In November, the European Marine Energy Centre (EMEC) in Scotland announced it would be installing a 1.8-MWh flow battery at the organization’s tidal energy pilot site on the Scottish island of Eday.

This novel blend of tidal power technology and flow battery technology powers EMEC’s on-site hydrogen production facility. The setup will allow for continuous green hydrogen production from a variable renewable energy source. Produced by the UK-based Invinity Energy Systems, the flow battery system to be utilized at the EMEC tidal facility will be assembled from eight separate modules. The project is expected to go live by the end of 2021.

Dependent upon rising or falling tides, tidal power is predictable yet highly variable. There are four inherent cycles to tidal energy each day. By comparison, solar energy has just one charge and discharge cycle per day.

Due to this variability, power storage is necessary to properly regulate tidal power technology as an energy source. With conventional lithium-ion batteries degrading significantly over time, flow battery technology has emerged as a promising alternative. After a technical review of its system, the EMEC established that flow batteries would be ideal for its use of tidal power for hydrogen production.

At the EMEC’s facility, the flow battery will capture electricity generated during periods of high-power generation so it can be discharged during low power periods, creating on-demand electricity to make hydrogen through the use of a 670-kW electrolyzer.

Energy storage systems based around vanadium redox flow batteries (VRFBs) are being developed for residential use in Australia by partners Australian Vanadium (AVL) and Gui Zhou Collect Energy Century Science and Technology.

AVL made an announcement of the news to the Australian Securities Exchange yesterday. While the vast majority of new household battery systems are based around lithium-ion, an AVL representative told Energy-Storage.news that the advantages of a flow battery could include the ability to “store a lot more energy”, while the product is “inherently non-flammable”. The spokesperson also pointed out that the vanadium electrolyte can be reused at the end of the battery’s mechanical lifetime.

A 5kW / 30kWh system will be installed in Perth, Western Australia, to test out the technology and concept and provide feedback for product development. The system is being connected to the grid using an inverter approved by the national Clean Energy Council, which means it can be connected to a solar PV system and used to store energy for self-consumption at the site or for export.

With household lithium-ion systems generally in the range of about 7kWh to 15kWh in Australia, AVL believes that as well as simply enabling more self-generated power to be used onsite, VRFBs could be an answer to flattening Australia’s ‘duck curve’, enabling households to sell their energy back to the grid much further into the peak after solar generation drops off.

“VSUN Energy has seen a significant number of inbound enquiries for a grid connected, long duration residential VRFB to fill a space that is currently met by short life, short duration, less flexible and less safe energy storage solutions. Using solar energy at a time that suits the householder is the ideal application for VRFB energy storage,” AVL managing director Vincent Algar said.

Australian Vanadium’s battery integrator subsidiary VSUN Energy has ordered the system from Gui Zhou Collect Energy, which is a flow battery R&D and industrialisation company headquartered in Guizhou, China, and trading under the name CEC VRFB Co.

The new CEO at VRB Energy, a maker of vanadium redox flow battery energy storage devices, claims that ongoing improvements to its technologies will allow it to outcompete lithium-ion energy storage in the coming years.

VRB Energy said this week that Dr Mianyan Huang, a leading expert on vanadium flow battery technology and chief technology officer (CTO) and president of its China-based subsidiary has been promoted to chief executive officer (CEO).

Huang – who VRB said has 12 “key” flow battery material and system design patents to his name – actually took over on 1 July from previous CEO John Wang, but the announcement has been left until now. Wang had been in the role since late 2017 and came from a management consulting and technology background.

Additionally, the company announced that Dr Huang has been overseeing testing for the company’s forthcoming Gen3 cell stack design. VRB claimed that it enables a 30% increase in energy density, based on proprietary components developed in-house by the company including membrane and bipole materials. It also features improvements in electrode and cell frame design, the company said.

