Who owns NRG Electric?

Could you please clarify for me who exactly owns NRG Electric? Is it a publicly traded company, or is it privately held? Are there any major shareholders or investors that have a significant stake in the company? Additionally, have there been any recent changes in ownership or management that I should be aware of? Understanding the ownership structure of NRG Electric would be very helpful in gaining a better understanding of the company's operations and potential future directions.