Webbing--Solar Panels

I really want solar panels!!!  There is a lot of information on them on the web.  First of all Photovoltaic technology is the process of using the sun's energy to produce electricity.  This energy can be used while being produced and the excess can be stored in batteries and used when the sun is no longer shining.  Also, the panels must be positioned to get optimal exposure to the sun for as long as possible each day.  Solar panels should face true south with a tilt angle equal to your latitude. (this is very confusing because you can also change the tilt depending on the time of year).   Another important aspect of solar is the insolation of the area you are in.  Insolation is the total number of hours per day that the solar panel will produce its rated output.  Yes, I am confused!!  I did check out the insolation map, and during January (weakest time of the year) solar panels would produce 4.0-4.5 kWh.  Uh oh.  Solar panels can't power heat and air conditioning?  Why?  Not sure I understand this.  I guess this is why there is so much information about power companies buying excess power from people producing solar power.  I'm not so worried about the heat because we will have a wood heater, but I have to have air in the summer.  The website altestore.com does ensure the solar panels ability to support an 20 watt attic fan.  With the type of external walls the house should be easier to keep cool and warm so I'm not really worried about the a/c or heat.  Plus, if I'm getting a check from the electric company it should all balance out if I have to use electric company power a lot during the summer.