01/28/14 - Tuesday's Topical Currents looks at the history and viability of solar energy. Portugal leads the way in European solar energy, with 70% of its electricity generated from the sun. Some 20% of California’s electrical grid is solar powered. We’ll speak with energy expert John Perlin, author of LET IT SHINE: The 6,000-Year History of Solar Energy. In the second half of the program, an interview with Alice Hoffman, author of “Survival Lessons.” That’s Topical Currents . . . Tuesday at 1pm.