 Energy suppliers are not doing enough to help low-income and other vulnerable customers during what is expected to be an exceptionally difficult winter, according to regulator Ofgem, which found many showed signs of severe weaknesses. Ofgems review included 17 energy firms, including Shell PLC LSE:SHEL, NYSE:SHEL, which was found to display moderate weaknesses, as well as Centrica PLC LSE:CNA owned British Gas, Good Energy PLC, Scottish Power and Octopus Energy. 