San Francisco Chronicle: Broad fields of giant solar panels as big as houses tilt toward the sun in this torrid patch of the Iberian peninsula. Arranged in tidy rows, like the vineyards and olive groves that quilt the typical Portuguese landscape, the panels belong to a solar power plant that comes on line this month and is due to be the world’s largest when it is completed later this year. Portugal, one of the European Union’s least conspicuous countries, is in the vanguard of the continent’s rush to …