XML 35 R25.htm IDEA: XBRL DOCUMENT v3.25.2

Equity (Tables)

6 Months Ended

Jun. 30, 2025

Summary of warrants outstanding

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

Warrants

​

Pre-Funded Warrants(1)

(in thousands, except per share data)

​

Number

​

Wtd. Avg. Exercise Price

​

Wtd. Avg. Remaining Life (in years)

​

Aggregate Intrinsic Value

​

Number

​

Wtd. Avg. Exercise Price

​

Aggregate Intrinsic Value

Beginning Balance

​

21,295

$

1.0535

​

4.74

$

8,230

​

4,499

$

0.0001

$

6,478

Granted

​

—

​

—

​

​

​

​

​

—

​

—

​

​

Exercised

​

(23)

​

1.0500

​

​

​

​

​

(1,703)

​

0.0001

​

​

Forfeited/Expired

​

—

​

—

​

​

​

​

​

—

​

—

​

​

Outstanding at Period End

​

21,272

$

1.0535

​

4.24

$

—

​

2,796

$

0.0001

$

1,565

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

(1) Pre-funded warrants have no expiration date and only expire when exercised in full.

​

​

Schedule of outstanding, reserved and authorized shares under share-based compensation plans

​

​	​	​	​	​
​	​	June 30,	​	December 31,
(in thousands)		2025		2024
Outstanding options and restricted stock units		3,474		3,316
Reserved but unissued shares under the Plan	​	1,692	​	1,858
Reserved but unissued shares at end of period		5,166		5,174

Schedule of stock option activity

​

​	​	​	​	​	​	​	​	​	​
​	​	June 30,
​	​	2025
(in thousands, except per share data)	​	Options to Purchase Common Stock	​	Weighted Average Exercise Price		​	Weighted Average Remaining Contractual Life (in years)	​	Aggregate Intrinsic Value
Outstanding at beginning of year		2,452	​	$	2.04		4.92	$	496
Granted		—	​	$	—		​	​	​
Exercised		—	​	$	—		​	​	​
Forfeited/Expired		(55)	​	$	2.56		​	​	​
Outstanding at end of period		2,397	​	$	2.03		4.18	$	—
Exercisable at end of period		1,872	​	$	1.70		3.78	$	—

Schedule of restricted stock unit activity

​

​	​	​	​	​	​	​	​
​	​	June 30,
​	​	2025
(in thousands, except per share data)	​	Number of Shares	​	Weighted Average Grant Date Fair Value		​	Weighted Average Contractual Life (in years) (1)
Nonvested at beginning of year		865	​	$	0.99	​	0.88
Granted		393	​	$	0.91	​	​
Vested		(121)	​	$	0.91	​	​
Forfeited	​	(60)	​	$	0.92	​	​
Nonvested at end of period		1,077	​	$	0.97	​	1.36

Schedule of share-based compensation activity

​

​	​	​	​	​
​	​	June 30,		​
(in thousands)		2025
Reserved but unissued shares at beginning of period	​	​	264	​
Increases in the number of authorized shares	​	​	21	​
Grants	​	​	(7)	​
Reserved but unissued shares at end of period	​		278	​

Restricted Stock Units

Schedule of compensation expense

​

​	​	​	​	​	​	​	​	​	​	​
​	For the Three Months Ended				​	For the Six Months Ended
​	June 30,				​	June 30,
(in thousands, except per share data)	2025		2024		​	2025			2024
Share-based compensation expense	$	34	$	306	​	$	66	$	342	​
Weighted average value per share	$	0.89	$	1.36	​	$	0.89	$	1.32	​

Equity Incentive Plan

Schedule of compensation expense

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

2025

​

2024

(in thousands, except per share data)

​

Number of Shares

Fair Value

​

Weighted Average per Share

​

Number of Shares

Fair Value

​

Weighted Average per Share

Fair value of stock payments in accrued compensation

​

326

​

$

279

​

$

0.85

​

307

​

$

326

​

$

1.06

Consultant Stock Plan

Schedule of compensation expense

​

​	​	​	​	​	​	​	​	​	​	​	​
​	For the Three Months Ended					​	For the Six Months Ended
​	June 30,					​	June 30,
(in thousands, except per share data)	2025			2024			2025			2024
Share-based compensation expense	$	3	​	$	3	​	$	7	​	$	6
Weighted average value per share	$	0.94	​	$	0.81	​	$	0.94	​	$	0.81

​

Non-Qualified Stock Option

Schedule of stock option activity

​

​	​	​	​	​	​	​	​	​	​
​	​	June 30,
​	​	2025
(in thousands, except per share data)	​	Options to Purchase Common Stock	​	Weighted Average Exercise Price		​	Weighted Average Remaining Contractual Life (in years)	​	Aggregate Intrinsic Value
Outstanding at beginning of year		491	​	$	1.53		3.04	$	119
Granted		—	​	$	—		​	​	​
Exercised		—	​	$	—		​	​	​
Forfeited/Expired		—	​	$	—		​	​	​
Outstanding at end of period		491	​	$	1.53		2.55	$	—
Exercisable at end of period		441	​	$	1.60		2.79	$	—

X

- Definition

Summary of warrants outstanding.

+ References

No definition available.

+ Details

Name:	clir_SummaryOfWarrantsOutstandingTableTextBlock
Namespace Prefix:	clir_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Tabular disclosure of share-based payment arrangement.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

+ Details

Name:	us-gaap_DisclosureOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTextBlock
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Tabular disclosure of cost recognized for award under share-based payment arrangement by plan. Includes, but is not limited to, related tax benefit.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

+ Details

Name:	us-gaap_ScheduleOfCompensationCostForShareBasedPaymentArrangementsAllocationOfShareBasedCompensationCostsByPlanTableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Tabular disclosure of activity for award under share-based payment arrangement. Includes, but is not limited to, outstanding award at beginning and end of year, granted, exercised, forfeited, and weighted-average grant date fair value.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (d)
-SubTopic 10
-Topic 718
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (e)
-SubTopic 10
-Topic 718
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

+ Details

Name:	us-gaap_ScheduleOfShareBasedCompensationActivityTableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Tabular disclosure of the number and weighted-average grant date fair value for restricted stock units that were outstanding at the beginning and end of the year, and the number of restricted stock units that were granted, vested, or forfeited during the year.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

+ Details

Name:	us-gaap_ScheduleOfShareBasedCompensationRestrictedStockUnitsAwardActivityTableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Tabular disclosure for stock option plans. Includes, but is not limited to, outstanding awards at beginning and end of year, grants, exercises, forfeitures, and weighted-average grant date fair value.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (d)
-SubTopic 10
-Topic 718
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (e)
-SubTopic 10
-Topic 718
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

+ Details

Name:	us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_RestrictedStockUnitsRSUMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_PlanNameAxis=clir_EquityIncentivePlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_PlanNameAxis=clir_ConsultantPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_PlanNameAxis=clir_NonQualifiedStockOptionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: