This is done via a bi-directional electric meter. When excess energy is generated, the meter spins backwards. The unused energy goes to the regional electricity distribution system (the grid). The home that generated the excess power (in this case, the Spring Lake Inn) is credited.
At night or in cloudy weather when the solar panels cannot generate sufficient power for household use, the meter spins forward. Power is drawn from the grid. Utility bills are low because of accumulated energy credits.
The difference between power generated and power used is called net metering.
