The move will complement NRG Energy’s network of independent solar installers and dealers, as well as expand the residential solar services in the US.

New Jersey-based RDS has around 475 employees and provides solar sales and installation services in Northeast US.

RDS will commence operations under the brand NRG Residential Solar Solutions from April 2014, while its headoffice will remain in Wall Township, New Jersey.

NRG Energy president and CEO said David Crane said the time is now for the company to ramp up its efforts to bring the benefit of self generation to millions of present and future retail electricity customers.

"Roof Diagnostics Solar, its management and all of its dedicated employees are a perfect fit with NRG as together we take a big step towards a national residential solar business platform," added Crane.