Company Profile · Vanadium Flow Batteries Invinity’s next challenge is delivery, not discovery The listed battery manufacturer has operating experience and larger orders. Its Swiss megaproject remains a different proposition from its contracted equipment backlog. By CurrentCells Staff · October 20, 2026 AI-generated image Original editorial illustration, not a photograph or engineering rendering of an Invinity product or facility. Invinity Energy Systems is trying to build a manufacturing business around batteries that work hard for decades. Its vanadium flow systems target stationary energy storage, where repeated charging and discharging, serviceability and operating life can matter more than compactness. The opportunity is real, but the company's September 2026 interim results show how much still separates a proven technology from a consistently profitable supplier. The London-listed manufacturer reported 77.2 megawatt-hours of secured customer orders for the year to date, helped by a 43 MWh order from Dairyland Power Cooperative. It also reported a fleet that had dispatched 11 gigawatt-hours of electricity over time. At the same time, first-half revenue was only £1.1 million, and the loss for the six months ended June 30 was £12.1 million. Those figures describe a company scaling commercial delivery, not an established battery giant. The largest opportunity is in Switzerland. Invinity is designing a 1.5 GWh vanadium flow system for FlexBase's Laufenburg technology center, with a potential later expansion to 2.1 GWh. That project could change the company's scale. It should not be confused with an operating asset or treated as if its full battery capacity already sits inside the firm's unconditional orderbook. Company snapshot Business: vanadium flow battery manufacturing, integration and service for stationary storage. Public listing: London Stock Exchange's AIM market, ticker IES. Leadership: chief executive Jonathan Marren; chief financial officer Adam Howard. Manufacturing footprint: UK and Canadian factories, with a proposed U.S. manufacturing facility discussed in the September results. Main product: Endurium, a modular vanadium flow battery platform. Commercial question: whether lower product costs and larger orders can become repeatable deliveries, cash receipts and sustainable margins. A battery built around liquid electrolyte A vanadium flow battery stores energy in liquid electrolyte circulated through electrochemical stacks. The tanks hold the energy-bearing material, while the stacks convert chemical energy to electricity and back. That arrangement differs from lithium-ion batteries, where the energy storage and electrochemical conversion are closely integrated inside cells. The distinction gives flow batteries a different set of design choices. Tank volume and stack configuration influence energy capacity and power, respectively, although actual commercial products still come in defined configurations. Invinity's product page describes a 340 kWh Endurium module, factory preparation for installation and the ability to group units to meet project requirements. It also describes stacking units to make better use of a site's footprint. Invinity markets its systems around full depth of discharge, long asset life and high cycling capability. These are especially relevant when an owner wants a battery to move energy frequently rather than preserve a limited cycle budget. A solar installation shifting output into the evening, a grid-service operator and an industrial microgrid can have very different operating profiles, so the value of that flexibility depends on the actual duty cycle. The company's claims of a service life above 30 years are design and commercial propositions, not evidence that today's Endurium fleet has already completed three decades of service. Pumps, seals, controls, power electronics and other components still need maintenance. Buyers should distinguish durability of the storage chemistry from the availability and lifecycle cost of the entire installation. Safety comparisons need the same discipline. An aqueous vanadium electrolyte does not present the same combustible-cell thermal-runaway mechanism as lithium-ion. That does not remove electrical hazards, chemical handling requirements, containment engineering or site-specific permitting. Flow storage trades one engineering package for another; it does not eliminate engineering. Operating experience is becoming a commercial asset In an August operating update , Invinity said its installed VS3 and Endurium fleet had delivered more than 10 GWh of electricity to customers. The September interim report raised that cumulative figure to 11 GWh. The company identifies operating markets across the UK, continental Europe, North America, Australia and Southeast Asia. These numbers are useful, but their units can mislead a casual reader. Eleven gigawatt-hours dispatched is cumulative energy throughput, not 11 GWh of installed storage capacity. A much smaller battery fleet can deliver that quantity over many cycles. Throughput provides evidence of use; it does not by itself disclose the size, efficiency, availability or profitability of the fleet. The August update singled out the system at the Viejas Resort and Casino in California, installed by Indian Energy. Invinity said that installation had delivered more than 0.5 GWh since entering full operation and had met or exceeded warranted performance parameters. That is a company-reported operating reference, rather than an independently audited performance report reproduced in full. For a prospective customer, references still matter. A lender or engineering partner needs more than laboratory cycle data. It wants evidence that equipment can be manufactured, commissioned, operated and supported under real site conditions. Invinity now has a growing set of such references, although a project buyer should request the underlying availability, efficiency and maintenance records rather than infer them from aggregate throughput. The 20.7 MWh Copwood VFB Energy Hub in East Sussex illustrates another important distinction. The September results said delivery had been completed, while grid connection was expected shortly to enable full commissioning and first revenue generation. Delivery, grid connection and commercial operation are separate milestones. This profile does not assume that the later milestones occurred simply because equipment arrived. Endurium has to win on delivered economics Invinity is not competing against a static lithium-ion industry. Established battery suppliers have large manufacturing bases, mature integrator relationships and sustained pressure to reduce cost. A flow battery supplier therefore needs a credible case for the total cost of the service it provides, not merely an attractive description of its chemistry. Management's September report says Endurium's cost-reduction program remained on track for a minimum 66% product-cost reduction for 2027 deliveries versus previous generations. The report also describes earlier reductions over the VS3 product lifecycle. These are management's comparisons and targets. They should not be read as a universal installed-cost saving against lithium-ion or as a guarantee of a particular electricity price. Installed economics include civil works, power conversion, grid connection, controls, commissioning and finance. Operating economics include losses, maintenance, contracted availability and the price difference between charging and discharging periods. A supplier can reduce the cost of its battery modules while a difficult site still produces an expensive project. The first-half accounts show progress without establishing profitability. Gross loss narrowed to £0.7 million from £1.9 million in the comparable period. Invinity attributed the improvement to better product margins, lower warranty costs and higher absorption of manufacturing overhead. Yet the overall loss increased,