ClearSign Technologies CLIR

NASDAQ CLIR

$4.22 -0.17 (-3.83%)

As of: Sep 9, 2026 · 2:16 PM EDT

Key Stats

Market Cap25.03 Mn

P/E-4.14

P/S4.59

Div. Yield0.00

Revenue Growth (1y) (Qtr)321.05

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About

ClearSign Technologies Corp designs and develops technologies for decarbonization and improving key performance characteristics of combustion systems, including emission and operational performance, energy efficiency, and overall cost effectiveness. The company’s ClearSign Core™ technology has been validated in full scale industrial test furnaces and boilers, with early customer installations now operating in normal commercial service. ClearSign Technologies Corp has generated nominal revenues to date while incurring losses since inception that total $104.2 million. To fund its operations, the firm has relied primarily on equity offerings, having raised approximately $105.3 million in gross proceeds through the sale of its securities as of September 30, 2025. The company maintains a workforce of 16 full time employees and supplements internal expertise with external consultants for specialized development and administrative tasks.

The company generates revenue primarily through the sale of spare parts, flare systems, midstream equipment, burner shipments, engineering services, and computational fluid dynamics (CFD) analysis to industrial customers. In the nine months ended September 30, 2025, revenue totaled $1,563 thousand, driven by spare parts orders, flare orders, midstream orders, and engineering services, while the comparable period in 2024 featured burner shipments to a California refinery, engineering feasibility studies, and additional spare parts deliveries. Revenue is recognized upon delivery of products or completion of services, and the firm also derives income from customer witness tests and related technical support. The firm’s revenue streams are project based and vary with the timing of customer orders and the completion of development milestones.

ClearSign Technologies Corp operates in the market for low emission combustion and energy efficiency solutions, where it seeks to differentiate itself through the proven performance of its ClearSign Core™ technology in reducing pollutants and improving fuel usage. The company competes with other providers of combustion and emissions control technologies, and its success depends on gaining market acceptance and achieving sufficient recurring sales to cover operating costs. Regulatory pressure to lower greenhouse gas emissions and improve industrial efficiency creates demand for technologies that can enhance furnace and boiler performance while reducing fuel consumption. ClearSign Core™ has demonstrated in full scale testing the ability to lower nitrogen oxide emissions and increase thermal efficiency, providing a potential advantage over conventional combustion systems.

The company serves a diverse industrial customer base that includes a California refinery, various processors requiring spare parts and flare equipment, midstream operators, and firms seeking engineering and CFD analysis services. Specific customers referenced in the filing consist of the California refinery that received burner shipments in 2024, while other engagements are described only in generic terms. ClearSign Technologies Corp also works with industrial firms that conduct witness tests to validate technology performance under real world conditions. The firm’s customer relationships are typically tied to individual projects, with repeat business contingent on demonstrated performance and cost benefit outcomes.