“This testing shows that our Gen3 technology will be able to achieve a 10% improvement in overall efficiency while simultaneously reducing battery size and lowering cost for our customers. This is just one of many improvements that will enable us to deliver a complete energy storage system for less than forecasted lithium-ion battery pricing, and with 15-40% better levelised cost of energy (LCOE) performance,” the CEO said.

Redox flow batteries allow for the decoupling of energy and power within the cell stack, meaning that to increase capacity and storage duration the tanks of electrolyte that store energy simply need to be scaled up and that repeated cycling does not cause degradation of cells. Meanwhile the technology’s proponents claim it poses less fire risk and features more easily recyclable components than lithium-ion.

Researchers at the University of Southern California looking to crack the renewable energy storage problem have developed a new version of a redox flow battery from inexpensive and readily-available materials.

Though there are huge lithium-ion battery installations from the likes of Tesla that can store energy harvested from renewables like wind and solar, they’re not exactly cheap. The USC researchers looked to an existing design that stores energy in liquid form.

In the so-called redox flow battery, a positive chemical and a negative chemical are stored in separate tanks. The chemicals are pumped in and out of a chamber where they exchange ions across a membrane – flowing one way to charge and the other to discharge.

Though such systems have previously used expensive, dangerous and toxic vanadium and bromine dissolved in acid for their electrolytes in the past, we have seen recent designs that replace those with organic or more environment-friendly alternatives.

For its design, the USC team used a waste product of the mining industry and an organic material that can be made from carbon-based feedstocks, including carbon dioxide, and is already used in other redox flow batteries.

In tests, the iron sulfate solution and Anthraquinone disulfonic acid (AQDS) battery was found able to charge and discharge hundreds of times with “virtually no loss of power.” The researchers say that the inexpensive nature of the materials used could also lead to significant electricity cost savings compared to redox flow batteries using venadium, if manufactured at scale.

“To date there has been no economically viable, eco-friendly solution to energy storage that can last for 25 years,” said lead author on the study Sri Narayan. “Lithium-ion batteries do not have the long-life and vanadium-based batteries uses expensive, relatively toxic materials limiting large-scale use. Our system is the answer to this challenge. We foresee these batteries used in residential, commercial and industrial buildings to capture renewable energy.”

The latest volume of PV Tech Power, Solar Media’s quarterly technical journal for the downstream sector, is now available to download free of charge.

This edition’s cover story comes from the deserts of the Middle East, where researchers are getting to grips with the issue of soiling and what can be done to prevent it.

We also take an extensive look at how solar is making great strides in the Middle East, and SolarPower Europe provides a glimpse at how digitalisation is taking over the solar ecosystem.

As always, ‘Storage & Smart Power’, the dedicated section curated and created by Energy-Storage.news, also returns as part of the magazine. This quarter, we look at:

Contenders: Long-duration technologies and who’s behind them

Some of the promising long-duration energy storage technologies – and their champions. While lithium-ion batteries get most of the headlines, long-duration energy storage solutions are gaining ground. We’ve profiled some of established and emerging concepts in this increasingly important class of storage technologies.

Redox flow batteries for renewable energy storage

A team from CENELEST, a joint research venture between the Fraunhofer Institute for Chemical Technology and the University of New South Wales, charts the rise of redox flow batteries. A truly deep dive, the article is a thorough examination of various types of flow energy storage and what stands between them and greater success.

Taking charge: Energy Storage Association CEO Kelly Speakes-Backman

Despite making huge strides forward, the energy storage industry is far from done with its work in helping stakeholders across the value chain understand the technologies and the roles they can play in a renewable energy future. Former regional utilities’ commissioner Kelly Speakes-Backman is one of the people working to make that happen every day. With more than 180 member organisations, ESA is speaking up for a big wedge of stakeholders in the energy sector that see renewables and energy storage as a day-to-day business as well as an aspiration and social good.

Many thanks to all that downloaded the PV Tech Power Volume 20 including the Energy Storage Special Report 2019, which is also still available as a standalone PDF from the ‘Resources’ section of this site.

