Other assets
Other assets consisted of the following at December 31, 2019 and 2018 (in thousands):
(1)    See Note 10. "Leases" to our consolidated financial statements for discussion of our lease arrangements.
(1)    (2)    In April 2009, we entered into a credit facility agreement with a solar power project entity of one of our customers for an available amount of €17.5 million to provide financing for a PV solar power system. The credit facility bears interest at 8.0% per annum, payable quarterly, with the full amount due in December 2026. As of December 31, 2019 and 2018, the balance outstanding on the credit facility was €7.0 million ($7.8 million and $8.0 million, respectively).
(3)    In June 2015, 8point3 Energy Partners LP (the “Partnership”), a limited partnership formed by First Solar and SunPower Corporation (collectively the “Sponsors”), completed its initial public offering (the “IPO”). As part of the IPO, the Sponsors contributed interests in various projects to OpCo in exchange for voting and economic interests in the entity, and the Partnership acquired an economic interest in OpCo using proceeds from the IPO.
In June 2018, we completed the sale of our interests in the Partnership and its subsidiaries to CD Clean Energy and Infrastructure V JV, LLC, an equity fund managed by Capital Dynamics, Inc. and certain other co-investors and other parties, and received net proceeds of $240.0 million after the payment of fees, expenses, and other amounts. We accounted for our interests in OpCo, a subsidiary of the Partnership, under the equity method of accounting as we were able to exercise significant influence over the Partnership due to our representation on the board of directors of its general partner and certain of our associates serving as officers of its general partner. During the year ended December 31, 2018, we recognized equity in earnings, net of tax, of $39.7 million from our investment in OpCo, including a gain of $40.3 million, net of tax, for the sale of our interests in the Partnership and its subsidiaries. During the year ended December 31, 2018, we received distributions from OpCo of $12.4 million.
In connection with the IPO, we also entered into an agreement with a subsidiary of the Partnership to lease back one of our originally contributed projects, Maryland Solar, until December 31, 2019. Under the terms of the agreement, we made fixed rent payments to the Partnership’s subsidiary and were entitled to all of the energy generated by the project. Due to certain continuing involvement with the project, we accounted for the leaseback agreement as a financing transaction until the sale of our interests in the Partnership and its subsidiaries in June 2018. Following the sale of such interests, the Maryland Solar project qualified for sale-leaseback accounting, and we recognized net revenue of $32.0 million from the sale of the project.
(4)    See Note 9. “Derivative Financial Instruments” to our consolidated financial statements for discussion of our derivative instruments.
Table:
 | 2019 | 2018
Operating lease assets (1) | $145,711 | $—
Indirect tax receivables . | 9,446 | 22,487
Notes receivable (2) | 8,194 | 8,017
Income taxes receivable . | 4,106 | 4,444
Equity method investments (3) . | 2,812 | 3,186
Derivative instruments (4) . | 139 | —
Deferred rent . | — | 27,249
Other . | 79,446 | 33,495
Other assets | $249,854 | $98,878


Question: When did 8point3 Energy Partners LP complete its initial IPO?
Answer: June 2015