By Diego Mendoza, CNN(CNN) — Thunderstorms have disrupted Cuba’s attempt to restore electricity, the national grid operator said Monday, less than a day after the country suffered its sixth nationwide blackout of the year. The outage comes as the US continues imposing a blockade of oil that Cuba uses to power its aging energy infrastructure. The island of roughly 10 million people suffered two outages in March and three in July. Without fuel for taxis, for example, some drivers in Havana are using solar-powered tricycles to move people around. Juan Carlos López contributed reporting from Havana.