The power is back on for the first time in 15 hours and Benitez, a fourth-year architecture student, needs to get his assignment in fast before the electricity cuts out again.Desperate times call for desperate measures in crisis-hit Cuba, where a US fuel blockade -- part of a pressure campaign which Havana fears will culminate in a military intervention -- has aggravated an energy crisis, leaving people without power for up to 20 hours a day.In February, the government moved university classes online, part of a raft of measures aimed at conserving electricity.But distance learning has proven challenging in a country with patchy internet and dwindling power supplies.Students struggle in fields like architecture, which require regular feedback and direction from insructors."Having direct contact with the teacher is really important," said 28-year-old Benitez, who has to ask all of his questions via WhatsApp or Telegram.With only one oil tanker mooring in Cuba in the last four months, the situation is rapidly deteriorating.The government announced that it had run out of diesel and fuel oil needed to power the generators that supplement the output of its seven dilapidated power plants.And as public transport grinds to a halt, so too have students' social lives.Benitez, who cooks over an open charcoal fire, hasn't left his neighborhood of Punta Brava since February.Self-starters required