Energy Storage Stocks

Tesla

Tesla's Energy Generation & Storage segment centres on Megapack, a utility-scale containerised BESS combining lithium-ion modules, power electronics, and Autobidder optimisation software, deployed in multi-gigawatt-hour arrays globally. The segment deployed **46.7 GWh** in FY2025 (+49% YoY) and generated **$12.77 billion** in revenue at a 29.8% gross margin — the fastest-growing and highest-margin of Tesla's two reportable segments. Manufacturing spans Megafactory Lathrop (40 GWh, California), Megafactory Shanghai (20 GWh, operational since early 2025), and a new Houston Megafactory under construction for the next-generation Megapack 3 / Megablock. Ramping domestic LFP cell production at Gigafactory Nevada, cathode localisation, and an in-house lithium refinery (operational since January 2026) underpin a structural cost reduction trajectory as vertical integration deepens. Tariff exposure is flagged by management as a larger headwind for Energy than for Automotive, and quarterly deployments are lumpy — Q1 2026 was 8.8 GWh, down 15% YoY on project timing.

CATL

Contemporary Amperex Technology Co. Limited (CATL, 300750.SZ) is the world's largest battery manufacturer, holding **39.2% global EV battery market share** in 2025 and ranking #1 in energy storage battery shipments for five consecutive years (2021–2025). Total battery sales reached 661 GWh in FY2025 (+39% YoY), of which approximately 121 GWh were ESS batteries generating RMB 62.4 billion in revenue (+9% YoY). ESS product launches include the **TENER Stack** (9 MWh per system, the world's first mass-producible ultra-large capacity ESS unit) and a 6.25 MWh containerised liquid-cooled BESS with 30% higher energy density than its predecessor. The company's Tianhe platform targets long-duration storage beyond standard LFP. A Hungary factory is under construction for international supply, and a secondary Hong Kong listing (3750.HK) provides offshore investor access. CATL competes across both cell supply and complete BESS integration against BYD and Sungrow, with overseas gross margins running materially above the domestic market at 31.4% in FY2025.

BYD Company

BYD Company Limited (1211.HK) is the world's top-selling NEV manufacturer and a globally leading battery group, with an energy storage division that shipped more than **60 GWh of ESS in FY2025** — ranking #1 globally. The company's MC Cube-T liquid-cooled BESS and proprietary LFP Blade Battery are deployed across utility-scale projects worldwide; the standout contract is a **12.5 GWh supply to Saudi Electricity Company**, the world's largest single grid-scale storage project at signing, with delivery commencing April 2025. Deep vertical integration — spanning lithium, cell chemistry (BYD developed its proprietary LFP Blade Battery), pack assembly, and system integration — provides structural cost advantages over Western integrators. BYD's H-share listing (1211.HK) and Shenzhen A-shares (002594.SZ) provide domestic and international investor access, with US ADRs (BYDDY) also available. Group gross margin of 17.74% in FY2025 reflects intense domestic NEV pricing competition, while overseas sales carry materially higher margins.

LG Energy Solution

LG Energy Solution (LGES, 373220.KS) is one of the world's largest battery manufacturers, listed on the Korea Exchange after a January 2022 IPO and majority-owned by LG Chem. The company supplies pouch, cylindrical, and prismatic lithium-ion cells across EV and energy storage applications, and is the only global manufacturer producing all three formats at scale. Its ESS order backlog reached **140 GWh** at end-2025, reflecting rapid demand growth; North American ESS production capacity is targeted at 60+ GWh by end-2026, up from 12 GWh at end-2024. LGES benefits directly from the US IRA Section 45X Advanced Manufacturing Production Credit (NAPI), which contributed approximately KRW 1.65 trillion in FY2025 — without which the company ran an operating loss on an underlying basis, underscoring the policy dependency investors should monitor. FEOC-compliant US and South Korean manufacturing is a structural competitive advantage in markets seeking non-Chinese supply chains.

