Sunrun, the second largest US installer of residential solar after Tesla’s SolarCity, has announced a “multifaceted partnership” with UK and US utility giant National Grid, including a $100m equity investment into Sunrun assets.

The deal will see National Grid jointly marketing Sunrun’s solar and storage offerings in its downstate New York service area, with the two companies exploring ways in which distributed energy resources can be aggregated to help balance and optimise the grid.