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Frequently Asked Questions

Q: What is the systems power rating?
A: The installation is a 20 kW photovoltaic system.

Q: How much of this building will this photovoltaic system power?
A: On an annual basis we are predicting 60% of the electrical energy for the building will be supplied by this system.

Q: What type of panels are those and are they safe to walk on?
A: These are Amorphous Silicon panels made by Uni-Solar Systems, you can walk on them with soft-soled shoes.

Q: How many houses would this system power?
A: This system would power two standard American houses.

Q: Why is half of the photovoltaic system on both the east and west sides of the building?
A: This is because of the north-south orientation of the building which was selected for passive ventilation reasons. To accommodate the different orientations of the arrays the east and west systems are electrically independent, and work together to power the building.

Q: What is the operating voltage of the system?
A: 600 VDC is the peak operating voltage for the DC side, and 208 VAC for the AC side. The DC voltage varies depending on the amount of sunlight.

Q: This system is in Grand Rapids, Michigan, is snow a problem?
A: 20% of the light still gets through which is enough to melt the snow off of the panels, and a non-stick surface on the panels assists with this process.

Q: How is the energy stored for use when the sun is not shining?
A: This system is connected completely to the electrical utility grid, which means it will put power onto the grid when there is more then enough for the building, and it will draw power from the grid when there is not enough sunlight. There is no battery storage system.