TURIN, Italy (Reuters) – Carmaker Stellantis aims to take a decision by the end of the month on a plan to make its plants more self-sufficient in terms of their energy requirements, Chief Executive Carlos Tavares told a news conference on Tuesday. Options included investing itself, finding outside investors or an industry partner to facilitate the moves as energy prices soar and the fear of shortages looms large, he added. Tavares said last week that the Franco-Italian carmaker was considering significant investments to produce energy for its European facilities on site and also working on mea…