Pharmaceutical chain Walgreens has started work on what it calls America's first "zero energy" superstore. Its Evanston store, located some 20 miles away from its headquarters, will utilize more than 800 solar panels, two wind turbines, and geothermal energy to — it hopes — provide enough energy to keep the store running without additional power from the grid. Walgreens is fairly confident it can easily reach that goal; it says that its renewable energy sources can generate 256,000 kilowatt hours (kWh) of electricity every year, and estimates its store will use just 200,000 kWh. It does emphasize that both those figures are only estimates — weather will play a large part in both energy demands and output.

Of course, building a single energy-efficient store isn't going to make a huge difference to Walgreens' energy footprint. The company has over 8,000 retail locations throughout the US, not to mention a large supply chain that's unlikely to be running on thin air. That said, Walgreens has also committed to cut its overall energy use down by twenty percent across its stores before 2020, and this is a solid start.