ClearSign Technologies (NASDAQ:CLIR) outlined a sharp year-over-year revenue increase in 2025 and discussed progress on multiple large refinery and petrochemical burner projects during its fourth quarter and full-year 2025 corporate update call. Management emphasized growing customer engagement, expanded product configurations, and upcoming demonstrations intended to support additional order wins, while also cautioning that revenue is likely to remain “lumpy” as large projects move through phased engineering, testing, and manufacturing cycles.
2025 financial results highlighted by large process burner shipments
Chief Financial Officer Brent Hinds said ClearSign recognized approximately $3.7 million in revenue in the fourth quarter of 2025, compared with roughly $590,000 in the same period of 2024. Hinds attributed the increase predominantly to a $2.6 million process burner order that will be installed at a petrochemical plant on the Texas Gulf Coast.
Hinds reported full-year 2025 gross profit of approximately 27%, down from 31% in 2024, and said the decline was driven by a warranty accrual. He added that net loss increased by approximately $197,000 year over year, driven predominantly by “non-recurring legal fees of approximately $746,000 in 2025.”
On cash, Hinds said net cash used in operations was approximately $4.7 million in 2025 versus approximately $4.4 million in 2024. As of December 31, 2025, he said ClearSign had approximately $9.2 million in cash and cash equivalents and about 5.3 million shares of common stock outstanding.
Business model and market opportunity: ultra-low NOx burners and an asset-light structure
Chief Executive Officer Jim Deller described ClearSign as an industrial technology company focused on low-emissions industrial burners used in applications such as oil refineries, chemical plants, boilers, and midstream gas heaters. He said the market is driven by emissions regulations, particularly ultra-low NOx requirements, and positioned ClearSign’s approach as a cost-efficient alternative to selective catalytic reduction (SCR) systems because the company aims to reduce emissions formation inside the flame rather than removing emissions downstream.
As an example of the economic case, Deller said one customer estimated an SCR-based conversion project at about $50 million, while the ClearSign-based solution was estimated in the range of $7 million to $10 million, which he said represented roughly $40 million in savings on that project.
Deller also discussed the company’s assessment of potential market size, focusing on the most stringent U.S. regulatory regions. He estimated there are about 28,000 burners installed in refineries in California and Texas. Referencing a 2019 technology feasibility study with ExxonMobil, he said ExxonMobil assessed about 15% of its burners as good targets for ClearSign technology; applying that percentage to the installed base yields about 4,200 burners as potential retrofit candidates over roughly 10 years. Deller cited an average burner price of about $100,000 for estimation purposes and said the petrochemical industry is “about the same size as the refining industry.”
Deller added that ClearSign is “asset-light” and said the company needs a run rate of about $16 million per year, or about 160 process burners per year, to reach breakeven.
On commercialization, Deller highlighted ClearSign’s collaboration with Zeeco, which he described as a multi-billion-dollar company with extensive testing and manufacturing infrastructure. Under the arrangement, ClearSign leverages its intellectual property while Zeeco manufactures and supports testing for process burner products, helping satisfy customer requirements for accredited manufacturing and quality control.
Major process burner projects: installations, phased releases, and new configurations
Management said the 26-burner order that drove fourth-quarter revenue has been completed and delivered. Deller said the burners are currently on the customer’s site, with installation expected “early after mid-year” and startup currently expected in October. He called the project an important visibility and reference opportunity, noting the customer’s prominence in the Texas Gulf Coast market and involvement from heater engineering and revamp firm Calco.
ClearSign also discussed two additional announced process burner orders: a 36-burner order for a “household name” major customer on the Gulf Coast and a 32-burner order for another major refiner. Deller said both are released in phases, typically starting with engineering and CFD modeling. For the 36-burner project, he said engineering work has gone “extremely well,” and the company is discussing a move into testing. He added that the installation has been split into two phases and that the first manufacturing phase has been pulled forward, which he described as “very good news.”
Deller said the 36-burner project is not only about maintaining NOx compliance but also improving heater performance. He said ClearSign’s ability to control flame structure can improve heat transfer patterns, reduce hotspots, lower maintenance requirements, and increase uptime, providing a return on investment beyond emissions compliance.
He also said the 36-burner project involves a new configuration for ClearSign: horizontally fired burners mounted on opposed walls, expanding the company’s reference base into another heater type.
For the 32-burner order, Deller said engineering and CFD work has gone well and that the project is also split into two parts with an accelerated first portion. He said ClearSign has received an order for additional engineering to support testing and expects to move into the testing phase soon. He described this project as involving a “flat burner” configuration designed to fire against a wall inside the heater, noting that this style is relevant for many refinery heaters and could represent a step toward future participation in ethylene manufacturing furnaces.
