BRUSSELS — Electricity will be taxed at a lower rate than fossil fuels across the bloc under a bill that the European Commission is poised to unveil next month, according to two EU officials. The initiative is part of a wider strategy to power the EU with more electricity from nuclear energy and renewable sources, such as solar panels, wind turbines and hydroelectric dams. “This is the second fossil fuel crisis in just a few years. We need to scale up homegrown, affordable, reliable energy,”