ActiveFigure 8.17 Passive vs. active solar systemsA residential photovoltaic system consists of solar panels to absorb and
convert sunlight into electricity, a solar inverter to change the electric current
from DC to AC, and a battery storage and backup system. Systems range from
small, residential rooftop-mounted systems with capacities from a few to several
tens of kilowatts, to large utility-scale power stations of hundreds of megawatts.
Nowadays, most residential systems are connected to the electrical grid with any
extra electricity generated sold back to the local power company. A residential
rooftop system produces about 95% of net clean renewable energy over its
expected lifetime of about 30 years. Because of the exponential growth of
photovoltaics, prices for PV systems have rapidly declined in recent years.
Federal, state, and municipal governments can encourage the adoption of
more solar energy systems by:
■ Providing tax incentives, credits, subsidies, and/or low-interest loans to
manufacturers and/or homeowners
■ Requiring all new construction to include some type of solar energy
system that is appropriate for the area