Flow batteries have so far, failed to live up to the disruptive potential they promise, a new report says, but authors Alex Eller and William Tokash at Navigant Research have identified 12 leading vendors in the nascent field, based on metrics of strategy and execution.

In an industry (sub)segment that has already undergone rapid consolidation and seen some of those considered early leaders such as VIZn and Immergy fall by the wayside in the past three or four years, Navigant names Cellcube – which itself once had a rollercoaster journey of changing hands and investors – as top in the chart.

In the preamble to a 2018 interview with Cellcube president Stefan Schauss on this site in 2018, I wrote that the fortunes of Cellcube’s redox flow battery energy storage, spun out of technology developed at Gildemeister, “have been an interesting mirror to those of the overall technology class”.

Owned by junior mining entity Stina Resources, Cellcube Stefan Schauss told Energy-Storage.news the company had ambitions to realise full vertical integration, with the company seeing progressive shifts to longer durations of energy storage already seen in the energy market in places such as California as “just the tip of the peaking iceberg”.

Leaders, contenders alike are waiting for opportunity to scale up production

Joining Cellcube in a category of two marked ‘Leaders’ in the Navigant report (all 10 other companies named are described as ‘Contenders’) is Japan’s Sumitomo Electric, perhaps largely by virtue of deploying a 60MWh flow battery on the northern Japanese island of Hokkaido a few years back.

More recently, towards the end of 2017 the company said it would take its flow systems into the international market, beginning with a large commercial pilot project in Belgium. Then, at the end of 2018, Sumitomo also said it would connect a 2MW / 8MWh demonstration into the California wholesale market to provide frequency regulation and trade-based supply.

The potential advantages of flow batteries – and the challenges faced by providers of the various different flow technologies and sub-chemistries – are examined in great depth, in a feature article to be included in the forthcoming edition of our quarterly technical journal, PV Tech Power (vol.21). Co-authors Jens Noack, Nataliya Roznyatovskaya, Chris Menictas and Maria Skyllas-Kazacos from CENELEST, a joint research venture between the Fraunhofer Institute for Chemical Technology and the University of New South Wales chart a deep dive into everything from how redox flow batteries work, to the supply chain and sustainability of materials, to the challenges still ahead for commercialisation.

Defense and aerospace giant Lockheed Martin wants to be the first disruptive company of the flow battery era, with the expectation that its first devices will go into series production before the end of this year.

Energy-Storage.news met earlier this year with company VP for business development Dan Norton, who said that Lockheed Martin’s own coordination chemistry flow battery (CCFB) had neared the end of its development and test programme, which had gone “swimmingly and as planned”. The product has been some time in development, originally teased as expected to hit the market before the end of 2018, although this target was always understood to be flexible.

“We begin serial production on our unit number 1 towards the end of the year and we’ll go for full launch in the market some time next year,” Norton said, in an interview taped at this year’s Solar Power International in late September but only cleared for publication approval later.

That in itself is an indication of Lockheed Martin’s focus. The flow batteries are being developed within Lockheed’s Missiles and Fire Control division, and Norton said that as an energy security asset, the technology and market is “the next logical progression” for the company.

While Lockheed has already launched GridStar lithium and seen successful deployments of over 100 units in North America, as the market moves from shorter to longer duration energy storage, Norton said, it identified a further opportunity.

“So we invested in (Sun Catalyx), a technology that’s a spinout of MIT, to create a co-ordinated compound chemistry flow battery, that is human- and environmentally-safe, that is balance-of-plant cost-effective and that is deployable worldwide,” Dan Norton said.

Projects could be ‘multiple megawatts to hundreds of megawatts’
Long-duration flow batteries offer a potential to decouple energy and power, meaning that while they tend to cost more upfront than lithium-ion batteries, they can effectively scale up fairly easily, simply by increasing the capacity of the tanks the electrolyte is pumped through. While the small handful of flow battery companies already out there in the market tend to favour either vanadium or zinc bromine, Lockheed is keeping tight-lipped still on the makeup of the proprietary electrolyte its GridStar Flow products will use.