Remove peels from lemons; squeeze fruit, reserving 1/3 cup. Save remaining juice for another use., In a large saucepan, combine sugar and water. Bring to a boil over medium heat. Reduce heat; simmer, uncovered, until sugar is dissolved, 3-5 minutes, stirring occasionally. Remove from the heat; add tea leaves and lemon peels. Cover and steep for 15 minutes. Strain tea, discarding tea leaves and lemon peels; stir in lemon juice. Cool to room temperature., Transfer to a container with a tight-fitting lid. Store in the refrigerator for up to 2 weeks., To prepare tea: In a tall glass, combine water with 1/4 cup concentrate; add ice.