09.13.12

The Number: 144

That's the number of Walmart stores with roofs covered in solar panels. In today's installment of The Number, global business editor Daniel Gross and reporter Alex Klein reveal why corporate giants are leading the solar charge.

That's the number of Walmart stores with roofs covered in solar panels. In today's installment of The Number, global business editor Daniel Gross and reporter Alex Klein reveal why corporate giants are leading the solar charge.