Want to make Excel Dashboard/Tool which can compare pre & post data of energy consumption of application(loads) and give us comparison reports

My company and I are looking for an experienced freelancer to develop an Excel tool for Electrical energy savings. The tool should be able to calculate energy savings, graphically represent data, and compare different scenarios all according to the formulas and calculations I will provide. We prefer to communicate technical details via telephonic discussion. The freelancer should have experience creating similar tools and should present a proposal for development.