Solar Heating

There are two distinct goals of solar systems:
a) generate electricity
b) produce hot water

Electricity producing photo-voltaic cells not only produce
electricity for the house, but also, produce excess
electricity (co-generation) to "sell" back to the utility
company.  The payback of electricity producing systems
typically has about a 10 year payback for residential
installations

There are two types of hot-water producing systems
a) high volume; small temperature differential
b) low volume; high efficiency (temp differential)

High volume, small temperature differentials are
relatively inexpensive to install and are typically used for
swimming pools (black panels at right).   The square feet
of panels is typically about the surface  square footage of
the swimming pool.  The technology is straightforward -
water is pumped to the bottom of each panel and then
forced up through a series of black thin channels.  
Surfacing at the top of the panel, all exits are routed to
the highest point in the system and then returned to  the
pool.

Domestic hot water heating requires higher efficiency,
glass and copper pipe systems in order to heat the water
to typically 160 degrees.  A couple hundred feet of panels
on an appropriately south-facing roof is all that is needed
to heat most residences.  A boiler is required to
supplement the solar heating in winter or during periods
of unfavorable sun.