This story was originally published by NEXTpittsburgh, a news partner of PublicSource. NEXTPittsburgh is an online publication about the people advancing the region and the innovative and cool things happening here. Sign up to get NEXTpittsburgh free. When the sun does shine again in our region, it will bring more than just smiles to residents in the Allegheny River boroughs of Etna, Sharpsburg and Millvale. The Triboro communities are the next locales where Solar United Neighbors (SUN) is offering a solar co-op to make buying residential rooftop solar panels easier and less expensive. But, says Henry McKay, SUN’s state program director, anyone in Allegheny County who is interested can join this co-op.