Sunnova Energy International's (NOVA) share price was tumbled 53% in Monday trading after the solar energy and storage company reported its year-end and Q4 earnings with a 'going concern' notice.

'Substantial doubt exists regarding our ability to continue as a going concern for a period of at least one year from the date we issue our consolidated financial statements,' the company said, noting its unrestricted cash, cash flows from operating activities, and availabilities and commitments under existing financing agreements 'are not sufficient to meet obligations and fund operations for a period of at least one year.'

Sunnova also said it has hired a financial advisor to assist with its debt management and refinancing efforts.

The company reported a narrower year-end loss of $2.96 per diluted share from a loss of $3.53 a year earlier.

Analysts polled by FactSet expected a loss of $1.91 per share.

Revenue for the company for the year ended Dec. 31 was $839.9 million, up from $720.6 million a year earlier.

Analysts surveyed by FactSet expected $846.3 million.

According to a regulatory filing, Sunnova negotiated a new, $185 million term loan facility Sunday with a group of lenders. The loan matures in three years and carries a 15% yearly interest rate in addition to provisions requiring the company to repay the loan in full in the event of a default.

Price: 0.67, Change: -0.99, Percent Change: -59.64