Sungrow

Sungrow Power Supply Co., Ltd. (300274.SZ) is the world's largest PV inverter supplier by shipments and one of the world's largest BESS integrators by deployed capacity, with energy storage growing to contribute approximately one-third of group revenue at 36.7% gross margins in FY2024. The company's liquid-cooled BESS product line — combining proprietary power conversion systems, battery packs, thermal management, and controls — is deployed globally for utility-scale, C&I, and residential storage, with Sungrow among the largest BESS suppliers across North America, Europe, the Middle East, and Asia. Its integrated PCS-plus-BESS offering competes directly with Tesla Megapack and Fluence, with competitive pricing and proven reliability enabling rapid international expansion. The Shenzhen-listed company has near-equal domestic and overseas sales, with international margins running materially higher than in the hyper-competitive domestic market.

Samsung SDI

Samsung SDI Co., Ltd. (006400.KS) is a South Korea-based battery manufacturer producing NCA and LFP prismatic cells, 46-series cylindrical cells, and electronic materials, serving EV, grid storage, and consumer electronics markets. Its ESS business — sold under the Samsung Battery Box (SBB) brand — achieved its highest-ever quarterly revenue in Q4 2025, with ESS revenue expected to grow close to 50% year-over-year in 2026 on the back of US local production ramp-up. Samsung SDI is one of the few major non-Chinese prismatic battery manufacturers, a structural advantage in FEOC-sensitive US procurement. FY2025 group results were deeply challenged: revenue fell 20% YoY to KRW 13.27 trillion and the company posted an operating loss of KRW 1.72 trillion, driven by weak EV demand from a key US customer and tariff headwinds on Korean-made ESS exports. The strategic pivot to US-local ESS production (StarPlus Energy JV with Stellantis in Indiana, plus LFP lines due Q4 2026), AMPC credits, and a joint development agreement with BMW on all-solid-state batteries define the medium-term recovery thesis.

Wärtsilä

Wärtsilä Corporation (WRT1V.HE, Nasdaq Helsinki) is a Finnish marine and energy technology group founded in 1834, delivering power plant engines, battery energy storage systems, and lifecycle services across more than 180 countries. Its **Energy Storage** segment — a discrete reportable division — generated EUR 694 million in net sales and EUR 24 million in comparable operating profit (3.4% margin) in FY2025, deploying systems including the 200 MW / 400 MWh Blackhillock project in the UK (one of Europe's largest grid-scale storage systems, named a TIME Magazine Best Invention of 2025) and what will become the largest BESS facility in the southern hemisphere at Origin's Eraring site in Australia. Wärtsilä pairs hardware with its **GEMS Digital Energy Platform** and the **Quantum BESS** product portfolio. Critical caveat: Energy Storage order intake was **EUR 0 million** in Q1 2026 (vs. EUR 30 million in Q1 2025) due to US tariffs on Chinese-sourced components and FEOC regulatory changes — management warned that without a significant improvement in order intake, the segment will incur losses in H2 2026. FY2025 group revenue was EUR 6.91 billion (+7% YoY) with a 12.0% comparable operating margin; the Energy and Marine segments are the primary earnings drivers.

EVE Energy

EVE Energy Co., Ltd. (300014.SZ) is a Huizhou-based lithium-ion battery manufacturer specialising in large-format cylindrical and prismatic cells for stationary energy storage, with a global leadership position in 46-series large cylindrical cells used in next-generation EV and grid storage systems. EVE is a major cell supplier to BESS integrators including Sungrow, and has established a strategic partnership with BMW for automotive-grade cylindrical cell supply, validating technology quality for demanding applications. The company operates multiple manufacturing sites in China with capacity expansion plans targeting key export markets, and competes in stationary storage alongside CATL and BYD through competitive LFP pricing and cell format innovation. EVE's positioning at the intersection of 46-series cylindrical technology and grid storage sets it apart from peers competing primarily in prismatic LFP, creating optionality across next-generation battery formats.

Gotion High-Tech

Gotion High-Tech Co., Ltd. (002074.SZ) is a Hefei-based lithium-ion battery manufacturer producing LFP and NCM prismatic cells for energy storage systems and EVs, with Volkswagen as a strategic shareholder providing European OEM access and capital credibility beyond typical domestic Chinese players. Gotion has one of the most aggressive international manufacturing strategies among second-tier Chinese battery producers, with a greenfield gigafactory in Manteno, Illinois targeting US IRA Section 45X manufacturing credits alongside planned European capacity — though the incentive outcome remains highly policy-sensitive given FEOC rules and the company's Chinese ownership. The company competes on cost with CATL and BYD while differentiating through manufacturing localisation in Western markets and the VW partnership for OEM battery supply. For investors, Gotion offers a proxy on Chinese battery manufacturing internationalisation at a valuation discount to top-tier peers.

