As Maine continues to expand its investments in renewable energy infrastructure, organized labor is notching some policy victories aimed at boosting union workers’ presence in the green economy.This week, Gov. Janet Mills allowed a new law to go into effect without her signature that will require developers to pay prevailing wages to workers on commercial, mid- and large-scale renewable energy projects. And it will also allow regulators to give extra weight to bids for big public renewable energy projects that include agreements with unions or employee-owned contractors.