Pedal power, which is used to juice computers, home appliances, cellphones, sound systems and Christmas trees, is generating interest. A group of Temple students, who run a company which sells T-shirts with environmental messages, will be using four bicycles to power the sound at the Manayunk EcoArts Festival. As we brainstormed marketing ideas, we decided it would be cool to have a concert powered by people riding bikes, said Verde Styles' CEO Nish Patel, a senior finance major.