Investment Thesis

▲ Bull case

ClearSign's recent 26-burner order for a Gulf Coast petrochemical plant represents a significant validation of its technology's cost advantage over traditional SCR systems, with the company estimating savings of approximately $40 million for the client compared to the alternative solution. This order, driven by the need to meet stringent emissions regulations in Texas and California, underscores the compelling economic value proposition that positions ClearSign as a disruptive force in industrial combustion. The fact that the client chose ClearSign's solution despite the higher upfront perception of new technology adoption highlights strong trust in the company's ability to deliver both compliance and operational efficiency, which could accelerate adoption across similar facilities seeking to minimize total cost of ownership while meeting regulatory demands.
The company's collaborative partnership with Zeeco provides a critical asset-light manufacturing and testing infrastructure that eliminates the need for ClearSign to invest heavily in capital-intensive production facilities. Zeeco's status as a multibillion-dollar company with global manufacturing capabilities, including the world's largest burner test facility in Tulsa, ensures scalable production without constraining ClearSign's growth. This arrangement allows ClearSign to focus resources on innovation and sales while leveraging Zeeco's accredited quality control systems to gain customer acceptance, particularly important in an industry where equipment reliability and certification are paramount for adoption by major refiners and chemical companies.
ClearSign's technology demonstrates dual value beyond emissions reduction by improving heater operational efficiency, reducing hotspots, extending tube life, and increasing uptime—directly translating to maintenance cost savings and higher productivity for clients. This additional return on investment, particularly evident in projects like the 32 and 36 burner orders where clients seek performance enhancements alongside compliance, expands the addressable market beyond regulatory-driven replacements to include efficiency-focused upgrades. The ability to deliver both environmental and economic benefits creates a stronger incentive for adoption, especially in periods of capital allocation scrutiny where projects must justify spend through multiple value streams.
The addressable market opportunity is substantially larger than currently appreciated, with ClearSign estimating approximately 28,000 burners in Texas and California refineries alone, of which 15% (4,200 burners) are viable targets based on ExxonMobil's assessment. At an average price of $100,000 per burner, this represents a $420 million opportunity in the refining segment before considering petrochemical, midstream, flare, and thermal oxidizer applications. The company's success in adapting its burner technology to horizontal and flat configurations through recent orders opens new verticals like ethylene manufacturing, which Colin Deller noted is about the same size as the refining industry, suggesting a total addressable market potentially exceeding $840 million for core burner products.
The proposal backlog continues to grow meaningfully, with ClearSign having quoted 4 of 10 heater projects referred by Wahlco from a major refiner, totaling approximately 73 burners, and a overall quoted backlog of around 225 burners from household-name refiners. This pipeline, built on increased trust and visibility from completed projects like the 26-burner Gulf Coast order, indicates strong conversion potential as these projects move through engineering, testing, and installation phases. The lumpy revenue pattern acknowledged by management reflects the long sales cycles typical in industrial capital projects, but the increasing volume and quality of inquiries signal a maturing sales pipeline that could lead to more predictable and growing revenue streams as conversion rates improve.

ClearSign's recent 26-burner order for a Gulf Coast petrochemical plant represents a significant validation of its technology's cost advantage over traditional SCR systems, with the company estimating savings of approximately $40 million for the client compared to the alternative solution. This order, driven by the need to meet stringent emissions regulations in Texas and California, underscores the compelling economic value proposition that positions ClearSign as a disruptive force in industrial combustion. The fact that the client chose ClearSign's solution despite the higher upfront perception of new technology adoption highlights strong trust in the company's ability to deliver both compliance and operational efficiency, which could accelerate adoption across similar facilities seeking to minimize total cost of ownership while meeting regulatory demands.
The company's collaborative partnership with Zeeco provides a critical asset-light manufacturing and testing infrastructure that eliminates the need for ClearSign to invest heavily in capital-intensive production facilities. Zeeco's status as a multibillion-dollar company with global manufacturing capabilities, including the world's largest burner test facility in Tulsa, ensures scalable production without constraining ClearSign's growth. This arrangement allows ClearSign to focus resources on innovation and sales while leveraging Zeeco's accredited quality control systems to gain customer acceptance, particularly important in an industry where equipment reliability and certification are paramount for adoption by major refiners and chemical companies.
ClearSign's technology demonstrates dual value beyond emissions reduction by improving heater operational efficiency, reducing hotspots, extending tube life, and increasing uptime—directly translating to maintenance cost savings and higher productivity for clients. This additional return on investment, particularly evident in projects like the 32 and 36 burner orders where clients seek performance enhancements alongside compliance, expands the addressable market beyond regulatory-driven replacements to include efficiency-focused upgrades. The ability to deliver both environmental and economic benefits creates a stronger incentive for adoption, especially in periods of capital allocation scrutiny where projects must justify spend through multiple value streams.
The addressable market opportunity is substantially larger than currently appreciated, with ClearSign estimating approximately 28,000 burners in Texas and California refineries alone, of which 15% (4,200 burners) are viable targets based on ExxonMobil's assessment. At an average price of $100,000 per burner, this represents a $420 million opportunity in the refining segment before considering petrochemical, midstream, flare, and thermal oxidizer applications. The company's success in adapting its burner technology to horizontal and flat configurations through recent orders opens new verticals like ethylene manufacturing, which Colin Deller noted is about the same size as the refining industry, suggesting a total addressable market potentially exceeding $840 million for core burner products.
The proposal backlog continues to grow meaningfully, with ClearSign having quoted 4 of 10 heater projects referred by Wahlco from a major refiner, totaling approximately 73 burners, and a overall quoted backlog of around 225 burners from household-name refiners. This pipeline, built on increased trust and visibility from completed projects like the 26-burner Gulf Coast order, indicates strong conversion potential as these projects move through engineering, testing, and installation phases. The lumpy revenue pattern acknowledged by management reflects the long sales cycles typical in industrial capital projects, but the increasing volume and quality of inquiries signal a maturing sales pipeline that could lead to more predictable and growing revenue streams as conversion rates improve.

