Green power generation isn’t easy for large buildings. Some high-powered businesses, such as casinos and office buildings, would need a solar power grid the size of Rhode Island (the smallest state, but come on).

The Revolution Door adds a turbine to the revolving door of power hungry businesses. As people come and go through the doors, power is generated. Might not be enough to power a whole building, but could contribute to a hybrid effort. — Andrew Dobrow

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