Here are the facts on the most popular Alternative Energy Systems:
Wind Generator - installed cost is about $18,000USD for a Skystream and requires a LOT of wind to be useful, like 20mph per day. It is Grid Tie - provides power directly to your property and excess to the grid, and shuts down in a power outage (UL 1741 rule). 12mph average annual wind produces around 400kWh/mo power.
Photovoltaics - installed cost for 3kW is around $22,000USD. It is Grid Tie - provides power directly to your property and excess to the grid, and shuts down in a power outage (UL 1741 rule).
Battery Backup to Grid Tie System - for an additional $7,000USD you can add a battery bank and inverter to provide emergency power in case of a power failure. The batteries will provide one day under normal usage and two days if you are really conservative with your power loads. An additional battery bank to double your time off grid would cost an additional $4000USD.
Totally Off-Grid - This is a combination of the Battery Backup system mentioned above and the Photovoltaics (or Wind Generator) to provide the recharging power for the batteries. A total system is around $34,000USD with battery capacity for four days without sun.
Backup Generator - in case of prolonged power outage or you are off-grid and you don't have sun (PV) or wind (turbine) for several days then you are forced to recharge the batteries using a conventional fossil fueled generator. I use a 13kW generator that attaches to the rear PTO of my tractor running on B20 biodiesel.
Solar Hot Water - two Evacuated Tube Collectors, an 80 gal stainless steel storage tank, and a backup on-demand hot water heater (Toyotomi uses oil/biofuel, Rinnai uses propane) will provide domestic hot water (DHW) for up to four people and the backup heater will only run 15-20% of the time annually, saving around 200 gal of fossil fuel. A larger system of 6 collectors, 300 gal storage tank, and backup heater when used with radiant floor heating can save up to 600 gal of fossil fuel annually. These figures are based on the climate in New England.
Costs - your out of pocket costs for these systems will vary according to any state and local utility rebate/incentive programs.
Wood and Pellet Stoves are also a 'carbon neutral' and cost effective way to heat a building in northern climates where biomass (trees) are abundant and locally available to reduce shipping costs.
Further information is available on my website:
http://solrheatsystems.com
Aside from a global public release of free energy technology (one can only hope) these systems are the current 'state of the art' and there are no game changing developments or technologies in the works that will be commercially available for the next 3-5 years. A lot of unscrupulous people will be drawn to this industry to rip people off as people go into panic mode over the current energy crisis. If you see something that seems too good to be true, it's probably bogus. Do your homework and select a system that's been around with a proven track record.
Caveat: my advice is worth exactly what you just paid for it!