▼ Bear case

ClearSign's gross margin declined to 27% for the full year 2025 from 31% in 2024, a 4 percentage point drop primarily attributed to warranty accruals, which raises concerns about product reliability or underestimation of long-term performance costs. This margin compression occurred despite a 44% year-over-year revenue increase driven by the large 26-burner order, suggesting that profitability may not scale linearly with revenue growth if warranty costs remain elevated or if product mix shifts toward lower-margin offerings. Persistent margin pressure could undermine the company's path to breakeven and profitability, especially given its stated need for approximately $16 million in annual revenue to reach that milestone, as any sustained margin erosion would require even higher sales volumes to achieve the same profit level.
The company's net loss increased by approximately $197,000 year-over-year in 2025, driven largely by nonrecurring legal fees of $746,000, which introduces uncertainty about the sustainability of expenses and potential for similar one-time costs to reoccur. While management characterized these fees as nonrecurring, the lack of detail about their nature or origin leaves investors unable to assess whether such expenses are truly anomalous or indicative of underlying legal, regulatory, or contractual risks that could resurface. This opacity around significant expense items complicates financial forecasting and risk assessment, particularly for a company still operating at a loss and reliant on external funding or cash reserves to sustain operations.
Despite strong order announcements, revenue recognition remains tied to lengthy installation and commissioning timelines, as evidenced by the 26-burner order being recognized in Q4 2025 but not scheduled for start-up until October 2026, creating a significant gap between booking revenue and actual field deployment. This delay increases execution risk, as any issues during installation, performance shortfalls, or customer dissatisfaction could lead to order modifications, cancellations, or reputational damage that undermines the reference value management emphasizes. The reliance on future start-up events as catalysts for visibility and pipeline growth means near-term momentum is contingent on uncertain operational outcomes rather than contracted revenue alone.
ClearSign's dependence on third-party manufacturers like Zeeco for production and testing, while asset-light, introduces supply chain and partnership risk; any disruption in this relationship—whether due to Zeeco's shifting priorities, capacity constraints, or strategic realignments—could severely impair ClearSign's ability to fulfill orders. Although management highlighted Zeeco's global scale and Tulsa facilities, the company did not address contractual safeguards, exclusivity terms, or what would happen if Zeeco prioritized its own burner technology or faced internal challenges. This over-reliance on a single key partner for core manufacturing and validation creates a vulnerability that is not fully mitigated by the asset-light model's apparent advantages.
The addressable market assumptions, while expansive, rely heavily on regulatory enforcement in specific regions like Texas and California, with management acknowledging that emissions standards in the Middle East are not comparable and thus unlikely to drive near-term adoption there. This geographic concentration means ClearSign's growth is vulnerable to policy changes, enforcement delays, or economic downturns in its core markets that could slow refinery and petrochemical capital expenditures. Furthermore, the long adoption timeline referenced—10 years to retrofit the estimated 4,200 viable burners—implies that even under optimistic scenarios, meaningful revenue contribution from this pipeline will be gradual, potentially failing to meet near-term investor expectations for rapid scaling despite the large total addressable market cited.

