Xcel Energy-Colorado has filed a request for a new electric rate increase, which follows a recently approved natural gas rate hike and a $182.2 million jump in revenue for electric service that took effect in April. The request submitted to regulators Wednesday proposed a $312.2 million revenue increase. ... Critics of Xcel’s recent rate cases have accused the utility of “a pancaking” of increases. The PUC approved a $64.2 million rise in the utility’s natural gas rates in October. Regulators slashed the utility’s original proposal by $138 million. ... If the increase is approved, the typical residential bill would rise...