Note 11 - Subsequent Events	3 Months Ended
Mar. 31, 2020
Notes to Financial Statements
Subsequent Events [Text Block]	NOTE 11 — SUBSEQUENT EVENTS Cash Dividend On May 8, 2020, the Board of Directors of the Company declared, approved and authorized payment of a quarterly dividend of $5.6 million ($0.11 per share) to all holders of the Company’s issued and outstanding shares of common stock on May 21, 2020, payable on June 2, 2020. Senior Unsecured Bonds On April 6, 2020, the Company concluded an auction tender and accepted subscriptions for an additional aggregate principal amount of approximately $50 million of its Series 3 Senior Unsecured Bonds (the “Additional Series 3 Bonds”). The Additional Series 3 Bonds will mature in September 2022 and bear interest at a fixed rate of 4.45% per annum, payable semi-annually. The Additional Series 3 Bonds will be repaid at maturity in a single bullet payment, unless earlier prepaid by the Company pursuant to the terms and conditions of the trust instrument that governs such Senior Unsecured Bonds. Additionally, on April 20, 2020, the Company concluded an additional auction tender and accepted subscriptions for an aggregate principal amount of approximately $14.5 million under Series 3 Senior Unsecured Bonds (the “Second Addition to Series 3 Bonds”). The Second Addition to Series 3 Bonds will mature in September 2022 and bear interest at a fixed rate of 4.45% per annum, payable semi-annually. The Second Addition to Series 3 Bonds will be repaid at maturity in a single bullet payment, unless earlier prepaid by the Company pursuant to the terms and conditions of the trust instrument that governs such Senior Unsecured Bonds. Senior Unsecured Loan In April 2020, the Company entered into a second addendum (the “Second Addendum”) to the loan agreement with the Migdal Group dated March 22, 2018. The Second Addendum provides for an additional loan by the lenders to the Company in an aggregate principal amount of $50.0 million (the “Second Addendum Migdal Loan”). Of the Second Addendum Migdal Loan, $31.5 million will be repaid in equal 15 semi-annual payments commencing on September 15, 2021 and ending on September 15, 2028. The principal amount of the Second Addendum Migdal Loan of $18.5 million will be repaid in one bullet payment on March 15, 2029. The Second Addendum Migdal Loan bears interest at a fixed rate of 5.44% per annum, payable semi-annually, subject to adjustment in certain circumstances. The Second Addendum Migdal Loan was entered into under substantially the same terms and conditions of the Migdal Loan Agreement as disclosed above. COVID-19 related impact On April 17, 2020, the Company received from KPLC a notice declaring a force majeure event in Kenya due to the impact of COVID-19 and purporting to reduce the Olkaria complex’s contracted capacity from 150 MW to 133.9 MW. As a result of force majeure provisions in the Power Purchase Agreement related to this facility, the Company believes that the notice has an immaterial impact on its consolidated financial statements. Additionally, on April 30, 2020, the Company received from ENEE a notice declaring a force majeure event in Honduras due to the impact of COVID-19. The Company is currently evaluating the potential impact of this notice on its consolidated financial statements. Energy storage assets portfolio purchase transaction In April 2020, the Company amended the definitive agreements entered into in February 2020 to acquire a portfolio of energy storage assets in California from Alta Gas (the "Amended Agreements"). Under the Amended Agreements, the Company will acquire the Pomona 20MW battery storage facility from Alta Gas for a total consideration of $47 million. The transaction is contingent upon specific conditions related to the project as well as other customary closing conditions. Closing is is expected during the third quarter of 2020. The Company is currently evaluating the accounting impact of this transaction on its 2020 consolidated financial statements.

Note 11 - Subsequent Events

3 Months Ended

Mar. 31, 2020

NOTE 11 — SUBSEQUENT EVENTS

Cash Dividend

On May 8, 2020, the Board of Directors of the Company declared, approved and authorized payment of a quarterly dividend of $5.6 million ($0.11 per share) to all holders of the Company’s issued and outstanding shares of common stock on May 21, 2020, payable on June 2, 2020.

Senior Unsecured Bonds

On April 6, 2020, the Company concluded an auction tender and accepted subscriptions for an additional aggregate principal amount of approximately $50 million of its Series 3 Senior Unsecured Bonds (the “Additional Series 3 Bonds”). The Additional Series 3 Bonds will mature in September 2022 and bear interest at a fixed rate of 4.45% per annum, payable semi-annually. The Additional Series 3 Bonds will be repaid at maturity in a single bullet payment, unless earlier prepaid by the Company pursuant to the terms and conditions of the trust instrument that governs such Senior Unsecured Bonds.

Additionally, on April 20, 2020, the Company concluded an additional auction tender and accepted subscriptions for an aggregate principal amount of approximately $14.5 million under Series 3 Senior Unsecured Bonds (the “Second Addition to Series 3 Bonds”). The Second Addition to Series 3 Bonds will mature in September 2022 and bear interest at a fixed rate of 4.45% per annum, payable semi-annually. The Second Addition to Series 3 Bonds will be repaid at maturity in a single bullet payment, unless earlier prepaid by the Company pursuant to the terms and conditions of the trust instrument that governs such Senior Unsecured Bonds.

Senior Unsecured Loan

In April 2020, the Company entered into a second addendum (the “Second Addendum”) to the loan agreement with the Migdal Group dated March 22, 2018. The Second Addendum provides for an additional loan by the lenders to the Company in an aggregate principal amount of $50.0 million (the “Second Addendum Migdal Loan”). Of the Second Addendum Migdal Loan, $31.5 million will be repaid in equal 15 semi-annual payments commencing on September 15, 2021 and ending on September 15, 2028. The principal amount of the Second Addendum Migdal Loan of $18.5 million will be repaid in one bullet payment on March 15, 2029. The Second Addendum Migdal Loan bears interest at a fixed rate of 5.44% per annum, payable semi-annually, subject to adjustment in certain circumstances. The Second Addendum Migdal Loan was entered into under substantially the same terms and conditions of the Migdal Loan Agreement as disclosed above.

COVID-19 related impact

On April 17, 2020, the Company received from KPLC a notice declaring a force majeure event in Kenya due to the impact of COVID-19 and purporting to reduce the Olkaria complex’s contracted capacity from 150 MW to 133.9 MW. As a result of force majeure provisions in the Power Purchase Agreement related to this facility, the Company believes that the notice has an immaterial impact on its consolidated financial statements.

Additionally, on April 30, 2020, the Company received from ENEE a notice declaring a force majeure event in Honduras due to the impact of COVID-19. The Company is currently evaluating the potential impact of this notice on its consolidated financial statements.

Energy storage assets portfolio purchase transaction

In April 2020, the Company amended the definitive agreements entered into in February 2020 to acquire a portfolio of energy storage assets in California from Alta Gas (the "Amended Agreements"). Under the Amended Agreements, the Company will acquire the Pomona 20MW battery storage facility from Alta Gas for a total consideration of $47 million. The transaction is contingent upon specific conditions related to the project as well as other customary closing conditions. Closing is is expected during the third quarter of 2020. The Company is currently evaluating the accounting impact of this transaction on its 2020 consolidated financial statements.