RELATED PARTY TRANSACTIONS	12 Months Ended
RELATED PARTY TRANSACTIONS	Dec. 31, 2022
Related Party Transactions [Abstract]
RELATED PARTY TRANSACTIONS	RELATED PARTY TRANSACTIONS The Company believes its transactions with related parties were conducted on terms equivalent to those prevailing in an arm's length transaction. Transactions with B. Riley Based on its Schedule 13D filings with the SEC, B. Riley beneficially owns 30.8% of our outstanding common stock as of December 31, 2022. B. Riley currently has the right to nominate one member of the Company’s board of directors pursuant to the investor rights agreement the Company entered into with B. Riley on April 30, 2019. The investor rights agreement also provides pre-emptive rights to B. Riley with respect to certain future issuances of the Company’s equity securities. The services of the Company’s Chief Executive Officer are provided by B. Riley pursuant to a consulting agreement with BRPI Executive Consulting, LLC, an affiliate of B. Riley, which was entered on November 19, 2018 and amended on November 9, 2020. The agreement provides for Mr. Kenny Young to serve as the Company’s Chief Executive Officer until December 31, 2023, unless terminated by either party with thirty days written notice. Under this agreement, payments are $0.75 million per annum, paid monthly. Subject to the achievement of certain performance objectives as determined by the Compensation Committee of the Board, a bonus or bonuses may also be earned and payable to BRPI Executive Consulting, LLC. B. Riley was a party to the Last Out Term Loans under our prior A&R Credit Agreement, as described in Note 15. Total fees associated with B. Riley related to the Last Out Term Loans and services of Mr. Kenny Young, both as described above, were $2.0 million, $0.8 million and $7.4 million for the twelve months ended December 31, 2022, 2021 and 2020, respectively. On November 13, 2020 the Company entered into an agreement with B. Riley Principal Merger Corp. II, an affiliate of B. Riley, to purchase 200,000 shares of Class A common stock of Eos Energy Storage LLC for an aggregate purchase price of $2.0 million. The shares were sold in January 2021 for which the Company recognized net proceeds of $4.5 million. The public offering of the Company's 8.125% Senior Notes in February 2021, as described in Note 14, was conducted pursuant to an underwriting agreement dated February 10, 2021, between the Company and B. Riley Securities, Inc., an affiliate of B. Riley, as representative of several underwriters. At the closing date on February 12, 2021, the Company paid B. Riley Securities, Inc. $5.2 million for underwriting fees and other transaction cost related to the 8.125% Senior Notes offering. The public offering of our common stock, as described in Note 18, was conducted pursuant to an underwriting agreement dated February 9, 2021, between the Company and B. Riley Securities, Inc., as representative of the several underwriters. Also on February 12, 2021, the Company paid B. Riley Securities, Inc. $9.5 million for underwriting fees and other transaction costs related to the offering. On February 12, 2021, the Company and B. Riley entered into the Exchange Agreement pursuant to which we agreed to issue to B. Riley $35.0 million aggregate principal amount of 8.125% Senior Notes in exchange for a deemed prepayment of $35.0 million of our existing Tranche A term loan with B. Riley Financial in the Exchange, as described in Note 14. On March 31, 2021, the Company entered into a sales agreement with B. Riley Securities, Inc., a related party, in which it may sell, from time to time, up to an aggregated principal amount of $150.0 million of 8.125% Senior Notes due 2026 to or through B. Riley Securities, Inc., as described in Note 14. As of December 31, 2022, we paid B. Riley Securities, Inc. $0.5 million for underwriting fees and other transaction costs related to the offering. The public offering of our 7.75% Series A Cumulative Perpetual Preferred Stock, as described in Note 17, was conducted pursuant to an underwriting agreement dated May 4, 2021, between the Company and B. Riley Securities, Inc., as representative of several underwriters. At the closing date on May 2021, the Company paid B. Riley Securities, Inc. $4.3 million for underwriting fees and other transaction cost related to the Preferred Stock offering. On May 26, 2021, the Company completed the additional sale of 444,700 shares of our Preferred Stock, related to the grant to the underwriters, as described in Note 17, and paid B. Riley Securities, Inc. $0.4 million for underwriting fees in conjunction with the transaction. On June 1, 2021, the Company issued 2,916,880 shares of the Company’s 7.75% Series A Cumulative Perpetual Preferred Stock and paid $0.4 million in cash due to B. Riley, a related party, in exchange for a deemed prepayment of $73.3 million of our then existing Last Out Term Loans and paid $0.9 million in cash for accrued interest, as described in Note 17. On June 30, 2021, the Company entered into new Debt Facilities, as described in Note 16. In connection with the Company’s entry into the Debt Facilities, B. Riley Financial, Inc., an affiliate of B. Riley, has provided a guaranty of payment with regard to the Company’s obligations under the Reimbursement Agreement, as describe in Note 16. Under a fee letter with B. Riley, the Company shall pay B. Riley $0.9 million per annum in connection with the B. Riley Guaranty. On July 7, 2021, the Company entered into a sales agreement with B. Riley Securities, Inc., a related party, in which the Company may sell, from time to time, up to an aggregated principal amount of $76 million of Preferred Stock to or through B. Riley Securities, Inc., as described in Note 17. As of December 31, 2022, the Company paid B. Riley Securities, Inc. $0.2 million for underwriting fees and other transaction costs related to the offering. The public offering of our 6.50% Senior Notes in December 2021, as described in Note 14, was conducted pursuant to an underwriting agreement dated December 8, 2021, between the Company and B. Riley Securities, Inc., an affiliate of B. Riley, as representative of several underwriters. At the closing date on December 13, 2021, the Company paid B. Riley Securities, Inc. $5.5 million for underwriting fees and other transaction cost related to the 6.50% Senior Notes offering. On December 17, 2021, B. Riley Financial, Inc. entered into a General Agreement of Indemnity (the "Indemnity Agreement"), between us and AXA-XL and or its affiliated associated and subsidiary companies (collectively the “Surety”). Pursuant to the terms of the Indemnity Agreement, B. Riley will indemnify the Surety for losses the Surety may incur as a result of providing a payment and performance bond in an aggregate amount not to exceed €30.0 million in connection with the Company's proposed performance on a specified project. In consideration of B. Riley's execution of the Indemnity Agreement, the Company paid B. Riley a fee of $1.7 million following the issuance of the bond by the Surety, which represents approximately 5.0% of the bonded obligations, to be amortized over the term of the agreement. On December 28, 2021, the Company received a notice that the underwriters of the 6.50% Senior Notes had elected to exercise its overallotment option for an additional $11.4 million in aggregate principal amount of the Senior Notes. At the closing date on December 30, 2021, the Company paid B. Riley Securities, Inc. $0.5 million for underwriting fees and other transaction cost related to the 6.50% Senior Notes overallotment. On July 20, 2022, BRF Investments, LLC, an affiliate of B. Riley, a related party exercised 1,541,666.7 warrants to purchase 1,541,666 shares of the Company's common stock at a price per share of $0.01 pursuant to the terms of the warrant agreement between the Company and B. Riley dated July 23, 2019. On July 28, 2022, the Company participated in the sale process of Hamon Holdings Corporation ("Hamon") for which B. Riley Securities, Inc., a related party to the Company, has been engaged as Hamon’s investment banker and to serve as advisor to Hamon through a Chapter 11 363 Asset Sale of Hamon’s entire United States business or potential carve-out of any of its four main subsidiaries. The Company was the successful bidder for the assets of one of those subsidiaries, Hamon Research-Cottrell, Inc., a major provider of air pollution control technology, for approximately $2.9 million.