The road to today’s Hall County Board of Commissioners’ vote on whether to contract with Siemens and Pepco for multimillion-dollar, energy-efficiency projects has been fraught with shifting financial estimates, unknowns about future utility costs and concerns the technology might soon be out of date. For several years, county officials have been looking to make a significant investment in lighting and water retrofit projects, as well as other energy conservation measures, as a way to become more environmentally friendly and reduce operating costs. But looking at specific projects only began within about the past year, Commissioner Craig Lutz and others have said.