A revolution in the renewable energy source domain is picking up speed after a new study released by the International Renewable Energy Agency (IRENA) revealed plummeting costs for wind and solar power. The International Renewable Energy Agency notedof competitiveness between 2013 and 2014. As Grist's David Roberts points out in from the report,power from geothermal, hydro and onshore wind are in the same competitive price range as traditional fossil fuels. (MORE: ) Since the end of 2009, solar photovoltaic (PV)...