CALB

China Aviation Lithium Battery Co., Ltd. (CALB, 3931.HK) is one of China's largest lithium-ion battery manufacturers, originally founded as a state-backed aerospace battery supplier and expanded aggressively into grid-scale BESS supply, delivering LFP prismatic cells and battery modules to major storage integrators in China and internationally. CALB operates multiple gigafactories across China with strong domestic utility-scale BESS contracts underpinned by state-coordinated grid storage buildout, and raised international capital through a Hong Kong IPO to accelerate manufacturing growth. The company competes directly with CATL, BYD, EVE, and Gotion in domestic stationary storage supply while targeting international BESS integrators in Asia, Europe, and the Middle East. For investors, CALB offers exposure to one of China's top-tier battery manufacturers with strong grid storage concentration at a significant valuation discount to CATL.

Fluence Energy

Fluence Energy (FLNC, NASDAQ) is a utility-scale BESS integrator and digital platform company formed as a 50/50 JV between Siemens and AES in 2017 and listed in November 2021; AES Grid Stability (28%) and Siemens remain major shareholders. FY2025 (ended September 30, 2025) revenue was **$2,263M** with a contracted solutions backlog of **$5.5 billion (record, as of Q1 FY2026)** and 6.8 GW of energy storage deployed across 33 markets in 25 countries. Products include Gridstack Pro (large-scale FTM), Ultrastack (synthetic inertia), and the new Smartstack (7.5 MWh modular). Revenue is heavily weighted to H2; management guides ~1/3 in H1 and ~2/3 in H2 with negative Adjusted EBITDA in H1 FY2026. Annual Recurring Revenue (ARR) was $154M at December 31, 2025, targeting ~$180M by end of FY2026. Fluence is the most direct pure-play Western BESS integrator on a major US exchange, benefiting from FEOC-sensitive US procurement — but customer concentration is high, with two customers at ~41% of FY2025 revenue.

Eos Energy Enterprises

Eos Energy Enterprises (EOSE, NASDAQ) designs and manufactures Znyth™ zinc-based battery systems for 4-to-16+ hour long-duration energy storage, manufactured entirely in the US across three Pennsylvania facilities (annualised capacity of 2 GWh at end-2025, targeting 4 GWh by end-2026). The Znyth™ chemistry is zinc-based aqueous electrolyte — non-flammable, with no lithium or cobalt — and is designed for >15,000 cycles. FY2025 revenue was $114.2M with a gross margin of negative 126%, an improvement from negative 534% in FY2024; the path to positive gross margin is predicated on manufacturing automation and scale. Contracted backlog at end-2025 was $701.5M / 2.8 GWh across 18 customers in 10 US states, with a commercial pipeline of $23.6 billion / 99 GWh. Eos raised $1.06 billion in November 2025 (stock + convertible notes), ending 2025 with $624.6M total cash (including restricted cash). ⚠️ **Distress note:** Despite the cash position, shareholders' equity is deeply negative at $(2.24B); a securities class action (lead-plaintiff deadline May 5, 2026) alleging misrepresentations about revenue and battery production was pending; and the company remains pre-profitability. Treat as high-risk, pre-commercial-scale.

Energy Vault Holdings

Energy Vault Holdings (NRGV, NYSE) has evolved well beyond its original gravity storage identity into a vertically integrated energy infrastructure company — delivering BESS projects, developing and owning storage assets under long-term contracts, and pursuing AI data-centre power infrastructure. FY2025 revenue was **$203.6M** (~96% from BESS EPC/EEQ delivery), with two operating assets: Cross Trails BESS (57 MW / 114 MWh, ERCOT, 10-year offtake) and Calistoga Resiliency Center (8.5 MW / ~293 MWh, CAISO, PG&E agreement). Under-construction projects include Stoney Creek (125 MW / 1 GWh, 8-hour, Australia) and SOSA Energy Center (150 MW, Texas). The company is also developing modular AI data-centre infrastructure co-located with storage (Crusoe partnership) and a Japan BESS portfolio (850 MW pipeline acquired Q1 2026). Gravity storage (EVx) technology remains in the portfolio but is no longer the primary commercial driver. Revenue is highly concentrated: two customers accounted for 88% of FY2025 revenue. High risk, pre-contracted-revenue-diversification stage.

