Up 255%, This Solar ETF Will Have Even More Days in the Sun A recent pullback in clean energy stocks portends opportunity with several exchange traded funds, including the Invesco Solar ETF (TAN). New data is confirming the durability of solar power during the coronavirus pandemic. TAN seeks to track the investment results of the MAC Global Solar Energy Index, which is designed to provide exposure to companies listed on exchanges in developed markets that derive a significant amount of their revenues from solar power equipment producers, including ancillary or enabling products. Over the past year, the fund is up a whopping 255%.