From a fact sheet pubilshed by Focus on Energy:

Pole-mounted solar electric systems offer an excellent opportunity for businesses to display a commitment to renewable energy. Also called solar flags, these systems are economical because they tend to be small. Today, solar flags are seen outside business establishments, in parking lots and in city parks. Not only do solar flags generate electricity, they also promote clean energy technology in a highly visible way.

When most people think of solar panels, they think of roof-mounted systems. However, roof-mounted systems are often hidden from view, partially shaded by trees, or not facing the best direction to capture solar energy. Solar flags can be installed in highly visible locations and positioned optimally to capture sunlight. Installing a solar flag does not involve attaching anything to your building, and the occasional maintenance requirements will not include a trip to the roof. Also, unlike roofmounted systems, pole-mounted solar flags do not need to be removed and reinstalled when the roof is replaced.

Solar electric flags can offer great economics and a relatively low cost. They are available in different sizes and prices (see Table 1). Costs tend to be significantly lower for business owners who pay federal taxes. If your electric utility offers a solar buyback rate, your solar flag can pay for itself in less than ten years. What’s more, some utilities offer additional incentives to nonprofit organizations and government agencies.