Quarterly report [Sections 13 or 15(d)]

Cover
- Cover
Financial Statements
Notes to Financial Statements
Accounting Policies
- Description of business and basis of presentation (Policies)
Notes Tables
Notes Details

Stock-Based Compensation - Stock Option Activity (Details)

v3.25.1

Stock-Based Compensation - Stock Option Activity (Details) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2025	Dec. 31, 2024
Exercise Price Per Share [Abstract]
Exercise Price Per Share, Outstanding, Minimum (per share)	$ 0.71
Exercise Price Per Share, Outstanding, Maximum (dollars per share)	3.93
Exercise price per share, granted, minimum (in dollars per share)	$ 2.14
Certain Employees
Stock Options Outstanding [Roll Forward]
Granted (shares)	30,000
Tecogen
Stock Options Outstanding [Roll Forward]
Beginning (shares)	2,752,962
Granted (shares)	30,000
Exercised (shares)	(35,000)
Ending (shares)	2,747,962	2,752,962
Exercisable (shares)	1,805,462
Vested and expected to vest (shares)	2,606,587
Exercise Price Per Share [Abstract]
Exercise Price Per Share, Outstanding, Minimum (per share)		$ 0.71
Exercise Price Per Share, Outstanding, Maximum (dollars per share)		3.93
Exercise price per share, granted, maximum (in dollars per share)	$ 2.88
Exercise price per share, exercised (dollars per share)	1.10
Weighted Average Exercise Price [Roll Forward]
Beginning (usd per share)	1.14
Granted (usd per share)	2.32
Exercised (usd per share)	1.10
Ending (usd per share)	1.16	$ 1.14
Exercisable (usd per share)	1.26
Vested and expected to vest (usd per share)	$ 1.17
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Outstanding, Aggregate Intrinsic Value	$ 3,234,426	$ 1,348,684
Exercised, Aggregate Intrinsic Value	49,175
Exercisable, Aggregate Intrinsic Value	2,036,326
Vested and expected to vest, Aggregate Intrinsic Value	$ 3,054,711
Tecogen \| Stock Options
Weighted Average Exercise Price [Roll Forward]
Weighted Average Remaining Life	6 years 5 months 23 days	6 years 8 months 12 days

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The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

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Gross number of share options (or share units) granted during the period.

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Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

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Number of options outstanding, including both vested and non-vested options.

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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Amount by which current fair value of underlying stock exceeds exercise price of fully vested and expected to vest options outstanding. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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Number of fully vested and expected to vest options outstanding that can be converted into shares under option plan. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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Weighted-average exercise price, at which grantee can acquire shares reserved for issuance, for fully vested and expected to vest options outstanding. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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Weighted average price at which option holders acquired shares when converting their stock options into shares.

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Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

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