Revenue was $2.33bn, down from $2.67bn a year earlier.

Net income through September was $43m versus $306m a year earlier.

NRG mainly operates a fleet of fossil-fuel generation assets and some retail electricity operations in the US. Through an aggressive acquisition strategy in the past three years, it has become one of the biggest developers of solar power.

NRG through its wholly owned subsidiary, NRG Solar, is now vying with NextEra Energy Resources as the largest US solar generator.

Solar