There seems to be a plethora of companies and methods, some creating a new system with each site.  That is true because so much goes in to getting off the grid; location, how much sun, how the temperature ranges in that area, (like New England-can you use solar there?), what is the consumption, how far away is the collection from the use and so much more.  The most important to us, I believe, is lowering our dependency, your carbon footprint and your ghastly heat & energy bills.

Since I am doing a series of alternative ways to heat/cool, provide energy and heat water, I thought it best to do an additional overview of Solar.

Not only do Solar systems provide clean energy, they are considerably quieter and can meet the entire heating needs of a home or business. These systems are a way to collect, store, and disburse the sun’s heat and energy and two basic main categories; Passive and Active Solar.

Passive solar heating systems can also use building design features to gather energy.  See building design – SOLAR using south-facing walls allows large amounts of sun energy or thermal mass to be collected.

Active solar can be added in at the time of building or easily retrofit into an existing structure. They rely on solar collectors usually placed on a South facing wall or roof to gather the sun’s energy. Economically Active systems are most cost-effective when they are used for most of the year and when displacing more expensive heating fuels, such as electricity, propane, oil, etc.. tax exemptions or deductions for solar energy systems. See Tax Credits for renewable energies.

The costs of active solar for heating heating range from $30 to $80 per square foot of collector area that last considerably longer than their  dirty fossil fuel brothers and most  with warranties of 10 years or more and should easily last decades longer. If domestic water is included the cost effectiveness is much greater.

Two types of active solar heating systems exist; one uses an antifreeze or liquid medium and the other uses air. Liquid systems are more often used for storage like in radiant, boilers with hot water radiators. see more specifics on each here:
http://apps1.eere.energy.gov/consumer/your_home/space_heating_cooling/index.cfm/mytopic=12510
http://apps1.eere.energy.gov/consumer/your_home/space_heating_cooling/index.cfm/mytopic=12500

Usually utilizing a mixture of technologies is the most comfortable and most financially viable.