BISMARCK — Xcel Energy, a power company delivering electricity to 97,000 North Dakota customers, is proposing the biggest electricity rate increase in recent North Dakota history. ADVERTISEMENTAccording to Xcel Energy, over 86% of those energy users are residential North Dakotans and the rest are industrial or commercial businesses. Stacy Eberl, a spokesperson for the North Dakota Public Service Commission, which regulates electricity costs, said Xcel Energy’s latest rate hike request is the biggest she’s seen in over a decade of working for the commission. Public Utilities Division Director Victor Schock, who has worked for the Public Service Commission for 11 years, also said it’s the biggest rate hike request he’s seen. It’s “likely” the biggest request to increase electricity rates the state has ever seen, he added.