refu

Fenecon, Hall 8b/G02

The joint Fenecon-Refu balancing solution consists of three main components: inverter, battery system and energy management controller. The REFUhybrid 100 inverter is built to provide continuous phase balancing. The REFUhybrid 100 will correct current imbalance up to 33% of its nameplate rating, even if the phase imbalance is continuous. Together with the BYD lithium-ion high-voltage battery system it can help public grid operators and C&I customers to eliminate the effects of imbalance as there are low performance and utilization of electrical equipment, high neutral conductor current, increased grid losses, high stress on MV transformers and cables and process interruptions (for example overcurrent tripping).

19. MyReserve Matrix for commercial application

Solarwatt, Hall 8b/G23

Solarwatt has developed the MyReserve Matrix storage system to meet the diverse needs of industrial and commercial customers. The system consists of two components: 1. MyReserve command as DC converter for installation between battery and standard PV inverter and 2. MyReserve pack, a lithium-ion battery module. The installation of additional battery modules allows the system to be expanded in steps of 2.4 kilowatt hours (capacity) and 800 watts (power). Solarwatt claims the system has a round trip efficiency of 92% and is compatible with all PV inverters. As a result, it can also be retrofitted in existing plants.

20. Combining a power plant with a battery

Robert Bosch, Hall 8b/E39

To increase the flexibility of a conventional power station, Bosch combines it with a battery storage system. While the operating periods of conventional power stations may be getting ever shorter, due to more renewable power in the grid, their operation demands more flexibility. To enable EnBW to provide primary control reserve at a power station, two containers of 2.8 MWh lithium-ion batteries, six 900-kW-inverters, six 1000-kVA-transformers, power supply, infrastructure and an optimized system control were implemented to the site.

21. State of the art energy storage system for refugee camp in Northern Iraq

Autarsys, Hall 8b/G05

Autarsys is set to manufacture an energy storage system including a 300 kWp photovoltaic system with software that will transform the way the residents of a refugee camp receive power. The intelligent energy management software will enable camp administrators to prioritize and schedule the delivery of power based on residents’ most critical needs. Refugee camps are traditionally powered by diesel generators or rely on the local public grid, which provides consistent power only at night. The first phase of the project will have the capacity to power one section of the Mam Rashan refugee camp at a time during the day.

22. Scalable hybrid energy storage system combines lead and lithium

Hoppecke, Hall 8b/E16

The scalable hybrid energy storage system “Sun Systemizer” combines the advantages of lead and lithium batteries and allows both to be used together in any combination. Lead-acid batteries are a mature and proven technology and also less expensive. Lithium batteries cost more, but in return are smaller, lighter and more powerful. In 2017, Hoppecke built the first grid-scale hybrid energy storage system at a factory site in Brilon-Hoppecke, that now stabilizes the European Network of Transmission System Operators for Electricity (ENTSO-E). The smaller solutions with energy capacity from 100 kWh are available as standard units.

23. Storage system with particularly high charging and discharging power

NES, Hall 8b/G04

NES has developed DC-coupled charging for Li-ion high voltage batteries, that according to the company, has five times higher charging and discharging efficiency compared to its competitors. The charger has 2 independent inputs on which the processing power can be adjusted (fixed voltage or performance characteristic or MPP control) and with an input voltage up to 950 V. The charging solution provides the possibility of bidirectional connection for charging and discharging with authorized electric cars. Flexible input parameters allow different energy sources to be connected. The scalability of both the charger and the storage units enables performances up to 120 kW and storage size up to 432 kW

24. NiMH batteries also for high voltage

Nilar, Hall 8b/D27

As an alternative to the lithium-ion battery, Nilar has further developed the nickel-metal hydride (NiMH) battery technology, which is now available as a high-voltage battery with 60-600 volts. Although NiMH batteries are not as small and lightweight as lithium batteries, they could well be used for heavy duty equipment, hybrid vehicles, and stationary energy storage applications, explains Nilar. Thanks to the stable nickel metal hydride chemistry, the bipolar battery does not pose an explosion hazard and can offer a high performing storage solution packaged in a safe and environmentally friendly battery, the company says.

Not participating in the first round of the pv magazine highlight ranking, but also at Energy Storage Europe

Battery storage system storing electricity for €0.09/kWh

Tesvolt, Hall 8b/E01

By expanding the capacity of the TS HV 70 high-voltage storage system, Tesvolt was able to offer a price of 9 cents for storing one kilowatt hour for the first time at the end of 2017, according to the company. In the TS-HV 70 high-voltage storage system, several parameters have been adjusted to increase efficiency and thus cost-effectiveness. The system’s discharge capacity has been boosted to as high as 75 kilovolt ampere (kVA). Customers can install either 14 or 16 battery modules.

Modular energy system Power-Blox PBX200

Stäubli Electrical Connectors, Hall 8b/A31

Swiss company Power Blox has developed a product that enables the user to start his own mini-grid. It consists of storage blocks that can be stacked and connected easily. In the lithium version, a block has a storage capacity of 1.2 kWh and delivers a continuous output of 200 watts. Photovoltaic modules, diesel generators or small wind turbines can be connected to the integrated hybrid inverter. There are two AC interfaces per block, with an input and output voltage of 230 volts. In order to be able to concentrate on further development, Power-Blox cooperates in sales and production with the Swiss company Stäubli. Together, they want to develop a blockchain application, for example, for billing the electricity.

Bidirectional battery inverter blueplanet gridsave 50.0 TL3-S

Kaco New Energy, Hall 8b/B03

The bidirectional battery inverter Blueplanet gridsave 50.0 TL3-S from Kaco New Energy has 50 kilowatts of power and an efficiency of 98.5 percent. It is intended primarily for commercial and industrial sized energy storage solutions and scalable to the megawatt range. As a special feature, the manufacturer emphasizes that it not only operates parallel to the AC, but also on the DC side. This allows multiple inverters to be connected to a single high-capacity battery. The battery inverter is controlled by a battery management system with the widely used Sunspec interface Modbus TCP.

The Energy Storage Highlights Jury comprises:

• Logan Goldie Scot, who heads up the Energy Storage insight team at Bloomberg New Energy Finance.
• Tobias Federico, Founder and Managing Director of consulting institute Energy Brainpool.
• Dirk Uwe Sauer, Professor of Electrochemical Energy Conversion and Storage Systems Engineering at RWTH Aachen University.
• Julian Jansen, Senior Market Analyst at IHS Markit Technology.
• 
Stephan Schnez, Senior Scientist in Corporate Research at ABB in Switzerland.

Read more about the Energy Storage Highlights ranking, criteria and the selection process in the pv magazine energy+storage special.