Pay vs Performance Disclosure - USD ($)

12 Months Ended

36 Months Ended

Dec. 31, 2025

Dec. 31, 2024

Dec. 31, 2023

Dec. 31, 2025

Pay vs Performance Disclosure

Pay vs Performance Disclosure, Table

PAY VERSUS PERFORMANCE

We are providing the following information about the relationship between executive compensation actually paid (CAP) and certain financial performance of Fuel Tech as required by SEC rules. Please see Summary of Named Executive Officer Compensation, above for discussion of our compensation program.

Year	Summary Compensation Table Total for PEO(1)		Compensation Actually Paid to PEO(2)		Average Summary Compensation Table Total for Non-PEO NEOs (3)		Average Compensation Actually Paid to Non- PEO NEOs (4)		Value of Initial Fixed $100 Investment Based on Total Shareholder Return($) (5)		Fuel Tech Net Income (Loss) ($) (6)
2025		788,338		833,307		466,179		482,418		148.57		(2,324,000)
2024		449,483		316,312		354,629		307,981		82.68		(1,943,000)
2023		913,486		810,080		508,801		474,498		82.68		(1,538,000)

(1) Amounts shown reflect total compensation set forth in the Summary Compensation Table for our PEO, Mr. Arnone, for 2023, 2024 and 2025.

PEO Total Compensation Amount

$ 788,338

$ 449,483

$ 913,486

PEO Actually Paid Compensation Amount

$ 833,307

316,312

810,080

Adjustment To PEO Compensation, Footnote

(2) The following tables describes the adjustments, each of which is prescribed by SEC rule, to calculate the CAP amounts from the summary compensation table (SCT) amounts.

Compensation Actually Paid to PEO:

Year	Summary Compensation Table Total for PEO		Deduct Equity Awards (A)			Equity Award Adjustment (B)			Compensation Actually Paid to PEO
2025	$	788,338	$	(338,604	)	$	383,573		$	833,307
2024		449,483		—			(133,171	)		316,312
2023		913,486		(420,353	)		316,947			810,080

(A) Represents the amounts reported in the Equity Awards column in the Summary Compensation Table for the applicable year

(B) Represents the stock award adjustments (deductions and additions) for Non-PEO NEO stock awards for each applicable year calculated as follows:

PEO Equity Award Adjustment:

Year	Year-End Fair Value of Outstanding and Unvested Equity Awards Granted during the Year		Change in Fair Value of Outstanding and Unvested Equity Awards			Fair Value as of Vesting Date of Equity Awards Granted and Vested in the Year		Change in Fair Value of Equity Awards Granted in Prior Years that Vested in the Year		Fair Value at the End of the Prior Fiscal Year of Equity Awards that Failed to Meet Vesting Conditions During the Year			Total Equity Award Adjustments
2025	$	520,416		10,781			—		4,164		(151,788	)		383,573
2024		—		—			—		7,957		(141,128	)		(133,171	)
2023		350,280		(33,333	)		—		—		—			316,947

Non-PEO NEO Average Total Compensation Amount

$ 466,179

354,629

508,801

Non-PEO NEO Average Compensation Actually Paid Amount

$ 482,418

307,981

474,498

Adjustment to Non-PEO NEO Compensation Footnote

(3) Amounts shown reflect average total compensation set forth in the Summary Compensation Table for our NEOs, Ms. Albrecht and Mr. Cummings, for fiscal 2023, 2024 and 2025.

(4) The following tables describe the adjustments, each of which is prescribed by SEC rules to calculate the CAP amounts from the SCT amounts.

Average Compensation Actually Paid to Non-PEO NEO (all amounts are averages):

Year	Summary Compensation Table Total for Non-PEO NEO		Deduct Equity Awards (A)			Equity Award Adjustment (B)			Compensation Actually Paid to Non- PEO NEO
2025	$	466,179	$	(118,152	)	$	134,391		$	482,418
2024		354,629		—			(46,648	)		307,981
2023		508,801		(141,172	)		106,869			474,498

Average Non-PEO NEO Equity Award Adjustment:

Year	Year-End Fair Value of Outstanding and Unvested Equity Awards Granted during the Year		Change in Fair Value of Outstanding and Unvested Equity Awards			Fair Value as of Vesting Date of Equity Awards Granted and Vested in the Year		Change in Fair Value of Equity Awards Granted in Prior Years that Vested in the Year		Fair Value at the End of the Prior Fiscal Year of Equity Awards that Failed to Meet Vesting Conditions During the Year			Total Equity Award Adjustments
2025	$	182,280	$	3,796		$	—	$	1,459		(53,144	)		134,391
2024		—		—			—		2,880		(49,348	)		(46,648	)
2023		122,640		(15,771	)		—		—		—			106,869

(5) Amounts shown represent cumulative stockholder return assuming an initial investment of $100 on January 1, 2023.