Pipeline, demonstrations, and aftermarket opportunity
Deller said ClearSign has seen a shift in inquiries toward major and super-major customers and provided additional pipeline details. He said that from a set of 10 prospective heater projects discussed previously, ClearSign has so far received four inquiries and provided proposals, noting that timing depends on refinery turnarounds and project planning. He said those four heaters total about 73 burners.
On the broader process burner proposal pipeline, Deller said the company previously cited a total around 200 burners and that, with additional inquiries, he believes the total is “around 225 as we sit today,” coming from “household name” major refiners.
Deller also pointed to an upcoming industry demonstration of a new burner technology developed under a Department of Energy SBIR grant, scheduled for April 23 at Zeeco’s test facility. He said attendance has grown compared with prior demonstrations, with “just over 30 and counting” participants expected, including decision makers and subject matter experts from major refineries and engineering companies.
During Q&A, Water Tower Research Managing Director Peter Gastreich asked about how new burner configurations could expand addressable markets. Deller said the adaptability of the SBIR-developed platform is significant and estimated that the two new formats discussed could add “20%-25%” to ClearSign’s refining coverage. He added that the technology could also open the door to ethylene production, which he said is about the size of the refining industry.
Gastreich also asked about Zeeco’s capacity to support growth. Deller said Zeeco has global manufacturing capability and extensive test infrastructure, and he also pointed to additional manufacturing resources in Tulsa for other product lines.
On aftermarket potential, Deller said spare parts and service can become “extremely meaningful,” describing it as profitable due to limited incremental engineering and the importance of responsiveness. He said it could become one of the largest sources of income in terms of profit margin as more equipment is installed.
Other business lines: midstream burners and flares expand through partners and larger system sales
Deller described ClearSign’s midstream burner business as serving more standardized heater equipment, typically fueled by natural gas, which can result in shorter cycle times and lower engineering burden once products are developed. He said the company’s midstream proposal pipeline was “up 50” at the time of a prior update and continues to grow, while acknowledging that some quoting activity may occur without ClearSign’s direct visibility once customers have established pricing.
Deller said ClearSign’s M1 midstream burner has operated for months and achieved around 2 parts per million NOx, and that a lower-cost “M25” burner has now started up at another Devco heater in Texas and “met all requirements.” He also discussed a change in the channel landscape, noting Zeeco’s acquisition of Devco and saying both Zeeco and ClearSign confirmed that ClearSign burners would remain part of the business.
On flares, Deller described ClearSign’s products as enclosed, smaller flares designed for low emissions. He said earlier flare orders typically involved replacing burner elements in existing flare stacks and ran around $200,000 to $250,000 per burner order. More recently, he said customers have moved toward broader “system projects” that can include fuel control systems, blowers, and stack elements, with orders ranging from about $500,000 up to around $1 million; he said the most recent order was “right around” $1 million and represented the customer’s fifth order.
Deller said the company expects additional flare work from that customer, though timing is uncertain, and he also discussed a related opportunity in horizontal incinerators or thermal oxidizers, where ClearSign’s burners may reduce the need for supplemental natural gas in burning waste gases. He said the company has multiple projects quoted that it hopes will progress later in the year and noted potential renewables applications in the thermal oxidizer format.
Looking into 2026, management said key milestones include building backlog, securing additional orders, and delivering reference projects. Deller highlighted the October startup expectation for the 26-burner Texas Gulf Coast installation and the April 23 demonstration as near-term events intended to support further customer adoption.
Asked by H.C. Wainwright’s Amit Dayal about revenue cadence in 2026, Hinds said he does not expect first-quarter 2026 revenue to replicate the fourth quarter of 2025, while adding that management feels confident in 2026 revenue overall. Deller reiterated that revenue will likely remain uneven due to the size and duration of projects. On working capital, Deller said the company feels confident in its cash position and added that projects are “typically self-funding,” with customer payments arriving early enough to cover execution costs.
About ClearSign Technologies (NASDAQ:CLIR)
ClearSign Technologies Corporation is a clean energy technology company specializing in advanced combustion solutions that significantly reduce emissions of nitrogen oxides (NOx), carbon monoxide (CO), and greenhouse gases from industrial and power generation sources. Established in 2010 and based in Santa Rosa, California, ClearSign has developed proprietary burner and sensing platforms designed to enhance fuel efficiency and environmental performance for gas turbines, furnaces, boilers, and incineration units.
The company’s core offerings center around two technology platforms: the XCL™ ultra-low NOx combustion system and the SGM™ (Syngas & Gas Measurement) sensor suite.
