Solar cells, or photovoltaic cells, are banks of devices that use semiconductors to generate electricity directly from sunlight. This electricity will be used to offset the carbon footprint of the home. Drawing less power from utility providers -- whose electricity is produced by traditional, non-renewable resources -- eases the demand on the power grid. We are installing approximately 742 square feet of photovoltaic panels to produce 7 kilowatts of energy; this will be sufficient to run the house and will likely provide excess electricity. The excess power can be fed back into the grid and the utility company will credit you for creating from a renewable resource -- the sun! We are also installing a set of rooftop panels for our solar water heating system; this is supplemented by tankless water heaters as detailed in the finish plumbing section.