ClearSign's gross margin declined to 27% for the full year 2025 from 31% in 2024, a 4 percentage point drop primarily attributed to warranty accruals, which raises concerns about product reliability or underestimation of long-term performance costs. This margin compression occurred despite a 44% year-over-year revenue increase driven by the large 26-burner order, suggesting that profitability may not scale linearly with revenue growth if warranty costs remain elevated or if product mix shifts toward lower-margin offerings. Persistent margin pressure could undermine the company's path to breakeven and profitability, especially given its stated need for approximately $16 million in annual revenue to reach that milestone, as any sustained margin erosion would require even higher sales volumes to achieve the same profit level.
The company's net loss increased by approximately $197,000 year-over-year in 2025, driven largely by nonrecurring legal fees of $746,000, which introduces uncertainty about the sustainability of expenses and potential for similar one-time costs to reoccur. While management characterized these fees as nonrecurring, the lack of detail about their nature or origin leaves investors unable to assess whether such expenses are truly anomalous or indicative of underlying legal, regulatory, or contractual risks that could resurface. This opacity around significant expense items complicates financial forecasting and risk assessment, particularly for a company still operating at a loss and reliant on external funding or cash reserves to sustain operations.
Despite strong order announcements, revenue recognition remains tied to lengthy installation and commissioning timelines, as evidenced by the 26-burner order being recognized in Q4 2025 but not scheduled for start-up until October 2026, creating a significant gap between booking revenue and actual field deployment. This delay increases execution risk, as any issues during installation, performance shortfalls, or customer dissatisfaction could lead to order modifications, cancellations, or reputational damage that undermines the reference value management emphasizes. The reliance on future start-up events as catalysts for visibility and pipeline growth means near-term momentum is contingent on uncertain operational outcomes rather than contracted revenue alone.
ClearSign's dependence on third-party manufacturers like Zeeco for production and testing, while asset-light, introduces supply chain and partnership risk; any disruption in this relationship—whether due to Zeeco's shifting priorities, capacity constraints, or strategic realignments—could severely impair ClearSign's ability to fulfill orders. Although management highlighted Zeeco's global scale and Tulsa facilities, the company did not address contractual safeguards, exclusivity terms, or what would happen if Zeeco prioritized its own burner technology or faced internal challenges. This over-reliance on a single key partner for core manufacturing and validation creates a vulnerability that is not fully mitigated by the asset-light model's apparent advantages.
The addressable market assumptions, while expansive, rely heavily on regulatory enforcement in specific regions like Texas and California, with management acknowledging that emissions standards in the Middle East are not comparable and thus unlikely to drive near-term adoption there. This geographic concentration means ClearSign's growth is vulnerable to policy changes, enforcement delays, or economic downturns in its core markets that could slow refinery and petrochemical capital expenditures. Furthermore, the long adoption timeline referenced—10 years to retrofit the estimated 4,200 viable burners—implies that even under optimistic scenarios, meaningful revenue contribution from this pipeline will be gradual, potentially failing to meet near-term investor expectations for rapid scaling despite the large total addressable market cited.

Product and Service Breakdown of Revenue (2018)

Peer group

Peer Comparison

Companies in the Pollution Control Equipment

S.No.	Ticker	Company	match	Market Cap	P/E	P/S	Total Debt (Qtr)
1	CECO	Ceco Environmental Corp	primary	3.38 Bn	-119.96	3.74	727.71 Mn
2	LNZA	LanzaTech Global, Inc.	primary	0.07 Bn	-1.22	1.25	12.70 Mn
3	FTEK	Fuel Tech, Inc.	primary	0.05 Bn	-15.05	1.92	-
4	SCWO	374Water Inc.	primary	0.04 Bn	-2.20	22.76	0.05 Mn
5	BCHT	Birchtech Corp.	primary	0.03 Bn	-7.47	1.35	-
6	CLIR	ClearSign Technologies Corp	primary	0.03 Bn	-4.14	4.59	-
7	LIQT	Liqtech International Inc	primary	0.01 Bn	-1.83	0.96	1.14 Mn
8	TOMZ	TOMI Environmental Solutions, Inc.	primary	0.01 Bn	-3.83	1.91	-

ClearSign Technologies CLIR

About

Investment Thesis

Product and Service Breakdown of Revenue (2018)

Peer Comparison

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