Invinity Energy Systems

Invinity Energy Systems (IES.L, AIM) is a UK-listed manufacturer of vanadium redox flow battery systems for long-duration grid-scale energy storage, with production facilities in the UK and Canada and deployments across Europe, North America, and Asia. The company's current product range, led by the **Endurium** and **Endurium Enterprise** systems, delivers 6-to-12-hour discharge duration with unlimited cycle life, non-flammable chemistry, and a 25-year calendar life — advantages that make VRFB technology increasingly attractive as grids require extended storage to balance growing solar and wind penetration. Invinity is one of the world's foremost dedicated VRFB manufacturers and a primary listed exposure to vanadium flow battery technology, pursuing manufacturing scale and cost reduction to narrow the cost gap with lithium-ion for multi-hour applications.

Largo Inc.

Largo Inc. (LGO, TSX/Nasdaq) is a Canada-listed critical materials company whose primary business is vanadium and ilmenite production from the Maracás Menchen mine in Brazil — one of the world's highest-grade vanadium deposits. Largo supplies vanadium pentoxide to the global steel industry and vanadium electrolyte to battery manufacturers. Its energy storage exposure comes through Storion Energy (formerly VCHARGE+), a subsidiary developing vanadium redox flow battery systems — but VRFB commercialisation is a strategic minority activity, not the current revenue driver. FY2025 results were materially impacted by weaker vanadium prices. For investors, Largo is best understood as a vanadium commodity producer with long-duration storage optionality, not a scaled VRFB technology deployer.

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Stem Inc.

Stem, Inc. (STEM, NYSE) is a clean energy software and services company that pivoted away from battery hardware resale in October 2024 to focus on its **PowerTrack** platform — solar monitoring, analytics, and storage optimisation software deployed across 37.5 GW of solar assets under management and approximately 1.7 GWh of storage AUM as of Q1 2026. FY2025 PowerTrack software revenue was $37.7M (+15% YoY) at a 65% gross margin; Annual Recurring Revenue was $61.2M at Q1 2026. The hardware pivot involved a ~27% workforce reduction in April 2025 and battery hardware resale reaching zero in Q1 2026 (though up to $40M remains in H2 2026 guidance on an opportunistic basis). The company operates across 55+ countries and holds 13 of the top 15 commercial/industrial solar asset owners as customers. ⚠️ **Financial note:** Stem has posted consistent operating losses through the transition; the managed services segment runs at negative GAAP gross margin (-8% in Q1 2026). The strategic pivot narrows the investment thesis to pure software/services growth from a still-subscale ARR base.

ESS Tech

ESS Tech, Inc. (GWH, NYSE) designs and manufactures iron flow batteries using iron, salt, and water — a non-flammable, earth-abundant chemistry targeting 10-to-22-hour long-duration grid storage. The current commercial product is the **Energy Base**, a gigawatt-hour-scale open-architecture system (the Energy Warehouse and Energy Center generation products are largely superseded). FY2025 revenue was $1.6M (vs. $6.3M in FY2024) with a gross loss of $27.7M and net loss of $63.4M; the company burns approximately $50M of cash per year from operations. The flagship forward project is **Project New Horizon** — a 5 MW / 50 MWh pilot for Salt River Project and Google in Arizona, with manufacturing starting 2026 and delivery targeted December 2027. Cash at end-2025 was $22M total liquid assets. ⚠️ **Distress / Going Concern:** KPMG issued a going-concern opinion on the FY2025 10-K. NYSE issued a deficiency notice in March 2025 (market cap below $50M minimum); the NYSE accepted a remediation plan in August 2025 with an 18-month cure period. ESS Tech is pre-commercial-scale with acute liquidity risk — treat as venture/speculative.