(6) The amounts reported in this column represent net income (loss) reflected in the Company's audited financial statements for the applicable year.

Compensation Actually Paid vs. Company Selected Measure

Analysis of Information Presented in the Pay Versus Performance Table

We are providing the following descriptions of the relationships between information presented in the Pay Versus Performance table, including CAP, as required by Item 402(v) of Regulation S-K. The Compensation Committee does not use TSR or net income (loss) in its compensation programs. However, we do utilize several other performance measures to align executive compensation with our performance, see Executive Compensation.

● In fiscal 2023, compensation actually paid to the PEO equaled $810,080, and compensation actually paid to our non-PEO NEO’s averaged 474,498. These compensation levels are reflective of the elimination of the voluntary officer salary reduction program in the first half of 2023, the award of restricted stock units (subject to vesting contingent upon achieving performance conditions) pursuant to each officer’s 2023 Executive Performance RSU Agreement, a one-time cash bonus of $50,000 for Mr. Arnone and higher sales commission levels earned by Mr. Cummings. During this period, Fuel Tech’s common stock lost approximately 17% in value and Fuel Tech recorded an operating loss of ($1,538,000).

● In fiscal 2024, compensation actually paid to the PEO decreased by $493,768, or approximately 61 percent, and compensation actually paid to the non-PEO NEO’s decreased by $155,517, or approximately 33 percent. The decrease in compensation is primarily attributable to the failure to vest of 135,700 RSUs for our PEO and an average of 94,900 RSUs for our two non-PEO NEOs. During this period, Fuel Tech’s common stock remained the same in value ($1.04) and Fuel Tech recorded an operating loss of ($1,943,000).

● In fiscal 2025, Fuel Tech’s total stockholder return increased significantly to $149.99 (a 49.99% annual increase), while net loss increased to (2,324,000). The compensation actually paid to the PEO increased to $833,307 and the average compensation payable to the non-PEO NEO’s increased to $482,418. This compensation increases were primarily attributable to the award of restricted stock units (subject to vesting contingent upon achievement of performance conditions).

Total Shareholder Return Amount

$ 148.57

82.68

82.68

Net Income (Loss)

(2,324,000)

(1,943,000)

(1,538,000)

PEO Name

Mr. Arnone

PEO | Equity Awards Adjustments

Pay vs Performance Disclosure

Adjustment to Compensation, Amount

383,573

(133,171)

316,947

PEO | Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table

Pay vs Performance Disclosure

Adjustment to Compensation, Amount

(338,604)

0

(420,353)

PEO | Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested

Pay vs Performance Disclosure

Adjustment to Compensation, Amount

520,416

0

350,280

PEO | Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested

Pay vs Performance Disclosure

Adjustment to Compensation, Amount

10,781

0

(33,333)

PEO | Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year

Pay vs Performance Disclosure

Adjustment to Compensation, Amount

0

0

0

PEO | Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year

Pay vs Performance Disclosure

Adjustment to Compensation, Amount

4,164

7,957

0

PEO | Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year

Pay vs Performance Disclosure

Adjustment to Compensation, Amount

(151,788)

(141,128)

0

Non-PEO NEO | Equity Awards Adjustments

Pay vs Performance Disclosure

Adjustment to Compensation, Amount

134,391

(46,648)

106,869

Non-PEO NEO | Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table

Pay vs Performance Disclosure

Adjustment to Compensation, Amount

(118,152)

0

(141,172)

Non-PEO NEO | Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested

Pay vs Performance Disclosure

Adjustment to Compensation, Amount

182,280

0

122,640

Non-PEO NEO | Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested

Pay vs Performance Disclosure

Adjustment to Compensation, Amount

3,796

0

(15,771)

Non-PEO NEO | Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year

Pay vs Performance Disclosure

Adjustment to Compensation, Amount

0

0

0

Non-PEO NEO | Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year

Pay vs Performance Disclosure

Adjustment to Compensation, Amount

1,459

2,880

0

Non-PEO NEO | Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year

Pay vs Performance Disclosure

Adjustment to Compensation, Amount

$ (53,144)

$ (49,348)

$ 0